Flat Roof Deck Drainage

At page top and at left our photos show a low slope roof surrounded by a parapet.

Flat roof deck drainage.

For flat roof drainage where you place your drains scuppers and the final material of the roofing is more important. It was more like seepage and so in roof decks and balconies the roofers introduced a drainage gap. To provide drainage the panels should slope toward the outside edge of the deck about 1 4 in. What s the difference between a regular roof and a flat roof and why does it require different material.

The most critical of these issues is the flat roof drainage systems. The angle is not significant enough to prevent water from pooling on the surface. The slope takes water to the drains. Roofs of this design will have one or more roof drains or scuppers installed.

Watch for clogs blockage at the roof drain or scupper. The deck surface should be installed so that proper ventilation and drainage can occur. The key is in the word flat. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally.

If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in. The drains take water to the ground. 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. Roof drains watts roof drains provide flexible solutions for specifiers and installers in any commercial roof application.

Your building and location can help determine which drain will fit your roof needs. The drainage requirements for flat roofs on buildings present some special problems that we describe and illustrate here. To keep damage like leaks from occurring water should not stand on a flat roof for more than 48 hours. 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. Our exclusive dual functional structural deck flange and combination roof drains streamline specifications saving installation time and labor. The roofers recognized that not a lot of drainage occurred in the mortar bed despite the crushed stone around the drain. Along with the benefits of a flat roof come unique challenges.