How to Install Composite Decking (DIY Guide)

Posted By Hook Agency

Composite decking offers a durable and low-maintenance alternative to traditional wood decks. Whether you’re looking to upgrade your existing deck or create a new outdoor space, installing composite decking can be a rewarding DIY project. In this homeowner’s guide, we’ll walk you through the steps to install composite decking, ensuring your deck is not only beautiful but also built to last.

Inside this blog:

  • The required tools + materials for DIY installation composite decking
  • 11 steps for installing composite decking
  • Tips + tricks for a successful composite installation

Ready to learn how to install composite decking like a true pro? Start scrollin’!

Tools and Materials You’ll Need

Before diving into the installation process, gather the necessary tools and composite materials to ensure a smooth project:


  1. Circular saw or miter saw: To cut composite decking boards to size.
  2. Drill/driver: For screwing down the decking boards.
  3. Measuring tape: To take accurate measurements.
  4. Level: To ensure your deck is perfectly level.
  5. Spacers: To maintain consistent gaps between boards.
  6. Chalk line: For marking guidelines.
  7. Safety gear: Including safety glasses and hearing protection.


  1. Composite decking boards: Ensure you choose high-quality composite deck boards that suit your style and budget.
  2. Composite deck screws: Composite decking screws are designed specifically for use with composite decking.
  3. Joist tape: To protect the wooden joists from moisture.
  4. Pressure-treated wooden joists: To create the deck’s structural framework.
  5. Post anchors (if needed): For securing posts to the ground or framing.
  6. Concrete or gravel (if needed): For footings if you’re building a ground-level deck.
  7. Post caps (if needed): For finishing the tops of deck posts.

Step-by-Step Installation Guide

Below are 11 steps for how to install composite decking on your roof. We’ll preface this by saying, “Safety first!”, as it really is the most critical factor in any roofing project. So remember, you don’t have to go at this alone. You can always kick back and leave the ladder climbing to the pros at Boss Exteriors.

But, for those of you who’ve got the big DIY itch, we’ve got the 11 steps for installing composite decking on your roof below.


1. Plan and Design Your Deck 📏

  • Determine the size, shape, and location of your deck.
  • Create a detailed plan, including measurements and design features.
  • Check local building codes and obtain any necessary permits.

2. Prepare the Site 🏗️

  • Clear the area where your deck will be built, removing any vegetation, debris, or obstacles.
  • If building a ground-level deck, ensure the ground is level and compacted. Use gravel or concrete footings if necessary.

3. Install the Ledger Board (if attaching to the house) 🏠

  • Secure a ledger board to the exterior wall of your house using lag screws or through-bolts.
  • Ensure it is level and properly flashed to prevent water intrusion.

4. Install Wooden Joists 🪚

  • Place pressure-treated wooden joists on the ledger board or directly on the footings.
  • Space the joists according to the manufacturer’s recommendations for the composite decking you’re using.
  • Ensure the joists are level and securely fastened.

5. Apply Joist Tape 🌧️

  • Protect the tops of your joists by applying joist tape. This prevents moisture from infiltrating and damaging the wooden structure.

6. Create the Deck Frame 🔲

  • Build the frame by attaching perimeter joists around the outer edges of the deck.
  • Connect the joists with interior joists spaced according to your design and local building codes.

7. Install Posts (if using a railing system) 🪵

  • Secure posts at the corners and along the perimeter of the deck.
  • Ensure posts are plumb and properly anchored to the footings.

8. Lay the Decking Boards 🪚

  • Begin laying your composite decking boards perpendicular to the joists.
  • Leave a small gap between boards to allow for expansion and drainage. Use spacers to maintain consistent gaps.
  • Cut boards to size as needed using a circular saw or miter saw.

9. Secure the Decking Boards 🪛

  • Use composite deck screws designed for your specific decking material.
  • Place screws through the face of each board into the joists below.
  • Be sure to follow the manufacturer’s guidelines for spacing and fastening.

10. Add Railings (if desired) 🛤️

  • Install the railing posts and railings according to your design.
  • Ensure railings are securely anchored and meet safety codes.

11. Finishing Touches 🎨

  • Attach post caps to the tops of posts for a polished look.
  • Trim off any excess material, and clean your deck thoroughly.

Tips for a Successful Composite Deck Installation


Below, we cover some helpful tips for effectively installing composite decking.

Read the Manufacturer’s Instructions

Always follow the manufacturer’s guidelines for your specific composite decking product.

Choose the Right Fasteners

Ensure you use the correct type of screws recommended for your composite decking material.

Pre-Drill Holes

To prevent splitting, consider pre-drilling holes for screws, especially near the ends of boards.

Leave Room for Expansion

Allow for natural expansion and contraction of composite decking by leaving adequate spacing between boards.

Maintain Proper Slope

Ensure your deck has a slight slope (usually 1/8 inch per foot) to encourage water drainage.

Regular Cleaning

Keep your composite deck clean to prevent mold, mildew, and staining. Use a composite deck cleaner as needed.

Inspect Periodically

Regularly inspect your deck for loose boards, screws, or any signs of damage.

Boost Your Home’s Curb Appeal with Composite Decking

By following this comprehensive guide and these tips, you’ll be well on your way to enjoying a beautiful and long-lasting composite deck that enhances your outdoor living space. Whether it’s hosting gatherings or simply relaxing outdoors, your new deck will provide years of enjoyment for you and your family. And remember, always call on the pros if you’re at all hesitant to start a new DIY roofing project.Contact our expert roofing team to upgrade your home’s exterior today. Experience decades of industry experience from a family owned & operated company. We’re ready when you are!


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