Low Slope Roof Drainage

Low slope roof drainage.

Low slope roof drainage.

One of the most common we see is the lack of proper drainage. On a flat roof you don t get the same slope so the water has nowhere to go. Consequently the roof drains must be located on the plumbing drawings up slope from the low point. Typically though there is a steel beam at the low point which prevents the installation of the roof drain at the low point.

The asphalt roofing manufacturers association arma recommends that roof designs provide adequate slope minimum of inch per foot to ensure that the roof drains freely throughout the life of the building and to thereby avoid the effects of ponding water. Prudent designers would like the roof drains to be located at the low point of the structurally sloped roof deck. 4 x 5 downspout scupper box scupper with sleeve closed top scupper with sleeve open top 7 gutter shop fab gutter more search low slope. A traditional roof on a home is slanted.

Here at boak sons our commercial roofing repair technicians are experts in spotting potential problem areas on low slope roofs. The building was unoccupied at the time of a cursory audit. Through building drains upper right in the sketch become clogged internally and burst flooding the building or leaks occur around the drain itself where it penetrates the roof. This allows water to run down the roof into the gutters.

Proper drainage cannot be emphasized enough when discussing or reviewing the requirements of any well drained low slope commercial roof system figure 1.