Deck Roof Construction Step-by-Step

A deck roof is not really that architecturally logical as snow and rain will shed off much faster on a slanted roof. However, for the modern-designed buildings, a deck roof is at the center of architecture, meant to imitate the wide horizontal space of a natural landscape.

Step by Step

1. You will first need to frame your roof. To avoid water from accumulating and getting stuck on your roof, you will need to build it with a slight incline of at least 1/8 per foot. There are many that drop or lean in several directions like a hip roof, for example; it leans directly towards scupper holes.

2. Cover the top with 5/8’ plywood, all the while leaving a gap of 1/8 inch on all the dividing points to allow for contraction and expansion.

3. A rubber sheet material for roofing usually requires the use of a substrate that is called ISO board. This is a rigid foam about ½’-thick made from polyisococyanurate paired with a special backing fiberglass. This ISO board can be easily cut using a utility knife. You will then need to anchor this into the plywood with screws and steel washers. This provides a protective, soft base for your rubber sheet.

4. To create slanting corners on both sides, the roof should be adjacent to the parapet (a low protective wall found in most deck roofs). This will need the rubber roof to accumulate the walls and be glued to the plywood.

5. Before you place the rubber down, sweep first the space so as to rid it of any debris that might puncture the newly-installed roof. Ethylene Propylene Diene Monomer (EPDM) comes with ten-foot wide rolls that you can easily cut with a knife or shears. What you will do is to cut a large piece that can cover up the roof with an allowance of 9” all around. Grab the piece, spread it in place then fold it up in half.

6. Make use of a ¼’ paint roller with an extension pole and spread the glue all over the open section of the ISO board and folded rubber, then leave it to dry. Once it is all dried up, spread or paste the rubber on top of the board, all the while pushing it down to eliminate any wrinkles that might form inside the folds. Do this in sections and finish up the remaining parts of the roof by smoothing out the air bubbles with the paint roller before you start fastening the edges up your wall.

7. At the inside of the vertical corners, cut and overlay the EPDM and use the rubber adhesive so that it seals down tightly. Use the rest of the uncured rubber to seal the seam. Make use of metal brackets or termination stops to help fix the vertical sections of the wall in place and to keep it from falling off. On top of the edges, seal them off with the use of a water tight sealant to finish the edges.