Flat Roof Deck Drainage

Your building and location can help determine which drain will fit your roof needs.

Flat roof deck drainage. Lower than the purlin along the house 12 x 1 4 3. Roofs of this design will have one or more roof drains or scuppers installed. What s the difference between a regular roof and a flat roof and why does it require different material. To provide drainage the panels should slope toward the outside edge of the deck about 1 4 in.

The key is in the word flat. Our exclusive dual functional structural deck flange and combination roof drains streamline specifications saving installation time and labor. Gapping the deck boards a minimal of 1 4 is necessary to prevent pooling water on the deck surface and top allow for air to dry the water that does not drain of the roof surface underneath. Removing ponding water or puddles on a flat roof can easily be done by installing a 12 shower drain from home depot.

To keep damage like leaks from occurring water should not stand on a flat roof for more than 48 hours. While the slope of your roof ensures that any water is shedded of the roof surface to the edge of the roof roof drainage makes sure that water gets from the roof surface to the ground. The deck surface should be installed so that proper ventilation and drainage can occur. If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in.

At page top and at left our photos show a low slope roof surrounded by a parapet. Roof drains watts roof drains provide flexible solutions for specifiers and installers in any commercial roof application. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally. The slope takes water to the drains.

The most critical of these issues is the flat roof drainage systems. The drains take water to the ground. Watch for clogs blockage at the roof drain or scupper. First mark all the purlin locations on the deck joists.

Along with the benefits of a flat roof come unique challenges. For flat roof drainage where you place your drains scuppers and the final material of the roofing is more important. The roofers recognized that not a lot of drainage occurred in the mortar bed despite the crushed stone around the drain. When a roof is flat it actually will have a very slight slope water is going to spend a lot more time in one place giving it more time to find a way underneath the roof.