How To Build A Deck Over A Flat Roof Correctly

The sleepers aren t fastened in place and the floor floats.

How to build a deck over a flat roof correctly.

Strips of 4 in wide epdm provide a layer of protection between the sleepers and the roof. Then you will install sleepers or flat 2x6s laid flat every 16 on top of the roof surface. First you must make sure the roof is strong enough to support 55 lbs per square foot. Build the frame of the roof on the ground.

These decks are often referred to as floating as they are not secured in place as a stand alone structure. Since you have the space raise your deck 5 install a ledger against the house with carriage lag bolts install joist hangers. They are merely placed on top of another structure. Building a deck over a flat roof is very similar to building a deck over a concrete patio.

Then run joists connecting the front of your roof with the rear every two feet along the length of your roof. Frame up a box the size of the outer dimensions of your deck using 2 by 4 inch lumber. The drainage system flashing details and waterproofing membrane that go over the structural deck are the key to success. The most common approach is to use a heavy gauge epdm membrane typically 60 mil as the roofing membrane usually placed over rigid insulation.

Whenever i install decking over a roof i make sure the framing is structurally sound and properly pitched to drain water. How to build a deck over a flat roof correctly your roofer is right and your framer is in catch 22.