Your Deck Master knows that satisfying you, the customer - by delivering improved decking performance over a longer life, through exceptional service and quality materials, workmanship and building techniques -  is why he or she is in business.

Quality in materials and construction are the most important aspects of decking delivery as these elements determine whether a deck will perform well over a long life when exposed to the damaging effects of weathering.

The Building Code of Australia (BCA) contains technical provisions for the design and construction of buildings and other structures, covering such matters as structure, fire resistance, access and egress, services and equipment, and certain aspects of health and amenity.  The BCA has the status of building regulations in all States and Territories, providing the minimum regulatory requirements for buildings in Australia.  Your decking project must, as a minimum, comply with the BCA.  In addition to the requirements of the BCA there are many good practices in material selection and construction techniques which are appropriate to deliver a satisfying decking project which gives good performance over a long life. 

Following are the important individual elements in the construction of a deck.  Although we believe that these elements combine the best practices from the BCA and from experience in decking materials and construction, if there is any discrepancy between these elements and the requirements of the BCA, the BCA shall take precedence.  Similarly, if any element is not addressed eg termite management or handrail design and construction the requirements of the BCA shall be complied with.

In addition to the requirements of the BCA, it is strongly recommended that the deck builder, specialist contractor or customer (as appropriate) apply the following good practices:

• Design in timber with suitable properties for long term performance.

• Timber of any stress grade can be made to perform the structural task of supporting the design load with the timber sections specified to an appropriate size, however not all timber has suitable properties for long term performance in the weather.  Specifying in a higher stress grade timber (eg F14) will not guarantee appropriate properties.  To ensure good performance specify the properties required:

• (high durability - durability 2 or 1 depending on conditions

•  low shrinkage (<8% tangential shrinkage or seasoned)

• Alternatively specify species with suitable properties
  (See  Suitable Structural Timbers for the Decking Subframe for more detail)

• Use wide joists - 50mm unseasoned, 45mm seasoned  

• Use good quality decking timber (seasoned, stable and of high durability)

• Use a moisture barrier between bearer/joist and joist/decking surfaces

• Use hot-dipped galvanised or stainless steel fixings as required by the BCA and suitable for the exposure conditions. 

• In highly corrosive environments such as in coastal areas and around pools, all post supports, brackets and fixings (including nails, bolts, concrete anchors, screws and connector nails), shall be stainless steel.

• Protect decking from heat and moisture while stored on site prior to use

• Provide suitable drainage and grading of the area under the deck, to ensure water runs away freely and the area under the deck dries quickly after rain, without water pooling

• Use good workmanship (including measuring carefully, cutting square)

• Seal checked joints and timber interfaces of subframe timber and handrail components with an appropriate sealer before construction.

• Apply a finish/sealer liberally to the cut ends of decking before fixing

• Allow a 3 to 5mm gap between adjacent decking boards (depending on the gap required eg for rewquired appearance or for bushfire requirements (AS3969 Bushfire Zone) after any shrinkage occurs, the moisture content of the decking as supplied and ambient moisture content which the decking moisture will move towards over time).  With the number of variables any calculated gap will only be approximate.

• Stagger butt joints so they do not occur on adjacent boards

• Fix decking with stainless steel screws or by hand nailing with stainless steel or hot dipped galvanised twist shank domed head nails.

• Hand nailing will give a stronger hold down than machine nailing but takes longer and will be a more expensive option

• Galvanised bullet heads can be an effective fixing into hardwood joists in weather protected conditions

• Machine nailing with stainless steel nails may be effective into hardwood joists depending on the timber used for the joists and type of nail used.  Generally, nails with a coarser pitch (threads further apart) will be more likely to be effective into hardwood joists as this will allow the nail to screw in when subjected to high driving force from a nail gun).  Machine nails manufactured for fixing into softwood joists are ring or annular shank type.  If wanting to use gun nails to fix decking, refer to your supplier of machine nails for recommendations as to suitability.

• Place nails in a formal staggered alignment to avoid splitting the joist

• Drill a small pilot hole in the decking to avoid splitting

• At butt joints:

• if using nails for fixing, drill the board ends to approximately 80% of the nail diameter and hand nail to avoid end splits (test on off-cuts)

• nails at board ends may have to be skewed slightly inwards to achieve the necessary clearance to the end of the decking board and edge of the joist.

• adjacent nails at board ends should be driven at slightly different angles to reduce the potential for splits to form between the nails.

• Drive nails so that the head is flush with the top of the decking - do not punch into the decking

• Apply another finish coat after the decking has been laid (where a penetrating oil or stain finish is to be used) or as recommended by the manufacturer

• Reapply the decking finish at regular intervals as recommended by the finish manufacturer

• Undertake a termite inspection at regular intervals as recommended by pest treatment professionals in your state

To achieve best long term performance, the following practices should also be undertaken:

• Seal the tops of joists before fixing decking

• Apply one sealer coat all round the decking boards before fixing (where a penetrating oil or stain finish is to be used) or as recommended by the manufacturer,  to protect decking from weathering

• Cut deck board butt ends with a slight backward undercut

• Seal cut ends of deck boards before fixing

Although the good practices above are detailed, there are few additional activities required to build a good deck than to build a poor deck.  It is simply a matter of using the right materials and practices in each situation.

The recommended construction practices are outlined in greater detail in the following documents available as downloadable copies:

Please note that the recommendations contained in the Construction Standard are not mandatory or automatically applied in their entirety by your local Deck Master who may have access to suitable alternative materials and may have developed alternative techniques which have been found to be effective and efficient. It is suggested that you gain an overall understanding of the materials and construction issues from the Construction Standard and then discuss your requirements for your project with your local Deck Master, with reference to the Construction Standard, and if you require or prefer that specific materials or techniques be incorporated into your project eg hand nailing for improved and longer lasting fixing, that you discuss your requirements with your local Deck Master and come to a suitable agreement.

Deck Master Construction Standard - (click here for a downloadable copy),
with additional explanation in the

Deck Master Construction Standard Explanatory Notes (click here for a downloadable copy).