Send To A Friend The Garden Builders, as a rule, build decking in the following way. Of course, this may alter according to each particular project? On the whole, this method is the tried and tested method and conforms to current construction standards. The most important part of the decking is the framework on which the decking sits.
The framework consists of the following sections:-
These are the main supports for the decking and will absorb all the load bearing from the decking boards laid above. Treated posts 100mm x 100mm (4”) are fully concreted into the ground and cut to the required height and sealed at the cut surface with Endseal or another suitable preservative in order to seal the cut surface. In some situations the posts are not necessary; roof terraces and over hard surfaces. In these cases the joists will sit directly on to plastic packers, or similar method, to allow for air circulation.
The beams of a deck are the intermediate structural members. They transfer the dead loads of the joists. As a rule the Garden Builders use 100mm x 100mm (4”) treated softwood timber, which rests directly onto the posts. This is most important as it is vital to transfer the load to the support posts, which provide the best compressive resistance. The most common fixings used are galvanised nails or protected coated bolts.
Joists are normally 100mm x 50mm (4” x 2”), fully treated softwood timber. The decking boards rest on the joists and the joists transfer weight to the beams and posts. The spacing of the joists depends on the span capability, which in turn is determined by the dimension of the decked area. Typical joist spacing methods range from 450mm – 600mm (24” joists). Joists are fixed to the beams using galvanised 100mm (4”) nails or stainless steel screws.
Decking (deck boards) – the actual upper surface which is visible, comes in a variety of different timbers both hard and soft woods (see timber list) and sizes. Decking provides an attractive and versatile surface suited for general use ie. walking and standing on. Deck boards are available in various widths such as 19mm x 95mm and 145mm x 21mm. Different widths and sizes are subject to the clients and designer’s specification and requirements. Deck board profiles are usually a smooth pencil round finish. Grooved deck boards are available but are used far less due to the ridged appearance. Sometimes clients ask for the grooved decking as it is believed to be slip resistant but we have not found this to be the case. The majority of decking is fixed into place using stainless steel screws. When installing a hard wood deck our usual practice is to pre-drill the area, prior to fixing with screws, to avoid possible splitting of the decking. Galvanised lost head ring shank nails can be used on softwood timber, subject to specification. All deck boards should have a slight gap between them to allow for natural expansion, usually 2-3mm.
We always install a geo textile membrane where a deck is mounted over open ground to prevent the growth of perennial weeds through the subframe. A typical product would be Terran or something similar.