Get Smart with Decks

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H3 Treated SmartLVL15 for Decks

Decks have become synonymous with the Australian lifestyle.  There’s nothing better than a gorgeous yard, complete with a great atmosphere and entertainment area to transform a house into a home.  So if you’re looking to add this great Australian icon to a home, make sure you do it the Smart way.  One of the biggest problems with decks is the risk of decay and rot; so why not start with a material that addresses this straight up?  Strong, durable H3 treated SmartLVL15 is ideal to use for bearers and joists in decking.

H3 treatment provides protection against decay and termites in timber.  As an Engineered Wood Product, SmartLVL15 gives builders a straight and consistent sized product to work with, without the issues of shrinkage after installation.  With continuous lengths of up to 12 metres, SmartLVL15 provides whatever length is needed for the job, while its superior strength means longer spans and less piers.

To get the most out of H3 treated SmartLVL15 for deck applications, there are some points to remember:

  • Ensure construction detailing prevents water entrapment.
    Water being trapped and pooling due to poor building practice will cause deterioration of timber, no matter what its durability or treatment level.  Well detailed timber construction that conducts water away from the timber is best to ensure great appearance and structural performance for many years.  Good construction detailing is needed in conjunction with H3 treatment, resealing, painting and capping.
  • Keep your timber structure 150mm above the ground
    Providing that termite inspection is not required, there is adequate ventilation and it does not contravene any Local Government requirements, it is acceptable to reduce the ground clearance of SmartFrame product to the 150 mm minimum shown in table of the BCA.
  • Always reseal the ends when cutting H3 treated SmartLVL.
    During installation all SmartFrame® H3 LVL must be thoroughly resealed with application of a suitable in-can wood preservative such as Tanalised® Enseal on all surfaces exposed by cutting to length, notching, drilling or similar operations.
  • Use the right fixings
    Use corrosion resistant nails, plates and fixings for all exterior timber work.
  • Paint your installed H3 treated SmartLVL.
    SmartFrame recommends painting all H3 treated SmartLVL 15 as best practice for exterior deck applications.  Talk to your NHS representative about quality paints.
  • Always use a protective membrane above H3 SmartLVL joists.
    Installing a high density waterproof cover or malthoid capping over joists helps with water runoff to avoid pooling, while effectively sealing around nails.  Protectadeck™ is available at NHS and assists with the life of decks.
  • Use the right joist spacings for your choice of decking
    The maximum joist spacing for decking is 500 mm centres for 19 mm Hardwood, and 400 or 450 mm centres for 19 mm or 22 mm Treated softwood respectively (AS 1684.2—2010). Decking must be fixed to H3 treated SmartLVL 15 deck joists with skewed nailing, self-drilling screws or concealed fixing systems from below as shown in the SmartLVL Design Guide.


NHS is a preferred reseller of Tilling SmartLVL15.  NHS customers can always be confident of high quality and performance warrantied job lots of SmartLVL15 H3 delivered in full, on time.  The Tilling Smartphone App has a span calculator to assist with bearer and joist sizes.  Comprehensive design and/or installation guides are available on their website, and a technical help line 1800 668 690 also can assist with any questions you may have.

To build a smarter deck, or any larger structure, talk to your NHS representative about SmartLVL15 H3, or visit