Vault Decking FAQs

  • What is PERMADECK™ Vault?

    Vault decking is a giant leap forward in a wood alternative decking. The EovationsTM
    process starts with a mixture of polypropylene and calcium carbonate that’s pull
    extruded for cavitation. Cavitation creates tiny air pockets that keep the boards
    lightweight, but with a fibre-like structure similar to wood, giving it unmatched

    In addition, there are no organic materials to absorb moisture making it 100%
    waterproof, it’s unaffected by the sun, it’s microbe-resistant and has the lowest
    expansion/contraction rate of any composite decking product on the market.

  • Does the environment benefit?

    Yes. When PERMADECK™ Vault reaches the end of its life span it CAN be recycled meaning it won’t end up in landfill.

  • Does it fade to a tired old colour?

    No. PERMADECK™ Vault does not fade and does not require painting or staining to retain its colour. It will not change colour or become tired like wood.

  • How big is the gap between the deck boards?

    Using the Hidden Fastening System the gap is automatically set at 5mm.

  • What is the recommended spanning distance between joists?

    400mm Joist centres are recommended. Maximum Joist centres of 450mm can be used but MUST NOT exceed this distance. Exceeding 450mm will void warranty. Laying boards diagonally across Joists requires Joist centres to be spaced at 300mm.

  • How do I fix it?

    PERMADECK™ Vault uses a unique Hidden Fastening System so there are no visible screws or nails protruding from the board.

    You can if you wish, top-screw PERMADECK™ Vault and not use the Hidden Fastening System. We recommend using a flat head counter sink screw for fixing. While pre-drilling is not necessary it is highly recommended to reduce the risk of any “mushrooming” around the screw heads.

  • How much will PERMADECK Vault expand or contract?

    The rate of expansion/contraction for PERMADECK™ Vault is 0.5mm per metre lengthwise. This equates to just 3mm over a 5.8 meter decking board, this is the smallest expansion/contraction rate on the market today. Expansion and contraction through the width and depth is so minimal it will have no noticeable effect.

  • Where can I use PERMADECK™ Vault?

    Anywhere you would previously have used decking timber (subject to Local Government Regulations and Council approval if required) – such as decks, around pools and spas, marinas and pontoons, boardwalks, school play areas, etc. The waterproof and rot proof properties make it especially ideal for wet areas.

  • Can this product be used for marinas?

    With one of the highest slip resistant scores on the market, PERMADECK™ Vault is ideal for applications on marinas, boardwalks, etc. With the unique Hidden Fastener System, the decking has the ability to flex and prevents the boards from warping, splitting or tearing away. Vault is ideal for use around swimming pools and spas.

  • What is the moisture resistance of PERMADECK™ Vault?

    PERMADECK™ Vault is 100% waterproof and can be submerged 24/7
    There are no organic materials like wood fibre for example to absorb moisture.
    Moisture absorption according to ASTM D 1037 Standard Test Method is <0.4%5

  • Does PERMADECK™ Vault need ventilation?

    Yes, even though PERMADECK™ Vault can be installed in or in contact with the ground or water, providing adequate ventilation will allow PERMADECK™ Vault and the underlying ground to dry, this will also allow rain water to drain away easily.
    PERMADECK™ Vault is mould resistant, however without sufficient ventilation or in
    areas where organic debris can collect and does not get washed off, mould may

  • Will it warp?

    Most warping in timber is related to moisture absorption. PERMADECK™ Vault is 100% water proof & will not warp provided it is used and fixed in line with fixing instructions.

  • Does it splinter?

    No. This is an ideal surface for bare feet and small children.

  • Does it mark easily?

    No. The surface of  PERMADECK™ Vault is scratch resistant & will also conceal minor scratches. Avoid dragging furniture or heavy items across your deck as this may gouge the deck surface. We recommend that protective mats or furniture pads are used to protect against high point loads such as thin furniture legs, BBQ’s or planter stands.

  • What are its weathering characteristics?

    Independent test research has determined that PERMADECK™ Vault decking will experience virtually no fading, as it is co-extruded with a durable outer shell.

  • How does PERMADECK™ Vault compare with timber in terms of surface temperature?

    Tests have shown PERMADECK™ Vault has a similar surface temperature to timber of similar colours and finishes.

  • Is it UV Protected?

    Yes. PERMADECK™ Vault has a very a high degree of UV stability.

  • Can PERMADECK™ be used for joists?

    No. PERMADECK™ Vault is not designed to be used for structural framing.

  • Can PERMADECK™ Vault be installed on both timber and metal framing?

    Yes! The Hidden Fasteners are designed to be used on both systems but the screw for the metal is a self-tapper. Please always specify to your supplier whether you are using timber or metal framing. The only limitation with metal framing is that composite decking and metal will expand and contract at different rates and for this reason PERMADECK™ must NOT be fixed directly to metal framing.

  • Does it burn?

    PERMADECK™ is less combustible than timber but will burn so should not be exposed to direct flame.

  • Is it Borer resistant?


  • Is PERMADECK™ slippery?

    No. PERMADECK™ Vault has a High Slip Resistance (HSR) embossed surface and is a fantastic solution for wet areas such as spas, pools, ramps & marinas etc. It scored an impressive .71 on the British Pendulum Test, one of the highest slip resistance scores in the market today!

  • Is PERMADECK™ suitable for use around swimming pools?

    Yes definitely, PERMADECK™ Vault is 100% waterproof and has a High Slip Resistance embossed surface.

  • Can PERMADECK™ be used by the sea?

    PERMADECK™ Vault is ideal in a marine environment, being unaffected by salt air and moisture.

  • How can I clean and maintain PERMADECK™ Vault?

    PERMADECK™ Vault is relatively maintenance free. Sweeping and cleaning with normal household cleaners is generally all that is required. If organic matter builds up on the deck, removing it and then washing down using a mild solution of warm water and bleach or products like 30 Seconds Spray & Walk Away, will restore it beautifully.

  • Should I paint or stain PERMADECK™ Vault?

    No. Staining or painting is not needed and will void warranty.

  • Is PERMADECK™ Vault mould resistant?

    Yes. PERMADECK™ Vault is mould resistant, however without sufficient ventilation or in areas where organic debris can collect and does not get washed off, mould may appear. Mould and mildew may grow on the deck surface in some circumstances, especially in damp shaded areas, or if in high humidity before installation. Failure to keep packs dry in storage can lead to the growth of mould spores on boards. Clean as per directions under Care and Maintenance.

  • Are there special tools required for working with PERMADECK™ Vault?

    No. With PERMADECK™ Vault you can use standard woodworking tools. Being a durable product it will wear blades faster than wood. As with using any power tools, safety glasses and face masks should be used when cutting or drilling PERMADECK™ Vault. The PERMADECK™ sawdust is coarser than wood and that doesn’t tend to float in the air. This makes it safer for working.

    Note: a slower spinning circular saw is less likely to cause melting or “glugging” of your blades & cuts due to friction.

  • How should PERMADECK™ be stored and handled?

    Whether at the timber merchant’s premises or at your own property awaiting installation, PERMADECK™ Vault should be stored in a dry, flat area under cover. Failure to keep packs dry in storage can lead to the growth of mould spores on boards. When storing, PERMADECK™ Vault should be supported on flat ground by 10 or more “Gluts” or bearers.

  • Is PERMADECK™ Vault guaranteed?

    Yes, PERMADECK™ Vault has a 25 year removal and replacement warranty. Please refer to the warranty section for information. All product performance claims are based on PERMADECK™ products being used as recommended and installed in accordance with PERMADECK™ fixing specifications.

Contact our knowledgeable team if you would like to know more about Permadeck™ Composite Decking solutions.

Call 0800 952 952 or email

Click here to order a free sample.