Flat Roof Drainage Design Guide

The following outlines ways to build protect and reinforce your roof.

Flat roof drainage design guide.

This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table. In order to ensure a finished surface with zero fall a design fall of 1 80 should be used and a detailed structural analysis should account for construction tolerances settlement and for. Here we ll discuss types of flat roofing. Most flat roofs suffer from poor drain locations or drain levels that are high.

There are many advantages to using a flat roof. The good news is that there are a variety of drainage options for your flat roof each with their own benefits and drawbacks. Having sufficient drainage on a flat roof is vital. Interior drains gutters and scuppers.

Choosing a flat roof design. Built up roofing bur this multi layer roof design is a proven system that has been around for generations. Your building and location can help determine which drain will fit your roof needs. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally.

Flat roofing does not drain naturally like sloped roofs that can rely on the force of gravity to remove water. To help you choose the right one here s a guide to the five best flat roof drainage systems and why they re such a vital part of keeping it in perfect condition. Guide to flat roofing drainage systems and epdm. 6 24 2014 david howard aia said.

The result is the number of drains needed. They require a root barrier to stop the plants interacting with the waterproofing beneath and a flat roof in particular requires a drainage layer to retain water. Flat roof design guide some bauder waterproofing systems are bba approved for use with zero falls but back falls are not acceptable and should be corrected. With a new structure in the design stages or part completed you need to know that your blueprint is going to work.

Along with the benefits of a flat roof come unique challenges. The most critical of these issues is the flat roof drainage systems. When designing a roof it is essential to pay close attention to where the drains are. Some pipes are too small to handle the volume of the water.

This guide explains the advantages and disadvantages of the three most common flat roof drainage solutions. Take the roof s total square footage and divide by the total square footage handled by one drain. The critical role of flat roof drainage systems. If you are considering an epdm flat roof for all or part of your building work then a key question is how water will drain away from the flat surface.

The above sizing data is offered as a guide only. Why flat roof drainage is important. Calculate drains needed. By mark brinkley 26 may 2020.

On many occasions drains are too high and water cannot flow off.