Parapet Roof Drainage Design

Adding a parapet wall makes a flat roof far safer than leaving the roof s edge exposed.

Parapet roof drainage design.

Working with manufacturers will help develop your understanding but don t delegate your design responsibility to them. The most dependable type of roof drainage design is the inverted pyramid pattern. With a parapet wall it is possible for a roof to retain or pond water should the primary roof drainage system fail. Requires a primary drainage system with.

Architectural home design software all content support videos chieftalk forum. In these cases the. From the edge of a valley. Typically surrounded with parapet walls to screen roof top equipment and to provide.

In many cases these buildings have parapet walls that surround the perimeter of the roof. Back up secondary emergency drainage system in case the primary drain. Roofs of this design will have one or more roof drains or scuppers installed. If a building has roof access that residents use regularly for whatever reason adding a parapet greatly decreases the chance that someone could fall over the.

Parapet and valley gutters are treated differently because they have a higher risk of failure. Looking at a building from the ground a parapet may seem to simply be a design choice that adds little more than a characteristic look to a building. This type of pattern is particularly useful on buildings that are easily divided into rectangular areas. This kind of drainage system is most common on small flat roofs where water volume and buildup isn t extreme.

At page top and at left our photos show a low slope roof surrounded by a parapet. Install a drain at most 50 ft. Manually adjust roof planes to have a negative pitch to create a parapet wall structure with a center drain. The drainage requirements for flat roofs on buildings present some special problems that we describe and illustrate here.

From a roof edge. This would be in situations where a retaining wall or parapet prevents direct access to the roof s edge. Provide adequate flashing for parapets openings walls joints skylights etc. It s also sometimes used in tandem with scuppers.

Watch for clogs blockage at the roof drain or scupper. Buildings that incorporate flat roofs with centralized roof drains and internal downspouts are another story. Limit the number of parapet walls. However parapets block the drainage of rainwater from freely flowing over the roof edge.

On larger and more complex schemes specialist consultants may be employed to design the rainwater drainage system. The premise of the pattern is that a drain is positioned in the center of the rectangular area and there is a four way positive slope into the drain.