DIY Network

Add a Waterproof Barrier to a Patio Roof

A two-layered waterproof barrier is added between the plywood and tiles on this patio roof.

More in Outdoors

new patio roof transformation
  • Time


  • Price Range

    $500 - $1,000

  • Difficulty

    Easy to Moderate


Step 1: Start Farthest From the House

The waterproof barrier used on this roof was two-layered, with each layer requiring the same installation method. Roll out the first row on the end of the roof farthest from the house and cut the ends to leave about 1" of overhang on all sides.

apply waterproof barrier on furthest end of roof

Step 2: Fold, Stick and Repeat

Fold the piece in half to remove the plastic backing and expose adhesive. Stick this side down and repeat the folding to the other side and once again remove backing. Roll the next row out over the first, working your way up the pitch toward the house. When all rows are adhered trim the excess overhang closer to the edge of the plywood.

Step 3: Add Drip Edge, New Layer

Add a drip edge to the perimeter, then add the second layer of roofing material over the first layer using the same process. Be sure to let the second layer extend over the drip edge by at least a 1/4". Use a water filled roller to press all of the waterproof material together and into the plywood roofing.

To complete the job, add roof tiles followed by a touch of paint and patio furniture to finish the transformation of the patio into a poolside oasis.