DekTek Tile's Alternative Roof Deck Install

DekTek Tile's Alternative Framing Installation for Roof Deck

 

 

Installation Instructions for Roof Decks

This page shows DekTek Tile’s alternative framing method for building a roof deck.
We also offer a different system called the Pedestal Pad Roof Deck Installation, which does not use joists. You can view that method and video on our Pedestal Pad Roof Deck page.

 

Step 1: Ensure Proper Waterproofing

  • The roof deck must be fully waterproofed prior to installing DekTek Tiles.

  • DekTek Tiles are not a waterproofing system.

  • The waterproofing should be completed using a preferred method that complies with local and state building codes to prevent water leakage.

  • Verify the roof surface is watertight, sloped for drainage, and ready to accept framing.

 

Step 2: Plan & Install a Perimeter Border

  • A mechanically fastened border must be designed and installed around the perimeter of the roof deck to keep the tile system locked in place.

  • In this project, the parapet wall serves as the border solution, which is the simplest method.

  • For decks without parapet walls, see our Roof Deck Border Solutions page for additional options and installation methods.

 

Step 3: Protect the Waterproof Membrane

  • DekTek Tiles should never be installed directly on the waterproof membrane. The concrete weight could damage the roofing surface and prevent proper water flow to drains.

  • It is not recommended to rest joists directly on the waterproof membrane, as this may void the roof warranty and interfere with proper drainage.

  • Use rubber pads (as shown in this video) or another waterproof, structural material to shim the joists slightly above the membrane.

  • Space shims to keep joists elevated, allow water to drain freely, and help prevent joist rot.

 

Step 4: Lay Out Joists (Sister Joist/Sleeper System)

  • Install a sister joist or sleeper system that provides enough surface area for DekTek Tiles to rest securely.

  • Secure pressure-treated 2x joists on top of the protective pads/shims.

  • Keep joists spaced 16” on-center to properly support the tiles.

  • Check for level and adjust pad thickness or spacing as needed.

 

Step 5: Install DekTek Tiles

  • Begin laying tiles from one corner, working outward.

  • Each tile is designed to sit directly on the joists, spanning across the supports.

  • Secure tiles to the joists using a polyurethane construction adhesive.

  • Joint Spacing: Leave a gap between tiles of 1/16”–1/8” (most common), but up to 1/4” if desired. DekTek Tiles are 15-15/16” in size, allowing for 1/16” joints on standard framing. If you prefer wider joints, modified joist spacing may be required when framing your deck.
    FRAMED JOISTS SPACING → TILE JOINT SPACING NEEDED:

    • 16” o.c. → 1/16” (critical for decks 20 ft or longer)

    • 16 – 1/16” o.c. → 1/8” (critical for decks 20 ft or longer)

    • 16 – 3/16” o.c. → 1/4” (allowed on any deck size)

  • Continue across the deck, cutting tiles as needed for edges or transitions.

 

Step 6: Finishing Touches

  • Secure perimeter tiles or use trim details as needed.

  • Check drainage to make sure water flows through joints to roof drains.

  • Clean up and enjoy your finished roof deck!