Flat Roof Flashing Height

Minimum of 12 to top of parapet.

Flat roof flashing height.

What typical detailing methods are used to seal flat roof penetrations. Which would include abutments rooflights and service vents etc must have a minimum height of 150mm. Bs 6229 2003 flat roofs with continuously supported coverings code of practice and bs 8217 2005 reinforced bitumen membranes for roofing code of practice both state that if unwanted water ingress into the building is to be avoided all weatherproofing upstands occurring around the roof area. Vertical flashings must be a minimum of 8 inches above the completed roof surface.

An approved sealant is then applied to the top of the membrane upstand before it is tied off with a jubilee clip. The 8 inch height prevents water from pouring over the top of the flashings into the building or system. This dimension should be measured from the finished surface of the roof which would. Venting in wood framed parapets.

Banding is typically used to seal soil vent pipes on single ply roofs such as fdt rhepanol pib and involves wrapping an unreinforced membrane around the pipe to a minimum height of 150mm. For example 3 tab shingles usually have a 5 5 8 inch 143 mm exposure. Top of parapet below cap to be sealed with fluid applied flashing. Typical methods include banding pitch pockets and cover flashings.

Typically 10 by 8 inch 253 mm x 203 mm flashing is chosen. This height has become the industry standard and is recognized by most membrane manufacturers. L shaped flashing is a versatile general use flashing used where a uniform or strengthened finish is needed on a 90 surface. Further your step flashing pieces need to be 10 inches 254 mm long and at least 2 inches 50 mm wider than the exposure of the shingle you re using.

Do not lap tpo over top of parapet unless required by unique construction conditions.