Flat Roof Drainage Requirements

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

Flat roof drainage requirements.

As opposed to old built up. Along with the benefits of a flat roof come unique challenges. Take the roof s total square footage and divide by the total square footage handled by one drain. Roof drains for flat or low slope roofs come in a few standard types.

Flat roof inspection checklist. The result is the number of drains needed. Size horizontal storm drainage piping. Flat roofs are an often lower cost and easier to install alternative to traditional pitched roofs.

This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table. Appendix b in the ipc provides rates of rainfall for various u s. In normal circumstances wait until 48 hours after a rainfall to clean and inspect the roof. If you re thinking of installing a flat roof it s important to make sure you are up to date with all the rules and regulations before you begin with a new flat roof construction.

What is the general area of a flat 1 4 1 0 slope single ply roof for each roof drain ratio for the number of roof drains roof area. These drains are placed in areas of the roof that collect the. They are common on extensions garages and commercial buildings. We describe online roof drainage requirements calculators pertinent plumbing standards a table approach to looking up roof drainage.

Calculate drains needed. The most critical of these issues is the flat roof drainage systems. It is a requirement of building regulation part h that adequate provision is made for rainwater to be carried from the roof of the building. Select number of roof drains and calculate the roof area sloped to each drain.

Any water should have evaporated by this time. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally. The above sizing data is offered as a guide only. Fitting the roof with one of the following systems to ensure proper drainage will help keep it protected.

6 24 2014 david howard aia said. Cities based on inches per hour that may fall during a storm of one hour duration and a 100 year return period. The best type for the application depends on several factors such as the size and slope of the roof the desired appearance and how much regular maintenance the drain system might need. According to bs 6229 bs 8217 flat roofs should be designed with minimum falls of 1 40 to ensure a finished fall of 1 80 can be achieved allowing for any inaccuracies in the.

Roof drainage requirements specifications. To design a sloped or flat roof drainage system we need to know the anticipated maximum rainfall rate and the flat or projected roof area. Leaving your flat roof without a drainage system will greatly increase the risk of these issues. This article describes several methods for determining the drainage capacity required to safely drain water off of building roofs whether from rainfall melting snow or a combination of those water sources.

What is a flat roof.