Flat Roof Deck Drainage

Watch for clogs blockage at the roof drain or scupper.

Flat roof deck drainage. To provide drainage the panels should slope toward the outside edge of the deck about 1 4 in. Our exclusive dual functional structural deck flange and combination roof drains streamline specifications saving installation time and labor. If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in. 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 key is in the word flat. At page top and at left our photos show a low slope roof surrounded by a parapet. The most critical of these issues is the flat roof drainage systems. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally.

For flat roof drainage where you place your drains scuppers and the final material of the roofing is more important. The angle is not significant enough to prevent water from pooling on the surface. Lower than the purlin along the house 12 x 1 4 3. Removing ponding water or puddles on a flat roof can easily be done by installing a 12 shower drain from home depot.

The drainage requirements for flat roofs on buildings present some special problems that we describe and illustrate here. The deck surface should be installed so that proper ventilation and drainage can occur. Roof drains watts roof drains provide flexible solutions for specifiers and installers in any commercial roof application. First mark all the purlin locations on the deck joists.

The slope takes water to the drains. What s the difference between a regular roof and a flat roof and why does it require different material. It was more like seepage and so in roof decks and balconies the roofers introduced a drainage gap. The roofers recognized that not a lot of drainage occurred in the mortar bed despite the crushed stone around the drain.

To keep damage like leaks from occurring water should not stand on a flat roof for more than 48 hours. Along with the benefits of a flat roof come unique challenges. 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. Your building and location can help determine which drain will fit your roof needs.