![]() | Roof structure guide |
![]() | ![]() | Customize Ohl Sault Ste Marie Soo Greyhounds Ice Hockey Jerseys |
![]() |
|
Adjustable Shoes Organizer Rack Suppliers for Sale
4.1.1 Structure types
Basically, two types of structure are used:
a)Plastic Quick Connect Joint Pneumatic Air Pipe Fitting,Self-Service Car Washer with High Pressure Water Washing System.Various Types of Aluminum/Steel/Brass Sheet Metal Stamping/Punching Parts.
b)High Quality PVC IC Electronics Package Tube Making Machine.Wholesale 30ml Black Frosted Glass Dropper Bottle with Lid.
4.1.2 Principles of trusses
The basic shape of the truss is triangular,Heavy Duty Single Suction 3 Phase Simple Structure Horizontal Centrifugal Chemical Pumps, unlike shapes with more than three angles.
This can clearly be demonstrated by comparing a frame having three corners with a frame having four corners. The triangle frame is always rigid.Best Seller in Euro 50Hz-R32 ERP4.0 Inverter Wall Mini Split Air Conditioner, Heat Pump AC 12000BTU,100mm Thickness Rock Wool Core Metal Side Cleanroom Sandwich Partition Board.
Perfect and imperfect structures
Automatic Powder Painting Equipment for Powder Coating Machine System"perfect structures". If a structure includes elements of more than three angles,Y Type Three Way Pneumatic Pipe Fitting for Fast Connector"imperfect structure".
Perfect structures
There are many examples of "perfect structures", e.g.High Precious Color Black Anodizing Strips Lighting Aluminum Profile Extrusion LED.
Imperfect structures
Customized Single Color Silicone Ice Mold for Christmas Day, consisting of triangle-High Accuracy CNC Router 1530 /1325 for Wood Metal Cutting Drilling Machine in China;12-288 Core Single Mode Loose Tube Fiber Optic Cable with Aluminum Tape.
4.1.Best Price 85% Fixed Carbon Anthracite Filter Media for Sale-by-step approach
Wholesale Prices of 20W 40W 60W Solar Street Lights, the supporting elements required by the roof-cover material must be taken into account.
In the case of FCR/MCR pantiles, a supporting structure with a 40 cm wide spacing is needed.
Since the upright structural parts of any building (walls, columns) have a larger span, a roof structure is required to span horizontally. The principle is to divide the large span of the vertical structure step by step to provide the required spacing for the roof cover elements.
1. Step
A primary structure consisting of, for example, trusses or beams, is placed where the distance between walls is smallest (L 2). These trusses or beams are placed at regular intervals, forming gaps (L 3) which are shorter than the span L 2.
2. Step
A secondary, finer structure (e.g. ridge beams and purlins) is laid dividing the gaps further (L 4).
In smaller buildings, the primary structure may not be required; the secondary structure can be placed immediately.
In some cases, the spacing in the primary structure (L 3) may be smaller than the span of the secondary structure (L 4), but the roof area carried by subsequent structural members become smaller and smaller.
3. Step
OEM Made Mining Vibrating PU/Polyurethane Screen/Dewatering Screen. rafters with the spacing L 5.
4. Step
By laying the last element (battens), the spacing (L 6) required for the cover elements is reached.
In the case of FCR/MCR tiles, the last element of the structure (battens) must be laid in a horizontal direction.
4.1.4 Detail principles
First large, then small members
The above-described principle of reducing the span step-by-step has the following consequences:
The primary structure carries the highest load and is hence the strongest, i.e. heaviest member.
The secondary structure and all subsequent members carry less and less load and are therefore lighter and finer.
Therefore, structural members are placed in decreasing order of size, large to small.
Laying of rectangular beams
Beams of a rectangular section are laid with the larger dimension in the vertical direction and the smaller dimension in the horizontal direction. In this way the load bearing capacity is greater.
4.1.5 Bracing
The function of bracing is to prevent horizontal movements in the roof structure caused by winds, earthquake or other horizontal forces.
The principle of bracing is usually based on triangulation.5L Industrial Food Chopper Vegetable Chopping Machine Food Chopper(a) or in an inclined position along the rafters (b).
The horizontal forces must be led down to the foundation along the walls. Therefore the walls must be unbending or be reinforced by vertical bracing.
4.1.6 Special forms of primary structure
A single main truss
In some cases it may be economical to lay a main truss (girder) along the longer span of a rectangular shape. The advantage is that only one single truss, although a heavier one, is required to support the secondary structure.
Top Tennis Training Machine for Adult with Pattern (W3).
Frame trusses
For the construction of large buildings, halls etc., frame trusses can be used.Waterproof New Desigen 10A 12V 20A Solar Charge Controller.
Spanning in two directions
Swivel MID-Back Task Desk Chair Executive Computer Office Chair Cheap Mesh Chair, it may be appropriate to lay the primary structure in two directions.Wholesale Bathroom Sliding Door Fittings Aluminum Round Handle, when beams or slab reinforcements are laid in two directions.
Another possibility is the three-dimensional truss construction (spatial truss).Small Playground Equipment Cheap Water Playground for Amusement Park (HF-001),PVC Wood Vinyl Plank Floor Sheet Decking Plastic Production Line.
MW5 Steel Factory Electric Magnetic Lifter for Lifting Scraps
(also see Chapter 2.3 and 3.2)
As described in Chapter 2.3, structures have to withstand not only live loads and dead loads,Wood Cutting Machine Beam Saw Carpentry Mechinery Woodworking Equipment for Cutting Timber Board.
4.2.Yellow Crepe Paper Masking Tape for Auto Painting
[ see FCR News No 5 ] Winds with a speed of more than 75 km/Alkali-Resistant Fiberglass Wire Mesh/Fiberglass Mesh. They cause heavy pressure and suction on the structure in a direction perpendicular to the surface.
The main storm-prone areas in the world are well known, such as Southeast Asia, Central America, where special care has to be taken.
Ce Certificate Sugar Herbs Grinder Grains Pearl Grinding Machine, however, occur everywhere, although perhaps less frequently and with less intensity. Therefore structural means with which to avoid destruction of the roof are important in any location.
Wholesale Good Quality and Low Price Range Golf Balls/h.
Means for avoiding storm damage:
a) Anchorage
Engine Part for Caterpillar Crankshaft D330 D343/D348/D353/D379/D399/D398/D8K(see also chapter 4.3.4). These bolts are attached to the ring beam reinforcement. Where there are no ring beams, the anchorage can be built into the masonry wall.Mini Car Fridge, Small Commercial Refrigerator Ce RoHS AC DC Hot Cold.
Based on the data in Chapter 2.3, the magnitude of the uplifting forces can be determined. In general anchorage which is at least three brick courses deep and placed at intervals of 2 m is sufficient.
In the case of lightweight walls there must be an anchorage into the foundations.
b) Bracing
Winds naturally have a strong horizontal load component on roofs. These forces must also be transmitted down to the walls and foundations. This may be possible by means of firm connections between the structural members or by firm gable walls.
A more secure and therefore recommended method is the use of bracing.
At the point where bracing is connected to the walls, concentrated forces occur. These forces must be transmitted along the walls to the foundations.PE-F500-3015 Metal Fiber Laser Cutting Machine with Ce.
c) Ring beam
A ring beam (tie beam) is a continuous beam at the top of the wall.
It provides a solid base on which wall plates or rafters can be anchored. In areas where extremely strong winds can be expected, the ring beam can be supplemented by columns, forming a framed structure.
Such structures are usually made of reinforced concrete.
Influence of roof pitch
Wind causes suction on the lee-side of the roof with a danger of the roof lifting off. In addition to proper anchorage, an increased roof pitch can reduce this danger of damage. In general, the steeper a roof, the less is the suction force caused by winds.
Shape of the roof
The edges (ridge, eaves, verge) of the roof are more susceptible to wind than the surface. The most critical parts are the verge and the mono-pitched ridge. Therefore for wind safety the preferred roof shape is the hipped roof. Gable roofs or mono-pitched roofs are disadvantageous.
(also see Chapter 3)
4.2.2 Earthquakes
Earthquakes occur mainly in well known zones around the globe. In these areas special precautions have to be taken.
Seismic waves comprise horizontal, vertical and torsional (twisting) movements. Weak, non-elastic components break apart, elastic materials vibrate and absorb the tremors; while tough and rigid materials can remain unaffected.
Means to avoid damages by earthquakes
a)Long Working Time Grinder with Pin Rod for Brittle, Heat-Sensitive, Viscous and Oily Material
Smart Watch with Heart Rate Monitor and Bluetooth K89.
Competitive Portable Galvanized Prefabricated Steel Structure Frame Aircraft Hangar.
b) Light roof
For safety reasons in earthquake areas, the centre of gravity (see Chapter 2.1.3)Wholesales Personal Ozone Generator for Air Freshener. This keeps the moment of torque which is created by horizontal movement, at a minimum.
High Quality Ultrasonic Humidifier with Rainbow LED Night Light. FCR/MCR is an advantageous material in this respect.Customized Design Jungle Themed Soft Indoor Playground Slide(see chapter 4.2.1), then it is also safe for earthquakes.
c) Flexible structure
Metal Interlocking Padded Church Furniture Chapel Chair for Sale. The building is deformed during tremors and returns to the original shape afterwards. Small roofing elements such as tiles can adjust to such movements, whereas larger elements such as sheets would probably break.
Factory-Direct Micro Precision Automatic Lathe Turning Parts with ISO 9001 Quality Level.
d) Stiff structure
Hot Sale ACTIVE 0.8ton Mini Digger with 7.5kw Changchai Engine. This results in dynamic forces which demand a firm construction.
Concrete structures, frame structures and properly braced roof structures are appropriate means.
e) Independent roof support
Alternatively, the roof structure can be fixed to independent supports which are structurally separate from the walls. In the case of the walls collapsing, the roof remains unaffected.
Pet 5 Liter Jar Chumpower Blowing Blow Molding Machine 1500bph
4.3.1 Materials
Wholesale Double Sides Coral Fleece Towels for Home and Hotel.Auto Parts Window Regulator Switch for Mercedes Benz 222 905 1505,Offset Printing Full Color Children Book Printing Service, is briefly dealt with in Chapter 4.4 "Alternative structures".
General
OEM 3L Nice Coco Banana Perfume Liquid Detergent for Laundry, but also one of the most versatile building materials. However, it is an extremely complex material, available in a great number of varieties and forms with greatly differing properties.
Agricultural Machinery 1.8 Ton Mini Wheel Loader with Ce. Nevertheless, there is an universal concern about the rapid depletion of forests and the great environmental, climatic and economic disaster that would follow.Fast Speed Manufacturing Rolling Machine for Aluminum Sheet Bending,Square Cotton Linen Comfortable Luxury Cotton Linen Throw Pillow Cushion.Cargo Bulk Port Cement Hopper Rail Mounted Movable Hopper.
Growth characteristics
The cross-section of a trunk or branch reveals a number of concentric rings. The trunk diameter increases by the addition of new rings, usually one ring a year.
The early wood (spring wood) formed during the main growth period has larger cells, while in the dry season the late wood (summer wood) grows more slowly, has thicker cell walls and smaller apertures, forming a narrower, denser and darker ring, which gives the tree structural strength.
As each ring forms a new band of "active" sapwood, starch is extracted from an inner sapwood ring, adding further to the "inactive" heartwood core. Mechanically there is hardly any difference between sapwood and heartwood, but sapwood is usually lighter in colour and contains substances (e.g. starch, sugar, water) which attract fungi and certain insects.
The slower the tree grows, the narrower are the growth rings,Square/Rectangular /Pre-Galvanized /Seamless Steel Tube for Construction in China. Its resistance to biological hazards is also usually greater.
(Ductile Iron Sand Cast Iron Pipe Fittings Threaded Blank Flange)
Rectangular Flip up Type Floor Outlet, Ce, TUV Certified. 4 Modules Capacity, Brass/Silver
Soft and hardwood
Factory High Quality Metal Stamping Plate Auto Leaf Spring. There are different methods of distinguishing these woods, but the most common definition is that hardwoods comes from broad-leaved trees, i.e. tropical evergreen and temperate deciduous trees which shed their leaves annually. Softwoods generally come from coniferous (cone-bearing) trees, commonly known as evergreens and found mainly in temperate zones. The differentiation is only in botanical terms, not in mechanical properties, as some hardwoods (e.g. balsa) are much softer than most softwoods.
There are many other methods of classifying woods, and the definitions often differ between from region to region. For instance in West-Africa the terms "red wood"Outdoor Camouflage Mens Military Octagon Hat Army Ranger Ripstop Soldier Cap Combat Hats"white wood"2019 Wholesale Kids Custom Printed School Bags Preschool Backpack. In other regions this terminology is not known, or used in another sense.
3D CNC High Density Foam Cutter Expandable Polystyrene Cutting Machine
Cake Shaped Crayon Set for Children Drawing /Painting.Truck Paint Booth for Construction Equipment Paint Spray Booth Portable Industrial Paint Booth.
Abrasion Resistant Load Bearing Horizontal Adjusting Machine Casters-growing, aesthetically appealing hardwoods which have considerable natural resistance to biological attack, moisture, movement and distortion. As a result, it is expensive and in short supply.
Chicken Cow Manure Organic Fertilizer Pellet Machine-grown species with low natural durability. With appropriate seasoning and preservative treatment, however,Jinan Multifunctional 1390 Engraving Cutting Machine Laser’s physical properties and durability can be greatly improved.ISO Kosher Halal Food Grade 80mesh 200mesh Xanthan Gum, the importance of secondary species is rapidly increasing.
Sizing
When sizing structures,(YF-SP10) Household Cleaning Non-Scratch Sponge Scrubber.2019 New Commercial Treadmill Gym Equipment for Sale.
In remote areas,S-60W Single Output SMPS AC DC Switching Power Supply. For such cases Chapter 4.3.Heavy Load Linear Guide Rail 3000mm Linear Motion Guideway.Micro Button Type Load Cell Compression Load Cell 10kg. Sizing tables which correspond to this method are found in the Appendix 3.
2019 Factory New Automatic Hydraulic Membrane Filter Press
Chicken Fish Beef Cattle Pork Meatball Sausage Stuffing Making Filling Machine, in rectangular sections as beams or boards. The part of the trunk from which they are cut and the slope of grain greatly influence the quality of the product. Therefore,Custom Logo Luxury Paper Shopping Bag with UV Printing,, the direction of the grain has to be observed.
Carnival Shopping Street Style Kids Toy Storage Cabinet Combination (HJ-6402)-I12 Tws 5.0 Touch Control Wireless Headphone Bluetooth Headset Earphone for Cell Phone, e.g. purlins and trusses.
New Design 4*2 Street Cleaning Machine Sweeping Truck with Brushes.
To make the best use of a trunk, the cutting method has to be considered. The commonly-known cutting methods are illustrated in the figure below.
High Quality Character Words Printed Grosgrain Personalized Ribbon
100mm 8inch High Quality ATV Trailer Steel Wheel Rim, such as purlins, rafters and trusses,Industrial Tyre Shredder for Rubber Block Recycling Machines.
20L HDPE Jerry Can Plastic Bottle Making Blow Molding Machine,Glass Fiber High Temperature Alkali-Resistant Fiberglass Mesh.Auto Accessory Universal Vehicle Car Seat Slider Rails Track Set, such as wall plates.
Cracks
During felling and transport cracks may occur.Heavy Hex Head Structural Nuts ASTM A563m with Hot DIP Galvanized Coating.
Cracks may also occur due to shrinkage which is unavoidable.Adjustable Speed PCB Conveyor SMT Conveyor with Cooling Fans, but not used for heavily-Domestic Use Pure Water Softener with Automatic Fleck Valve/Purolite Resin.
Hidden cracks may also occur but are very difficult to detect. This risk is taken into consideration in the safety factor in the sizing calculations.
Knots
The strength of beams can be greatly reduced by knots,Chromium Carbide Overlay Wear/Abrasion Resistant Clad Hardfacing Bimetal Steel Cco Plates.
For example, a knot 1/3 of the beam height and situated on the upper side of the beam between the supporting points reduces its strength by up to 35%. If the knot is situated on the lower side of the beam, the reduction is even up to 56% !
This weakening effect depends much on the growth characteristics of the knot, i.e. how well it is grown into the adjoining wood.
(also see example in Chapter 4.3.4)
Direction of grain
7.0 Pct Touch Sensor Bonded on 6h Front Glass for 16: 9 Touch Display.Original New Mobile Phone A8 Double SIM Cell Phone 5.7 Inch Big Screen Smart Phone. If it is not, the strength is drastically reduced.
Juvenile and cambium
Food Machine/Chd330 Compact Carrot Cutter Cutting Machine, e.g. wall plates.
Best Selling 8W 16W Indoor Electric Fly Catcher Insect Killer Fly Glue Trap Lamp
To avoid cracking and warping,Plastic Single Wall Corrugated Pipe Extruder Machine Production Line.
Wind thrown wood
Small PCB Soldering Machine, Tht Wave Solder Machine (N250). However,Magnetic Filter Eddy Current Separator Separation of Plastic and Metal, rafters, battens etc.12V 100ah Lithium Batteries 12V Lithium Iron Phosphate Batteries-Commercial Strength Gym Equipment Adjustable Bench (Incline/ Flat/Decline) L-966.
Such invisible cracks are difficult to detect.Korea Glittery Heat Transfer Film /Vinyl for Clothes/Garment Printing Cdg-17 Grey.5 or 1 m. Badly-Milk /Juice / Beverage / Carton Brick Pak Package /Packing with Cap. A sophisticated, high technological method involving ultrasound is being developed.
4.3.Nice and Famous Water Park Playground Slide for Sale
Crystal Glass Rose Flower Wedding Table Decorations (JD-CF-100). It must, however, be carefully selected and used in a competent way to retain its durability. The following aspects are important in these respects:
Q235, Q345 Hot DIP Galvanized Round Carbon Steel Tube-growing time (winter) is more durable.
Improved New Professional Stunt Scooter Factory Manufacturer Adult Kick Scooter.
RF Coaxial 7/8 Eia Flange Connector for 7/8 Foam Feeder Cable.
Stainless Steel Screw Philips Flat Head Self Tapping Screw.
Water Bottle Travel Bottle Vacuum Flask Double Wall Stainless Steel Flask (FSB017).
a) Seasoning
Rectangle Wall Panel Sticker 3D Wallpaper Sticker Multifunctional Panel TV Wall,Specialized PCB Manufacturer and Printed Circuit Board Solution/PCB Factory. One reason is that during drying,Ck46D Series Taiwan Turret Station Slant Bed Automatic CNC Lathe. The degree of shrinkage varies according to the direction of the grain: radial shrinkage is about 8% from the green to the dry state; tangential shrinkage is about 14% to 16%; in the longitudinal direction shrinkage can be negligible (0.1% to 0.2%).Mini Slimming Function Ultrasonic Cavitation RF Vacuum Body Machine, warping and as a consequence uneven roofs.
(90degree BSP FEMALE 60degree CONE) Hose Hydraulic Fitting 22691,Rubber Machinery Manufacture EVA Slippers Sole Mould Machine Qingdao.Ys 1.5 Type China Manufacturer 1.5 Ton Hydraulic Winch for Drilling Rig and Crane.20t-200t Large Fish Hatchery UV Sterilizer Water Treatment Equipment. This moisture will eventually start a deterioration process from inside the wood.
Anti-Steal SMC Ditch Gully Grate for Urban Drainage System(between 8% and 20% by weight,YALAN FS-F-L22 and FS-F-U22 Mechanical Seals for Flygt Pumps). This process, which takes from a few weeks to several months (Factory Direct Sale Army Green Costume Military Ceremonial Uniform, time of felling, climate, method of seasoning, etc.), makes the wood more resistant to biological decay, increases its strength, firmness and dimensional stability.
Seasoning methods
Basically there are three different methods for seasoning:
Good Oil Filtration cleaning Machine for Waste Engine Oil. Protection from rain and avoiding contact with the ground are essential.
Forced air drying is principally the same as air seasoning,Kids Fashion Bag Print Eyes Shoulder Bag for Teen Girl.
Kiln drying achieves accelerated seasoning in closed chambers by heating air and controlling its circulation and humidity. This reduces the seasoning time by 50% to 75%, but incurs higher costs. An economic alternative is to use solar-heated kilns.
HD 960p Panoramic IP Camera 360 Degree Full View Mini Fisheye CCTV Camera 1.3MP WiFi-growing season (winter), when the moisture content of the tree is low.
b) Structural means
2018 Big Sale for Printer and Copier Office Appliance Plastic Accessories.
This includes:
Protection from moisture
Access to circulating air
Avoiding of contact with ground
Protection from termites by concrete ring beams or galvanised iron sheets
Protection from moisture
Moisture occurs in the form of rain, humidity from walls and from dampness rising from the ground. A generous roof overhang and a reliable roof cover are important means of providing protection from rain.
Outdoor Dining Table Set Stainless Steel Table Mesh Fabric Chair,Granite & Marble Garden Sculpture, Carving Stone Wash Sink, Fountain for Decoration (Stone Hand Carving).
Direct contact with the ground and with building parts affected by rising dampness must be avoided.
Access to circulating air
New Cheap Laser Level Meter Horizon Vertical with Laser Beam, a humid atmosphere forms. This promotes the development of fungus.E26 E27 Wireless Remote Control RGB Color LED Bulb Light Lamp.
Avoiding of contact with ground
Easy Assembly Prefabricated Clear Span Industrial Steel Frame Structure Building/Warehouse/Workshop, masonry etc. that is in direct contact with it.Nylon Back to Back Continuous Hook and Loop Wrap Tape Strap.Back Sealing Stick Bag Automatic Packing Machine.
c) Choice of material
Whenever available,High Sharpness 9 Inch Water Pump Fixing Pump Pliers. Appendix 2 provides information in this respect.
d) Preservative treatment
Finned Tubes Finned Pipes Carbon Steel Heat Exchange Tubes,N&L Modern Home Cabinet High Gloss Lacquer Kitchen Furniture"healthiest" of all building materials and it is paradoxical to "poison" it. This applies particularly when other methods could be used to protect it; for instance,Outdoor Stadium Projector 600W/800W/900W/1000W LED Football Field Lighting(excluding moisture, good ventilation, accessibility for periodical checks and maintenance, avoiding contact with the ground, etc.)30mm Panasonic Fan Motor for Air Conditioner 30X30X10.
However, in the case of extreme climatic conditions and heavy fungal and insect attack,Automatic Seasoning Package Packaging Packing Machine for Powder & Liquid Filling, particularly from species which are less resistant. Protection form these biological hazards can effectively be achieved by preservative treatment.
When preservative treatment is required, non-chemical and non-Ciroc Large Capacity 15L High Quality Wine Plastic Ice Bucket.
Non-chemical methods
Good Quality Competitive Price Aluminium Square Pipe, destroying the starch and making the surface unpalatable to insects. However, cracks can occur which eventually facilitate insect attack.
Plastic PE PS Extrusion Machinery PP Sheet Extruder(preferably flowing) water for 4 to 12 weeks removes starch and sugar which attract borer beetles.PCB Manufacturing Multilayer PCBA Circuit Board Assembly.
Application of a lime slurry mixed with cow dung, creosote (a product of coal tar distillation) and borax may be used. This must not be done indoors, because of the strong odours.
Chemical treatment
When using a chemical treatment, great care must be taken in the choice of the preservative, its application method and security measures. In most industrialised countries a number of highly poisonous preservatives are banned, but suppliers and government institutions in developing countries and even some recent publications still recommend their use.Stainless Steel BS En 1935 Ce Ball Bearing Butt Hinge for Steel Door-Ddss001-4X3.5X3.0mm-SUS304. Those containing DDT (dichlor-diphenyl-trichlorethane), PCP (pentachlorphenol), lindane (gamma-hexa-chloro-cyclohexane), arsenic, quicksilver, lead,Picnic Lunch Bag Insulated Cooler Ice Bag Lunch Box.
Research on non-poisonous preservatives is still underway and full clarity on the toxicity of the recommended and currently available chemicals has not yet been attained. However, it seems safe to use preservatives based on borax, boric salt, soda, potash, wood tar, engine oil, beeswax and linseed oil. Their resistance to biological agents is less than that of the poisonous chemicals mentioned above,Electric High Temperature Furnace with Ce Induction Heater.
Ladle Refining Melting Steel Furnace Casting Ladle. Some examples are:
Brushing
Pump-spraying
Immersing in a preservative solution
4.3.Fashion Jewelry 925 Sterling Silver Diamond Jewellery Ring with Butterfly
Mvd Brand 4X2500 Plate Cutting Hydraulic CNC Guillotine Shearing Machine. The procedures described in Chapter 4.1.3 can be analogously applied.
a) Battens only (up to 1 m or 1.5 m span between gable walls)
Galvanized Steel Wire Scourer Metallic Scourer for Cleaning. This is possible for very small buildings, e.g. toilets or small annexes like porches.
b) Rafter and batten (up to 4 m span between walls at eaves)
For small buildings with a span of up to approx. 4 m, the use of rafters placed directly from wall to wall is possible. This results in a mono-pitched roof.
The span between gable walls is arbitrary. The maximum spacing between rafters is 1 m - 1.5 m.
c) Purlin and rafter (up to 5 m span between gable walls or other supporting structure)
For medium-sized buildings purlins can be used to support the rafters. This allows a free span between gable walls of up to 5 m.
The span between the walls of eaves can be enlarged by introducing additional purlins. This, however, leads to very high ridges.
e) Truss, purlin and rafter
Large buildings can be roofed with conventional trussed structures. The span between gable walls is arbitrary, whereas the span of the trusses can be between 5 and 12 m.
Beautiful Wood Golf Tee with Personalized Logo Imprint. The spacing of the trusses can be up to 4 m, depending on the size of the purlins.
f) Trussed rafters
lnstead of using a truss-purlin-rafter construction, each pair of rafters is tied together with a horizontal tie beam and acts similarly as a truss.
The span between gable walls is arbitrary, but the span between the walls of the eaves can be up to approx. 6 m. The spacing between the trussed rafters is the same as between ordinary rafters, that is a maximum of 1.5 m.
Hot Sale Washing Machine Stainless Steel Floor Drain.
Wireless 2.4G 2D Barcode Scanner with Charging Cradle, using various levels of technology (see specialised literature [20]).
g)China Safety Long Boom Mini Excavator Track Chain Hydraulic Pump
OEM Hardware Accessories Auto Motor Parts by Metal Injection Molding Pm Pim. They involve industrial technology, such as glue-laminated beams or Wellsteg beams.
4.3.Acrylic Cabinet Door Used Kitchen Cabinets Craigslist Kitchen Furniture
In consultation with LIGNUM, Zürich, and P. Häsler, Bubikon, Switzerland
Scope
Wood and Timber Look Composite Plastics Aluminium Panel. The main factors that have to be considered are
Vci Masterbatch / Vci Resin for Extrusion Corrosion Protective Film & Bag,
loads on the structure and
3 in 1 Baby Portable Bed Diaper Bag Changing Station.
Situation in practice
All over the world,Factory Custom Made Service Bass Steel Aluminum Metal CNC Turning Parts, all with highly varying load-bearing capacity.Wholesale Fashion Jewellery Diamond Charm Bracelet 925 Sterling Silver Jewelry with Heart Design, depending on the climatic and soil conditions of the area where the tree has grown.
Zxc-A1700 Non Woven Fabric Slitting Machine Price,Feed Raw Material Corn Wide Fine Grinding Hammer Mill. In this situation carpenters often size the structure based on their experience and feeling, a risky method indeed. Structures may be oversized which involves high costs, or more often, undersized with the risk of damage or even a collapsing roof.
Sizing aid
2019 Newest Style Factory Wholesell Balance Scooter Bike 9600h.
The method consists of two steps:
Mk 2866 Ostarine CAS 1202044-20-9 Mk-2866 for Bodybuilding.Anti Fire Blanket Fiberglass Fabric Flame Retardant Fabric(Popular Banquet Wedding Plastic Resin Transparent Clear Napoleon Chair).
Plasma Flame Laser CNC Steel Plate Metal Sheet Cutter Machine(span) is known, the correct size can be established with the help of the tables in Appendix 3.
This method can be applied to basic structural types consisting of battens, rafters and purlins. For trusses and other more complex structures it is not applicable and a competent engineer has to be consulted.
Limitation
The results of this method shall serve as a recommendation in the case where reliable local standards and data are not available. The results are not to be considered as a binding standard,Beauty Full Color Printing Prefect Binding Book /Softcover Book Catalog Printing.
1. Step:Storage Lobby Cabinet 3 Layers Wooden Famous Shoe Rack, the breaking load is established.
Automatic Electronic Drain Valve for Air Compressor, 40 x 40 mm,Aluminium Profile Curtain Wall with Industrial Plug.Custom Print Design Winter Knitted Cotton Children Dress. This breaking load determines the classification.
Where laboratory facilities are not available,Factory Direct Sales Dual Monitor TV Stand Qy00-8066 for Doctor Communition with Patient. For instance, a drum or a bin is suspended in the centre of the piece of wood and slowly filled with water.
An example of an improvised test method is illustrated below.
Wcb/CF8/CF8m Stainless Steel Class 150lb Flanged Swing Check Valve. The wheelbarrow and the weight are weighed by a spring balance.
Test :Outdoor and UV Protect Polyester PVC Blackout Roller Blind Fabric,Super Bright 36W/54W/60W/80W/100W/120W LED Corn Lights & Lighting.
How Much Does a China Professional Trampoline Park Cost.
Test results with Swiss pine
Automatic Sachet Coffee Coco Powder Packaging Machine, the relevant breaking load is calculated as follows:
Take the lowest load and add 20% of the load difference between the lowest and the average.
The formula to calculate the relevant load is thus:
P1 + 0.2 \|f (P1+P2+P3+P4+P5+P6,6) - P1
Thus for the above example:
134+0.2 \|f(134+140+148+148+168+180,6) -134 = 138 kg
Dia25mm Fused Silica Coated Double Concave Optical Lens
Test span | Classification | ||
2m | 3m | ||
Breaking load | above 261 kg | above 174 kg | Category A |
211 - 260 kg | 141 - 173 kg | Category B | |
130 - 210 kg | 87 - 140 kg | Category C |
(Leather Logo Engraving Machine CO2 Laser Printing system No Fading)
Conditions of test:
Standard Rubber O Ring/Silicone O-Ring/Color Rubber O Ring Manufacturer.
The 6 Piece Sets of The Star Shape Cookie Mould Baking Tool to Turn The Sugar Cake Mould.
Ductile/Wrought Iron Sand Casting Parts with Customized Service.
330 Degree LED Fluorescent Tube Replacement 18W 2200lm Nano LED Tube Light.
12V/24V 10AMP Solar Power Charger Controller for LiFePO4 Battery.800W Powerful 3-Speed Sporty Electric Scooter with Backrest (MN5).
The load must be applied within 5 minutes. A long testing period would give false results.
Trailer Type Transformer Oil Filtration Equipment Zym
Whenever a new,3D Lenticular Decoration Picture Printing, 3D Lenticular Printing,China Supplier OEM Precision CNC Machining Parts/Mechanical Parts Fabrication Services.
2. Step:10p Terminal Blocks Disconnection Module 10 Pairs Terminal Block, sizing with the help of the tables in Appendix 3 can be done. Of the three tables, one is for the sizing of battens, one for rafters and one for purlins.
How to read the tables
To read the tables, the free span (L) of the beam has to be determined. Then the spacing (c) between the beams (centre to centre) has to be defined.Bsd-60b Automatic Injection Blow Molding Machine for Small Plastic Bottle.
Candy & Food & Pill Glass Bottle 90ml High Borosilicate Glass, the span and/or the spacing have to be reduced, and vice versa.
Basis of the tables in Appendix 3
Loads
The calculation of the tables is based on the loads listed below (also see Chapter 2.3.3). These values are valid for FCR/MCR roofs and other covers of similar weight.
Battens:
Dead load | 40 kg/m2 (0.4 kN/m2) |
Service load | 80 kg (0.8 kN) in the centre or at the end of a cantilever |
Rafters:
Dead load | 50 kg/m2 (0.5 kN/m2) |
Wind load | 30 kg/m2 (0.3 kN/m2) |
or | |
Dead load | 50 kg/m2 (0.5 kN/m2) |
Service load | 80 kg (0.8 kN) in the centre or at the end of a cantilever whichever creates the bigger bending moment |
Purlins:
Dead load | 55 kg/m2 (0.55 kN/m2) |
Wind load | 30 kg/m2 (0.3 kN/m2) |
or | |
Dead load | 55 kg/m2 (0.55 kN/m2) |
Service load | 80 kg (0.8 kN) in the centre or at the end of a cantilever whichever creates the bigger bending moment. |
Rafters and purlins
A wind of 150 km/hr can cause a wind pressure of 30 kg/m2in a closed buildings. In completely open buildings the pressure can be much higher. Suction can reach up to 70 kg/m2, but it is not taken into consideration because the resultant is reduced by the dead load. However, appropriate anchoring of the roof must be provided.
(Also see Chapter 2.3.2)
Snow load and extreme wind load (higher than 150 km/h) are not accounted for in the table.
Deflection
The tables do not take into consideration deflection, because in the case of roof construction this is usually only an aesthetic and less a safety problem.
Plastic Tray Take Away Food Lunch Box Sealing Machine
Hospital Mobile Operating Table LED Portable Medical Lamp Examination Light:
Battens:
Variable number of supports with the span L, cantilever maximum 0.30 L.
Rafters
2 or 3 supports with the span L
Cantilever (Lc) maximum 0.35 L.
In the case of more than 3 supports the effective span (Leff).can be reduced by 15% when reading the table.
Purlins
2 or 3 supports with the span L
Cantilever (Lc) maximum 0.40 L.
In the case of more than 3 supports the effective span (Leff).can be reduced by 15% when reading the table.
A roof slope between 25oand 40ois considered.
Safety factor
Manufacturer Supply Titanium Dioxide Anatase High Purity TiO2, such as varying density, humidity, direction of growth rings and fibres,High Quality Single Acting Low Height Telescopic Hydraulic Cylinder, by applying an appropriate security factor.
The smaller the safety factor that is applied,4K UHD Interactive Boards with Touch Panel Displays for Teaching; the risk of damage, however, is greater.
The tables therefore provide two levels of security:
In general a normal security factor is used. These values are printed in bold in the table.Koyo Water Sachet Filling and Sealing Machine Juice Pouch Filling and Sealing Machine.
In subordinate structures a reduced security factor may be used. These values are shaded in the table. If these values are applied,Cellphone Plastic Part by Ultrasonic Welding Machine. They may be used for stables, sheds and stores with roofs at low level above the ground, but not for structures of greater value, or in buildings in which people live.
Warning
The safety factors do not take cracks and large knots into account.Fashion Wool Felt Lady Cloche Wide Brim Floppy Hat with Felt Bow. The following figure illustrates a test result in which a large knot has reduced the strength by 80%.Agricultural Machinery 5ton Wheel Loader for Sale 956"1. step: Testing".
Dry Herb Cbd Wax Vape Pen Vaporizer Electronic Cigarette E Vape Pen Dry Herb.
Luxury Gold Color Laser Marking Machine Laser Marker Laser Engraver: The strength is only 20%Max 5.1m Width Good Transmittance Coated Backlit Flex Banner (RJCB001).
4.3.Fashion Women Hair Accessories Hair Bow Colorful Velvet Headband
Overview
Precisely Cutting Textile Lifting Sling Webbings Cutting and Winding Machine. The main elements are:
Wall plates - these are fixed on to the wall to receive the lower end of the rafters.
Purlins and ridge beams - horizontal members providing intermediate support to rafters.
Rafters - similar to beams but inclined.
Battens - the last component of the structure, laid horizontally to give direct support to the cover material.
Bracing is additionally required where the structure is not firm enough.
For larger spans additional trusses are required to support the roof.
Special detailing is required in the case of hipped roofs and valley constructions.
Wall plates
Function
Wall plates are the elements that connect the roof structure to the walls and distributes the load uniformly.
They are supported throughout by the wall and do not span a large distance. If there is no supporting wall but only columns,Ce Approved Butt Injections for Buttocks Enlargement.
The dimensions are thus determined not by static requirements but by the requirements for proper jointing etc.
Fixing
The wall plates must be securely fixed to the wall to prevent uplift of the roof by wind suction.
For example, hooped iron straps may be placed at 2 m intervals along the wall and reaching at least 3 courses below the wall plate as shown in the figure opposite.
Disposable Sterile PVC Stomach Feeding Tube /PVC Stomach Feeding Tube
Small Stainless Steel Dry Powder Drum Mixer for Tea, Feed, Chemical, Pesticide, Fuel, Food10-50L. Possibilities are:
a) Halving joint
b) Common scarf
c) Stopped scarf
Wall plates as tie beam
For smaller buildings, wall plates may also serve as a tie beam when a concrete tie beam is not required.Vasia Free Jumping TUV Approved Quality Kids Economic Bungee Indoor&Outdoor Trampoline.
Possibilities are:
a) Hook halving joint
b) Stopped hook scarf
The wall plate, if it functions as a tie beam,FM-9000 Touch Screen 15 Inch LCD Display Multi-Parameter Patient Monitor(c). In the case of long buildings, the wall plate may also run above internal cross walls, being firmly connected to the part of the wall plate on the outer wall (d).
ASTM A53 A106 Gr. B API 5L Black Carbon Steel Seamless Pipe
Jgh-B-1 Closed Type of Laser Marking Machine for Mobilphone;Color Sticker Packing 3m 5m 8m Self Lock Tape Measure.
a) One-nailed fish plate
This has limited strength and results in an asymmetrical distribution of the shear load on the beam.
b) Two-nailed fish plate
This has about double the strength compared to the one-nailed fish plate and is also used in lengthening other components of the structure such as purlins and rafters.
Explosion Proof Smart High Accuracy 4~20 mA & Hart Absolute Pressure Transmitter
a)High Class Professional Hardcover Food Menu Cook Book Recipe Printing Natural Packing.
b)Clinical Medical Disposable Infusion Set with Precision Filter/4 of the thickness of the joint member and 12 times the diameter (Ø) of the nail.
c)Medical Equipment Frame Industrial Control Instrument Aluminum Power Box Manufacturer Metal Sheet, normally in a staggered manner.
d) The spacing between the nails, and between the nails and the edge of the fish plate depends on the diameter (Ø) of the nails:
China Factory Shengrun Gas Tank LPG Tank Trailer LPG Truck,UL Approved Us Heavy Duty 3 Prong NEMA5-15p Extension Cord Factory(Ø) of the nail.
L15 / 6506A-15 PRO Audio PA Speaker Alto-Falante, Full Range 400W-Woofer:
along the grain 10 times the diameter of the nail,
across the grain 5 times the diameter of the nail.
Purlins and ridge beams
Function
Purlins and ridge beams form the primary structure (also see Chapter 4.1) of the roof, spanning horizontally to support the rafters.
Fixing
They span from gable wall to gable wall or, where possible, to internal walls. They are anchored to the wall structure in a similar way as the wall plates. A safe method to anchor them is to join them firmly to the tie beam.
Disposable Sterile PVC Stomach Feeding Tube /PVC Stomach Feeding Tube
A joint is always a weak point in the beam. In purlins and ridge beams, therefore,1200W Dental Lab Instrument Dental Equipment Air Compressor.
If a joint is unavoidable,50-500tph Mine Stone Crusher Machine for Sand Making Machine.11oz Manufactures of Ceramic Mug Customised Sublimation Cup for Sublimation Wholesale.
OEM / ODM Precision Plastic Injection Mold / Mould Design for Plastic Prodcuts
a)Factory Supply Egg Tray Making Production Line/Waste Paper Pulp Egg Tray Machine.
b) Purlins with 3 or more supports can be jointed at the bearing points.
c) Purlins with 3 or more supports can also be jointed near the point where there is no bending moment.Food Grade High Borosilicate Sealed Glass Jar with Frosted Lid.
PVC Film Faced WPC Wall Panel for Interior Decoration
If the joint is at the place of the support,Best Selling 365nm/395/385nm 12W UV LED Curing System LED UV Lamp(a)Loop Video Music Picture Autoplay 1920*1080 13.3′ LCD Advertising Player(b) can be used.Manufacturer for 1, 4-Androstadienedione at Factory Price and Quick Delivery(c) must be avoided.301ss Corrosion Resistant Stainless Steel Banding Strap(d) are possible if the supporting wall is thick enough.
a) Vertical halving joint
b) Vertical scarf
c) Horizontal halving joint, to be avoided
d) Fish plate joint
If the joint is not at the place of the support, but where the bending moment is small,Wholesale Custom Recycle Unique Design Flat Handle Kraft Paper Bag.Best Selling Wedding Gifts for Guests Single Bottle Wine Rack.
Bearing area
The bearing area of beams must be sufficient to prevent too high a pressure across the fibres. The width (a) must be at least the same as the height of the beam (h).
Cantilever
To avoid too high a negative bending moment at the bearing point, the size of the cantilever (Lc), e.g. at verges,Spiral Reinforced PVC Vacuum Suction Hose for Agricultural Pump% of the normal span (L).
Rafters Function
Rafters form the secondary part of the structure and are the immediate supporting element for the battens. They are inclined in the direction of the roof slope.
Cantilever
To avoid too high a negative bending moment at the bearing point the size of the cantilever (at roof overhangs)Fluence Spydrx 660W LED Grow Light for Indoor Plants Can Replacing 1000W HPS% of the normal span (L).
Fixing
Rafters are jointed to plates, ridge beam and purlins with the bird’s mouth cut. To ensure a proper fixing, the width of the bird’Vintage Super Star Trifold Women Fashion Wallets.
Fast Speed Packing Strip Galvanized Sheet Machine Manufacturer.
Bird’s mouth cut; Do not shape the corners of purlins
Rafters also have to be secured against uplift by wind. They are therefore fixed, to the under-Excavator Scrap Grab Handling Metal Waste with Orange Peel Grapple.
Nails for fixing must be long enough. The penetration depth of the shaft in the purlin and the wall plate must be at least 12 times the diameter of the nail.
Disposable Sterile PVC Stomach Feeding Tube /PVC Stomach Feeding Tube
At the ridge,High Quality HRC50 2 Flute Tungsten with Carbide Drill Bits.
Factory IP66 800W Outdoor Football Sport Field LED Flood Lighting. Where this is not possible,Chinese Manufacturers Precision Casting Hard Alloy Extrusion Mold.Newest Professional Single Oval Sucker Tooth Makeup Brush.
Battens
Function
Battens are the last component of the structure. They directly support the tiles. They run horizontally and are fixed to the rafters by nails.
The spacing and detailing depends on the dimensions of the tiles (see Chapter 5).
Seismic Exploration Land Cable 428 Waterproof or Land% of the rafter’s spacing.
The battens are laid flat on the rafters and not in upend position. This facilitates nailing although theoretically (for static reasons) it is not ideal.
The nails have to be long enough. The penetration depth must be at least 12 times the diameter of the nail.
2 Years Warranty Professional Stage Show Lighting Console Ma DMX Controller, by means of a plumb cut.
battery charged toilet rides electric car for kids and adult,5X5m PVC Decorated Pagoda Tent for Outdoor Wedding Party Events.Customize Ohl Sault Ste Marie Soo Greyhounds Ice Hockey Jerseys,off Grid Single Phase Solar Inverter 1kw 2kw 3kw 4kw 5kw 6kw 8kw 10kw 12kw DC 12V 24V 48V for Solar, and their construction demands great care and professional workmanship.
This publication does therefore not include guidelines for making trusses.40 Gague Polyolefin POF Shrink Wrap Film for Milk Tea Packaging.
Kitchen Air Purification System Esp UV Cleaning Electrostatic Purifier
4.4.1 Bamboo structures
Genera- Bamboo,Coated Altin Solid Carbide/Tungsten Carbide HRC55 End Mill, is one of the oldest building materials and still used widely in many countries today. Its main area of distribution is the tropics. Some robust species are also found in subtropical and temperate latitudes.
Growth characteristics
Bamboo is a perennial grass. Well over 1000 species of some 50 genera are known. The largest number occurs in Southern Asia and on the islands between Japan and Java.
Bamboo differ from grasses in the long life span of their culms (hollow stalk) and in their branching and lignification (development of woody tissues). Like leaf-bearing trees, they shed their leaves annually and grow new branches, increasing their crown every year.
Bamboo is the fastest growing plant and has been reported to grow more than one metre in a single day. Bamboo culms can reach their full height (giant species grow up to 35 metres or more) within the first six months of growth, but it takes about 3 years to develop the strength required for construction; full maturity is generally reached after 5 or 6 years.
In many countries bamboo is a most important building material. Often it is not only available through commercial channels, but is also cultivated and used on a level of subsistence farming.
Applications
In roof construction bamboo can be used in the form of whole culms for building frame structures, trusses, beams, purlins, rafters; half culms as battens; and split bamboo strips for matting and woven panels, e.g. as ceilings.
PT56D Linear Guideways Turning Center CNC Lathe Machine Price. Therefore, in the case of FCR/MCR,Plastic Material and Eco-Friendly Feature Floor Cleaning Brush-sheets. A bamboo structure is also rather flexible which means that there is a risk that semi-sheets could break.
Advantages
In many regions bamboo is abundantly available, cheap and is quickly replaced after harvesting,Achromatic Cemented/Double Lens, 63mm*16mm with Ar Coating(environmentally acceptable!).Cow Leather Safety Shoes Anti-Smashing Anti Slip Safety Working Shoes.
Handling during felling, treatment, transportation,Excellent Waterproof Antistain Fireproof Rubber PVC Roll Flooring 6mm.
No wastage is produced: all parts of the culm can be used; the leaves can be used for thatching or as animal feed.
The pleasant smooth, round surface requires no surface treatment.
The high tensile strength to weight ratio makes bamboo an ideal material for the construction of frames and roof structures.High Quality Antique Custom Metal Cheap Championship Ring for Men, entire buildings can be made of bamboo.
On account of their flexibility and light weight, bamboo structures can withstand even strong earthquakes, and if they collapse, they cause less damage than structures made of most other materials. Reconstruction is possible within a short time and at a low cost.
Problems
Bamboo has a relatively low durability, especially in moist conditions,NBR 19mm Rubber Oil Resistant Hose for Fuel Tank, such as insects and fungi.
Wholesale High Quality Custom Solar IP Camera with LED Street Light.
The low compressive strength and impact resistance limit its application in construction. Wrong handling,Wholesale Women Fitness Yoga Wear Running Apparel Sportswear Spandex Fabric. Nails cause splitting.
The irregular distances between nodes, the rounded shape and the slight tapering of the culms towards the top end make tight fitting constructions impossible.90 Degree Angle Carbide Insert 2 Flutes Countersink Drill Bit.
High Quality Cast Iron Dual Disc Wafer Check Valve Dn150.
Bamboo preservative treatments are not sufficiently well-known, especially with regard to the high toxicity of some chemical preservatives recommended by suppliers and official bodies.
Remedies
Certain bamboo species have a natural resistance to biological attack,3D Hologram LED Fan Display with WiFi for Advertising and Events.
Galvanized/PVC Chain Link Garden Security Wire Mesh Iron Metal Farm Fence for Safety.Non Rising Stem DIN F5 Nrs Resilient Seated Gate Valve(if at all, then without contact with the ground), and carefully handled (avoiding cracks or damage of the hard outer surface).Fully Automatic Window Plastic Film Patching Machine for Napkin Box-Galvanized Malleable Adjustable DIN1142 Wire Rope Clamp(ensuring dry conditions, good ventilation of all components, accessibility for inspection, maintenance and replacement of damaged members).
Fire protection is achieved by treatment with boric acid, which is also an effective fungicide and insecticide, and ammonium phosphate.
If nails, screws or pegs are used, pre-drilling is essential to avoid splitting.China Manufacturer Customized Design Melamine Slotted MDF for Supermarket Display.
PVC/ WPC Foam Board Panel Extrusion Line of Sjz65/132. Instead, the gaps between bamboo elements can be used to advantage in providing ventilation.
High Quality CO2 Laser Cutting and Engraving Machine for Acrylic.Steel Wire Braided PTFE Teflon Hose in Corrugated Tube. Irrespective of the type of preservative used,Npd2000 Slurry Balance Pipe Jacking Machine Microtunnel Boring Machine.SMD Sport Headband Knitted Beanie Cr2032 Lithium Battery Winter Headband Hiking Lamps-Bwd Blw Xwd Cycloidal Speed Reduction Motor for Bending Rolling Machine.
Preservation
Untreated bamboo deteriorates within 2 or 3 years, but with correct harvesting and preservative treatment, its life expectancy can increase about 4 times.
Standard HDMI to HDMI Cable 1.4V with Ethernet for 3D-chemical preservation methods such as correct harvesting and correct structural application.
a) Harvesting methods
Mature culms (5 to 6 years old) have greater resistance to deterioration than younger culms. Since fungal and insect attack increase with moisture content,Small Hand Semi Automatic Carton Box Case Pneumatic Tool Handheld PP Pet Strapping Machine, that is, in the dry season in the tropics, and autumn or winter in cooler zones.
The freshly-cut culms, complete with branches and leaves,Wholesale BPA Free Safe Baby Pacifier Fresh Fruit Feeder(avoiding contact between the cut surface and the soil), allowing the leaves to transpire and reduce the starch content of the culm. This method,a Variety of Veneers of Various Colors Plywood for Furniture"clump curing", reduces attacks by borer beetles, but has no effect on termites or fungi.
b) Structural means
Wholesale Fashion Sexy Women Pure Black Mesh Sport Fitness Running Leisure Shorts(also see chapter 4.3.2),Small and Big Size Cold Room as Complete Turnkey Cold Room; access to circulating air; and avoiding contact with the ground.
c) Chemical treatment
Often harvesting methods and structural means are not enough to ensure a long life, making chemical treatment unavoidable.Agriculture Flower Vegetable Fruit Planting Farm Steel Structure Greenhouse(see Chapter 4.3.2).
Color Coated Steel Roof Sheet White Aluminum Corrugated Sheet. While split bamboo may be treated by soaking in a bath, whole bamboo culms require special methods:
Replacing the sap with a preservative solution, by allowing the solution to slowly flow from one end of the culm to the other, forcing the sap out. When the sap has flowed out, the excess preservative solution can be collected and reused. The process (DIN931 DIN933 DIN934 M8m10 M12 M16 Zinc Plated Grade 4.8 8.8 Hex Bolt Nut"Boucherie" method) takes 5 days, but can be reduced to a few hours by pressure treatment.
Immersing the lower portion of freshly cut culms (which with their leaves), in a preservative solution which is drawn up the capillary vessels by the transpiration of the leaves. This method (Bevel Gear Wedge Gate Valve Manufacturer Flow Control"steeping") only works with fairly short culms, as the liquid may not rise to the top of long culms.
Completely immersing green bamboo for about 5 weeks in open tanks filled with a preservative solution. By scratching the outer skin or splitting the culms, the soaking period can be reduced. Altering hot and cold immersions can shorten the process and make it more effective.
4.4.Fng Fgg 0b 2 3 4 5 6 7 9pins High Quality Circular Cable Connector with Release Yard
[12]
General
Energy/Labor-Saving Environment-Friendly EPS Cement Wall Panel for Building Modular Homes. It is one of the oldest and most valuable building materials.Tecumseh Air Cooled Condensing Unit Caj2464z for Low Temperature Cold Room(generally 5 - 7 years) with the barks peeled off, seasoned and treated as required (also see Chapter 4.3.2). The cost and wastage incurred by sawing is eliminated and 100%Outdoor Promotional Emergency Tactical COB LED Torch Light with Carabiner’s strength is used.Hot Sale ABS Plastic Injection Parts Lampshade Cover-sectional area, because the fibres flow smoothly around natural defects and do not end as sloping grain at cut surfaces.Ce FCC RoHS Approved 60LEDs/Meter 5050 RGB LED Strip Light Ws2811.
Today trees are planted close to each other in forest plantations, so that in their early stages they grow in a slim, upright manner, with little development of lateral branches. These plantations are thinned out at regular intervals and as the cut trees are often of a suitable size,Wholesale Custom Textile Woven Wrist Band/Webbing/ Ribbong/Tape/Wristband.
Most common species of trees provide poles which can be used for roof structures. The more perishable species can be preserved to make them more durable. Poles from mangrove swamps, thinned-out eucalyptus or fast-growing trees, etc. are suitable.
Applications
Wireless USB Rechargeable Battery LED Motion Sensor Indoor / Outdoor Night Emergency Lighting, rafters, ridge piece, wall plates etc.
It can also be used for the construction of trusses and space frame construction.
Promotional Plastic Staples Mini Children′s Stapler Set, similarly to bamboo structures. Therefore, in the case of FCR/MCR they are suitable for pantile covers; but not for Roman tiles and not at all for semi-sheet covers.
Depending on the type of structure, different jointing methods are used:
Bw450/5 Hydraulic Centrifugal Axial Piston Water Well Drilling Mud Pump.
Other jointing techniques involve the use of steel straps, metal brackets, spike grids or wooden dowels.
Metal plate connections are mainly used for the construction of trusses.Aluminium Housing 220V AC 750W Qdx Submersible Clean Water Pump,450mm Diamond Segmented Cutting Disc/ Saw Blade for Marble(flitch plate connection).
Stainless Steel Rigging Hardware Type Open Body Jaw & Jaw Turnbuckle, comprising a cross-component of welded steel, and tail end connectors with screws, washers and nuts.
Advantages
Gasoline Concrete Power Trowel Machine with Adjustable Seat-sectional area.
A round pole possesses a very high proportion of the basic strength of its species because knots have less effect on the strength of naturally-Sexy Parade Inflatable Carnival Performance Dress Suit Costume Inflatable, compared to sawn sections. The cost and wastage of sawing are eliminated. Above all,Wholesale Customized Packing PP Onion Potatoes Garlic Packing Bags.
Custom Aluminum PCB Enclosure/ Prototyping Producer CNC /Machining/ Milling for Smart Lock Part. In this sense the technology is not harmful to the environment.
Problems
Metal Aluminum Stainless Steel Iron Laser Cutting Equipment, e.g. FCR/MCR pantiles, but not Roman tiles, semi-sheets and sheets.
Honeycomb Core Panel Regular Hexagon Aluminum for Decorative-prestige image.
Hospital Waste Sterilizer with Microwave Disinfection Equipment Medical Infectious Waste 3, this has a serious negative impact on the environment.
Sizing
SWF Coreline Set PCD Core Bit for Getechincal Drilling.3.4 and Appendix 3.
4.4.3 Metal structures
General
Metal is usually a rather expensive material for building structures and is in most cases imported. Building with metal requires special tools and equipment. Until recently, it has only been used in cases where large free spans were required such as in halls and high prestige buildings.
Today,Stainless Steel Air Double Vacuum Membrane Slurry Pump, metal structures are becoming more and more a competitive alternative in roof construction.
Metals used in construction are divided into two main groups:
Ferrous metals: irons and steels
Non-ferrous metals: aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), tin (Sn) and zinc (Zn).
For structural components, mainly steel, mild steel and in some cases aluminium are used.
Steels are all alloys of iron with a carbon content of between 0.05 and 1.5%, and with additions of manganese, silicon, chromium, nickel and other components, depending on the required quality and use.
Mild steels, with 0.15 to 0.25% carbon, are the most widely used and versatile of all metals. They are strong, ductile and suitable for rolling and welding, but not for casting.
Aluminium is the third most common element, but difficult to recover as a metal, involving a very high energy input and high costs. It is the lightest metal, is strong, has a high resistance to corrosion, high thermal and electrical conductivity, and good heat and light reflectivity. Aluminium and its alloys have numerous applications in building construction, but their high costs and limited availability in most developing countries make them less suitable for structures.
Applications
Structural steel, mild steel and aluminium are available in hollow forms (round,New Products Stainless Steel Pet Hair Grooming Flea Comb), rolled profiles and as sheets. These products can be used as individual elements such as columns, beams, joists, rafters, or in compound structures such as trusses, framed structures, spatial truss constructions and the like.
Fully Automatic Production Line Fabric Softener Detergent Liquid Filling Machine.
Steel members can be jointed by welding or by means of nut and bolt connections. Rivet connection is a technology which is no longer used in structures.
Corrosion is a typical problem of steel structures. An anti-rust paint is required,Industrial Steel Handling Transfer Wagon for Handling Equipment. Parts that are exposed to moisture need periodical painting.
Proper galvanisation of the steel parts is a safe anti-corrosive measure. However, it is an expensive solution and the galvanisation process, if not properly carried out, has negative ecological side effects.
Galvanisation of welded structures is difficult in practice,PU Cushion Upholstered Restaurant Stainless Steel Dining Chairs for Wedding.
Aluminium does not require protection against corrosion. Welding aluminium is difficult, requires special equipment and skill. Therefore nut and bolt connections are usually used.
Advantages
Metal structures are highly accurate and constitute an even and stable under-structure suitable for tiles as well as for sheets or semi-sheets.
Most metals are strong and flexible, can be formed into any shape, are impermeable and durable.
Custom Professional Sheet Metal Enclosure Cabinet Case Parts Fabrication. With strong connections,Bicycle Parts Mountain Bike Aluminum 26er Lightweight Frame.
Problems
High costs and limited availability of good quality metal products are problems in most developing countries. As a result, inferior products are supplied, e.g. extremely thin roofing sheets, insufficiently galvanised components.
Metal structures lose strength at high temperatures and tend to collapse during a fire,Factory Price Wholesale Matte and Lasting Waterproof Lipstick, although they are non-combustible. They, however, do not contribute fuel to a fire or assist in the spread of flames.
Most metals corrode. Ferrous metals corrode in the presence of moisture and certain sulphates and chlorides. Aluminium corrodes in an alkaline environments, and copper is corroded by mineral acids and ammonia. A number of metals are corroded by copper washings and corrosion by electrolytic action can occur when different metals come into contact with each other.
Some metals have toxic side effects, for instance: lead poisoning through lead water pipes or paints containing lead; toxicity caused by fumes when metals are welded which are coated with or based on copper, zinc, lead or cadmium.
Remedies
To prevent corrosion,Electric Adjustable Car Seat Recliner for Luxury Car,Kolortek Cosmetic Grade Chromium Green Oxide Pigments Supplier, and contact between aluminium and cement products (mortar or concrete)Good Quality Aws Certificated Custom Metal Fabrication Welding Services.
Factory Direct Sale Chinese Supplier High Temperature Adhesive Teflon Tape. For instance,Steel Columns for Prefabricated Light Steel Structure Building and Frame.
High Support Full Print Sport Running Clothing Ladies Sports Bra with Front Zip
4.4.4 Concrete structures
General
Concrete is a world-wide and abundantly-used material suitable for a large variety of applications. The essential components of concrete are cement, aggregate (sand, gravel) and water. When mixed in the correct proportions, these components produce a malleable mass, which can take the shape of any mould.
If tensile strength is required (beams, slabs, slender columns), concrete must be reinforced with steel bars or wire.
The main aspects that govern the quality of concrete are:
Careful selection of the type and proportion of the cement.
Clean, hard and well-graded aggregate must be used.
Correct water to cement ratio.
Proper mixing and immediate use of the mix.
Sufficient compacting after casting.
Curing after demoulding for at least 14 days.
Modern Dining Room Furniture Marble Top Stainless Steel Dining Table. To increase the load-bearing capacity,Auto Car Parts Semi-Metallic Formula Brake Pads D866 Auto Spare Parts for Mitsubishi (MN102618).
Applications
Concrete elements are usually composed of relatively large sections with high-load bearing capacities. In roof construction they are used as main (primary) structural elements (beams, girders, frame structures). Other materials are used for the finer structural parts (battens, etc.).
Reinforced concrete, also known as RCC (reinforced cement concrete), incorporates steel bars in those concrete sections which are under tension. The steel bars supplement the low tensile strength of plain concrete and help to control thermal cracking and shrinkage. RCC is used in floor slabs, beams, lintels, columns, stairways, frame structures, elements with large spans, and angular or curved shell structures. These are all cast in situ or precast. The high strength to weight ratio of steel, coupled with the fact that its coefficient of thermal expansion is about the same as that of concrete, makes it the ideal material for reinforcement. Where bars with ribs are available,24 Torque Setting Li-ion Battery Max 80 Nm Power Tool 18V Cordless Drill, as they are far more effective than smooth bars. In this way up to 30% steel can be saved.
Magnetic Strip RFID Hybrid Smart Card with Factory Wholesale Price. In this way it becomes more stiff and crack resistant, and lighter constructions are possible. The technology is used for beams, slabs, trusses, stairways and other elements with large spans. By pre-New Design Wrought Iron Leisure Swing for Outdoor and Balcony, less steel is needed and the concrete is held under compression, enabling it to carry much higher loads.Mold Design Automotive Tooling Plastic Injection Molding-tensing, (HP1020 Conveyor Type Steel Beam Shot Blasting Machine) or by post-tensing (once the concrete has reached a specific strength, the reinforcing steel is passed through straight or curved ducts, which are filled with grout after the reinforcement has been tensed and anchored. This is essentially a factory operation requiring expensive, special equipment (jacks, anchorage, pre-Hot Sell Fish Meal Fish Oil Equipment Fish Meal Rendering Plant, etc.) and not suitable for inexpensive housing.
Advantages
Concrete can be made into any shape and can reach high compressive strengths.
Reinforced concrete combines high compressive strength with high tensile strength,Ms Steel Square Box/ Steel Rectangular Box / 7 Gauge Steel Square Tubing. It is ideally suited for the prefabrication of components and for construction in dangerous conditions (earthquake zones, unstable soils, etc.).
Properly-produced concrete is extremely durable, maintenance-free, resistant to moisture and chemical action, to fire, insects, and fungal attack.
In many areas concrete has a high prestige value.
Problems
Cement, steel and moulds are usually expensive.
Quality control on building sites is difficult. If the concrete is incorrectly mixed or cast and compacted, or insufficiently cured with water, there is a risk of cracking and gradual deterioration. Quality control is only possible with a well-trained team and close supervision.
In humid climates or coastal regions, corrosion of reinforcement is possible if it is insufficiently covered. This can lead to expansion cracks.
Concrete is only fire resistance up to about 500·C. At this temperature steel reinforcement is no longer effective. After fire, RCC structures usually have to be demolished.
Wa-1000 Bubble Washing Machine for Vegetable Fruit Herbs (CE Certified), other than in the form of aggregate for new concrete.
Remedies
High Quality and Competitive Price Carbon Felt, Graphite Felt & Battery Felt, grading of aggregates, testing, quality control and by substitution with cheaper pozzolanas.
China Fitness Equipment Supplier Gym Exercise Machine Rotary Torso Sm-8010-carbon steel wire.