Roof Drainage System Plan

Secondary drainage shall be provided through the use of sidewall scuppers or internal roof drains.

Roof drainage system plan.

Determine 100 year 1 hour rainfall rate used for location of building select number of roof drains and calculate the roof area sloped to each drain size horizontal storm drainage piping size vertical storm drainage piping. In the case of a building with gutters tcwill usually be the sum of the time taken for water to flow down the roof and the time taken for it to flow along the gutter to an outlet. Typically a steep slope roof slope is equal to or greater than 3 inches of rise per 12 inches of run 25. Deck balcony and railing connections should be designed and constructed to shed or drain water to the exterior.

Your building and location can help determine which drain will fit your roof needs. Developing the design criteria for a roof drainage plan that will perform with the roofing system to drain the roof is critical priorto the bid process and roof system installation. Inner roof drains are used on flat roofs and include a low section or channel that collects water and feeds it into a concealed drain that leads to an underground drainage system. In either case the discharge shall be located so that it is readily visible by building occupants.

The drainage plane and drainage logic should encompass the entire building enclosure. The design of the different drainage layers allows for a portion of the stormwater to be retained above where the water is allowed to flow freely off of the roof. To prevent erosion make a rock bed around the end of the tube. Establishing a minimum slope is critical because most steep slope roofing as.

Inner drains are resistant to freezing but can require careful maintenance to prevent problems. The main benefit of inner drains is that the system is hidden from view. Screw a drain cover over the end of the tubing as it approaches daylight to keep critters out. Functioning drainage system for steep slope roofs is to maintain a minimum roof slope.

Secondary or emergency roof drainage is required wherever the buildup of water is detrimental to the roof structure. Roof wall connections and roof dormer connections should be designed and constructed to shed or drain water to the exterior photograph 8. Ipc provides four steps to size the roof drains on a building. Green roof solutions offers many different drainage layer options depending on system goals regarding water retention.

The most critical role of the drainage layer is to provide an adequate flow of water off the roof during and after rainfall. 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. Design assistance services are offered as a courtesy to the roofing design professional and contractors to ensure the project s success.