Roof Drainage Plan

The most critical role of the drainage layer is to provide an adequate flow of water off the roof during and after rainfall.

Roof drainage plan.

Ipc provides four steps to size the roof drains on a building. Deck balcony and railing connections should be designed and constructed to shed or drain water to the exterior. The drainage plane and drainage logic should encompass the entire building enclosure. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond.

A typical commercial or multifamily residential building will utilize one of the following types of primary roof drainage. Can keep water from pooling and building up near the building foundation. Historically roof drainage was ac complished by simply sloping the roof downward. Protects doorways and window openings.

This form of roof drainage is preferred if a clean exterior appearance is desired. Garages decks and terraces should be sloped to the exterior and drained. 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. Keeps water from pouring off of the roof in an uncontrollable manner.

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. 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. Which method is used will depend on how the building is designed and or the type of public sewage system used in the area. Inexpensive gutters are the easiest types of drain systems to get and install.

Roof plans a roof plan is used to show the shape of the roof. For some types of roofs a roof drainage plan may also be drawn. Roof framing and drainage plans will be discussed in chapter 30. Rain gutters are the most common drain system in use for all types of roofs.

Materials such as the roofing material vents and their location and the type of underlayment are also typically specified on the roof plan as seen in figure 20 3. Roof plans are typically drawn at. Roof wall connections and roof dormer connections should be designed and constructed to shed or drain water to the exterior photograph 8. Water could then pour off overhanging roof eaves onto the ground below or in more sophisti cated assemblies flow toward the perimeter and into a clay wood or metal gutter system or through a drainage outlet in the exterior walls.

Green roof solutions offers many different drainage layer options depending on system goals regarding water retention. Roof drainage methods there are three basic methods covered in chapter 11 of the uniform plumbing code that are used to deal with stormwater that falls upon the roof or in and around a building.