Find answers to common questions about composite decking, railing, and fencing.

Can I build my deck directly over an existing deck?

COOWIN composite decking is ideal for replacing your old deck on an existing sub-structure, but not to be installed directly on top of existing deck boards.

Can COOWIN composite decking be installed over an existing substructure, e.g., framing or joists?

Yes, as long as the existing substructure is free of damage or decay, and the joists are spaced in accordance with COOWIN Decking Installation Instructions, to ensure good ventilation and drainage.

Can I build a fire pit on your composite deck?

Fire pits should not be placed directly on COOWIN composite decking, it can cause damage to the surface of COOWIN composite decking via direct exposure to the flame, excessive radiated heat, or embers. But fire pits may be installed with a thermal insulating structure made of stone or other fire-resistant materials between the fire pits and COOWIN composite decking. 

Can I paint or stain your decking boards?

You can paint or stain on our uncapped decking boards only, but not on our capped decking boards. However, paint or stain is not necessary as COOWIN composite decking is designed with rich color options, you’ll find everything you want on the color palette. Furthermore, it’s free of rotting, splitting, splintering, or insect damage.

Can I use your WPC products for structural purposes?

No, COOWIN composite decking does provide superior surface integrity and strength, suitable for various project applications, but it cannot be classified as a “load-bearing” product or used for structural purposes.

Does your decking require pre-drilling to install?

Yes, predrilling and countersinking prior to driving screws are recommended as they help to achieve neat fastening and finish, and avoid board splitting and screw shearing. For more information, refer to COOWIN Composite Decking Installation Instructions.

What type of tools are required to install your composite product?

COOWIN composite decking is ideal for home improvement DIY as it can be easily installed with standard woodworking tools including rubber hammers, power saws and drills, level, and tape measures, etc.

I have a wood deck and want to replace some boards. Can I replace them with composite boards?

Yes, you can replace wood boards with COOWIN composite though there are a few factors to take into consideration. First, you need to make sure your substructure is code-compliant, confirm that the COOWIN board you selected has the same thickness as the wooden board it is going to replace to ensure your deck remains smooth and flat. Although replacing old wood deck boards with COOWIN boards can be done, it can result in an undesirable patchwork appearance. A better option, if your substructure is code-compliant, would be to replace your entire deck with all COOWIN deck boards.

Is it okay to install your composite decking around a pool?

Yes, COOWIN composite decking is ideal decking for the pool and spa environment. Also, as there is no likelihood of splinters occurring, it protects your feet. It’s required that you follow the Installation Instructions to make sure the ventilation requirements are met.

Can I install your WPC products near saltwater?

Yes. Saltwater won’t affect the performance of our WPC material.

Can your WPC products be installed at any temperature?

Yes, our WPC products can be installed at any temperature, but the installation requirements may vary according to the temperature. To ensure a satisfactory installation, please follow those specific requirements on contraction gapping in our Decking Installation Instructions, or consult your builders.

Can your composite decking be placed directly on a solid surface?

No, COOWIN composite decking can only be installed over a solid surface with a code-compliant substructure that allows for adequate ventilation, drainage, contraction, and expansion. A proper slope for drainage, e.g., 2-5 degrees, is compulsory to keep a dry condition under the deck.

Can I install your composite boards without spacing?

No. Our composite boards must be installed with proper spacing to allow for water drainage, ventilation, and normal expansion and contraction. Installation without spacing may cause damage to the edge of deck boards. For more details, please refer to COOWIN Deck Installation Instructions.

Can I install your products myself or do I need to hire a builder?

Yes, you can install COOWIN composite products by yourself as they can be easily installed with standard woodworking tools, including rubber hammers, power saws and drills, level, and tape measures, etc. COOWIN composite decking is ideal for home improvement DIY.

How do you cover the ends and grooved edge of boards?

COOWIN L-corner or bullnose board is optional for covering the ends or grooved edge.

Can I install your WPC product with another manufacturer’s accessories, like hidden fasteners?

No. COOWIN fasteners are recommended for use when installing COOWIN decking or wall cladding. Using another manufacturer’s accessories may result in an unsatisfactory installation, and void your warranty.

Can I use glue or caulk with my decking?

No. Do not use glue or caulk to fasten COOWIN composite boards or to seal between any of our boards. This will impede the drainage of the board and inhibit the natural expansion and contraction of the boards.

What would you recommend using for the understructure of a deck?

COOWIN composite decking works well with substructures made of a variety of materials, like natural lumber or pressure-treated lumber. COOWIN composite or metal joists are recommended are preferred as they are designed specifically for COOWIN decking.

Can you rip a composite decking board?

Yes. Our composite boards can’t be ripped to reduce thickness but can be ripped to reduce width.

What are fascia and riser boards?

Fascia and riser boards are thinner and wider versions of deck boards that serve as a non-structural covering for rim joists, stair risers, and stringers. They are sometimes referred to as “skirts” or “trim” boards.

Can I overhang your composite decking over the edge of my deck?

Yes. COOWIN composite decking may overhang over the edge of your deck, but overhang is not recommended to exceed 2 inches (or 50mm).

How do I install your WPC product?

Installation Instructions and videos are available on our website, you can also follow us on YouTube or consult our sales staff for more information. Before installation, you are advised to check with local building code officials for any special requirements or restrictions.

How do I finish a cut edge to match the color of my decking?

We provide L-corner or bullnose boards in the same color tone to match the color of your decking. In other applications, a solid color-matched stain or paint may also be used to coat the cut ends of the deck boards.

Can I install multiple colors of the same product together?

Yes. COOWIN composite products with multiple colors are physically identical, they can be mix-installed together, to create a unique and interesting look for your outdoor space.

What kind of blade can be used to cut your composite boards?

Any standard woodworking blades will work well with our composite boards.

Can I use a nail gun to install your composite decking?

No. We do not recommend using nails or nailers, but using screws when installing composite decking. The material is very dense and getting nails to penetrate to a proper depth without bending can be a challenge. We recommend that all holes be predrilled to help reduce mushrooming, and avoid splitting. When using nails or nailers, the concern is that the ends would not be predrilled and possibly lead to cracking and splitting.

How much gap should I leave for expansion or contraction when installing?

As temperatures fluctuate, composite deck boards will naturally experience thermal expansion and contraction. There should always be a gap between the butt ends of the boards to allow for expansion and contraction and a gap between the edges of the boards for water runoff. For more information, refer to COOWIN Deck Installation Instructions.

Is ventilation required under a deck?

Yes. It is very important that there be adequate and unobstructed air flow under the deck to prevent excessive water absorption. Improve drainage or grade flat areas where standing water may gather. For decks with limited ventilation, 1 inch of clear ventilation is required.

How do varying weather conditions affect your decking during installation?

COOWIN composite decking performs well in varying weather conditions, having the lowest thermal movement among all wood-alternative decking. During installation, COOWIN decking will contract only slightly in cold weather. In hot weather, it expands. We recommend that the material is on the job site 48 hours prior to installation to acclimate. Follow the installation instructions on spacing guidelines to ensure proper room for expansion and contraction.

What is the maximum joist spacing for your decking?

Joist spacing requirements vary according to the product type you’ve chosen. You are advised to follow our Installation Instructions and local building codes.

Can your product be used in bushfire-prone areas?

COOWIN composite material is made of wood flour and plastic. As an alternative to natural wood, it can be used wherever the natural wood is suitable. But neither wood plastic composite nor natural wood is bushfire proof.

Can I put your decking over a concrete floor?

Yes, you can put COOWIN decking over a concrete floor with COOWIN composite or metal joists. But do not install decking directly to an existing or solid surface. The deck design must allow adequate and unobstructed air flow under the deck, and water must be able to flow away from under the deck.