10 Tips for Installing Composite Decking

January 6, 2020
HomeOutdoor Living Ideas10 Tips for Installing Composite Decking

This is the fourth installment in our DIY decking series. Check out the third installment on ideas to inspire your deck design. In this article, we break down 10 tips related to installing composite decking.

Explore our Deck Building Resource Center for easy-to-follow process tips and install best practices. VISIT THE DECK BUILDING RESOURCE CENTER

Picture it: You’re moving along with your DIY project; you’ve decided on the type of deck you plan to build and you’ve locked-in your design. It’s time to get started — but you could use a little guidance when it comes to installation. We get it. Installation guides can feel dry and daunting. Even after you’ve decided you want a top-tier, composite deck that combines premium appearance with superior performance, the excitement can dwindle when you see pages and pages in a manual.

Where to start? Lucky for you, we’ve combed our resources and tapped our expertise to pull the top 10 tips and best practices for installing TimberTech® capped composite decking. Read on to ditch the nerves and begin translating your decking dreams into reality.

1. The Right Project Needs the Right Tools

Recently, we outlined the kinds of general tools you will need to get your project started when you’re choosing the right decking materials. Here are a few other basic items to have on-hand before installing composite decking:

  • Chalk line
  • Tape measure
  • Carpenter square
  • Spacing tools

No decking project can start without fasteners — the hardware that holds together the boards, fascia, and riser boards. Read on to learn how to choose the right fasteners to match your design.

Step 1: Choose Your Preference Between Hidden and Color-Matched

There’s essentially two ways to go when it comes to fasteners: hidden and color-matched. Here’s the low-down on each one.

Hidden FastenersColor-Matched Face Fasteners
The head cannot be seen when looking at a fully built deck.The head is apparent when examining the boards.
Certain hidden fasteners are to be used with grooved boards. Others pair with square shoulder boards.Compatible with all profiles and types of boards.

Step 2: Select Your Product Line

Your fasteners will depend on your product line: TimberTech® AZEK, TimberTech PRO®, or TimberTech EDGE®. Check out which fasteners and accessories go with the eye-catching decking line you’ve chosen by matching the type of board with the product line and fastener type. Each line has a robust selection of hidden and color-matched fasteners for you to choose from.

2. Achieve a Finished Look With Fascia

Fascia is made up of the boards that run along the perimeter of the deck. Not only does fascia finish your deck with a sleek, seamless look, but it’s also a useful tool when hiding the ends of your composite boards.

Check out this installation video for more.

Ready to Start Your Project?

Print out this project checklist to help guide you through the design, education, and budgeting tools linked above. Then, bring your finished checklist – and deck – to life with your contractor.

3. Dress the Part

Safe installation doesn’t only mean opting for the right tools — it also means prioritizing the right apparel. Safety glasses should be worn during the entire installation process, even when power tools aren’t actively being used. Comfortable, secure shoes and more fitted garments that won’t catch or tear while lifting or laying the deck boards are both important pieces to the safety puzzle.

4. Don’t Be Shocked by Static Electricity

Don’t worry — the buildup and generation of static electricity is a naturally occurring phenomenon in many composite decking boards. While the light show might surprise you, know that static electricity is naturally occurring and not a defect.

5. Watch for Excessive Heat

One of the many impressive qualities of TimberTech AZEK decking is its ability to be heat-bended into eye-catching patterns and unique shapes beyond wood’s capacity.

During installation, however, this property means that AZEK products should be kept away from excessive heat sources — think fire or sunlight reflected from energy-efficient window products, like Low-emissivity (Low-E) windows. Low-E glass can cause unusual heat build-up and elevated surface temperatures, which may contribute to melting, sagging, warping, discoloration, or increased weathering.

Look out for Excessive Heat when installing composite decking.

 6. Avoid Excessive Construction Debris

During construction, make sure the deck’s surface remains clean and clear of excessive build-up of dirt, sand, and dust from concrete, tile, landscape blocks, or any other masonry. If these materials are not removed, the deck boards may become difficult to clean in the future and there’s the potential for damage to the deck’s finish.
As a best practice, install your TimberTech capped polymer or capped composite decking after all other construction projects — such as siding, roofing, painting, etc. — have wrapped.

7. Build Consistent With Your Foundation

Depending on the placement of your deck, there are different structural considerations to take into account. Here are some helpful tips from our product experts — you can find more details in the TimberTech Installation Guides.


A concrete foundation will require a sleeper system to get the deck off-grade — i.e., above ground level. A sleeper system is a substructure comprised of joints that sit between a solid surface, such as concrete, and the actual deck. Sleeper systems promote air circulation and water drainage — which in turn protects capped composite or capped polymer deck boards from excessive moisture — and prevent buildup of snow, sleet, or ice.

Rooftop decks

Rooftop decks will also need the improved airflow of a sleeper system substructure. Just like with a concrete deck on the ground, the improved airflow minimizes debris and bacterial buildup or accumulated snow, sleet, and ice — all of which can shorten the life of your deck.

Check out the TimberTech AZEK Decking Installation Guide and Installation Guidelines page for more detailed information.

8. Remember That Lighting and Angle Impact Color Appearance

If you’re a veteran DIYer, you’re probably familiar with the experience of metamerism. The phenomenon happens when two colored samples — both the same product and hue — appear the same shade under one light source, but then appear to be two different shades under another. The experience may tempt you to think you see undue color variation in your TimberTech boards, especially if you’re installing the boards at different angles.

Fortunately, metamerism is a perceptual issue caused by perspective and temporary lighting angles, not a performance or product warranty issue.

Consider lighting and color when installing composite decking

9. Consider Expansion and Contraction

Unlike wood, whose size fluctuates with moisture changes, both capped composite and capped polymer decking, as well as rim joist covers, will expand and contract with changes in temperature. The expansion and contraction may result in slight gaps, likely noticed at the ends of boards or in splice joints. Expansion and contraction will be most significant in areas of extreme temperature change.

Here are some best practices to keep in mind to allow for expansion and contraction when installing capped composite decking:

  • Always leave 1/8” to 1/4” gap between deck boards during installation.
  • Fasten your deck boards as soon as possible after cutting.
  • Keep decking as cool as possible during installation for best result and avoid direct, full sun exposure for prolonged periods.
  • Be sure to keep butt joints tight; do not leave a gap at butt joints, splices, or miters.

Fastening the deck boards according to the full Installation Guidelines will assist in minimizing expansion and contraction.

10. Remember Your Resources

With TimberTech, you never have to go it alone.

When it comes to “how-to,” we’ve got you.

Turn Your Deck Dream Into Design

Play with shapes, colors, lighting, and railing to bring your deck ideas to life with our custom Deck Designer tool.

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