Roof To Wall Flashing Flashcards
What factors influence the design of roof-wall flashing?
The roof surface orientation (horizontal or inclined), roof covering type, and wall covering material.
What are the two types of flashings used at roof-wall interfaces?
1.Base flashing: Prevents moisture from entering the roof-wall structure at the interface.
2.Counter-flashing: Prevents water running down the wall from getting behind the base flashing.
When can the base flashing be an integral part of the roof covering?
With roll and membrane roofing products, where the covering extends up the wall surface.
What role can siding play in roof-wall flashing?
Siding can act as counter-flashing, such as vinyl siding covering step flashing on a shingle roof, provided there is 1–2 inches of clearance to prevent water wicking.
What materials are commonly used for flashings?
Metals: Galvanized steel, aluminum, copper, and lead.
Lead: Common for masonry due to its malleability.
Base flashing: Corrosion-resistant metal or mineral-surfaced roll roofing.
Cap flashing: Must be corrosion-resistant metal.
What are the key requirements for sidewall base flashing?
Must be at least 4 inches in height and width.
Directs water onto the roof or into a gutter.
Vertical part must be continuous under siding, if present.
Why is interwoven base flashing often unsuitable for tile roofs?
Tile shapes are too complex. Instead, pan flashing (usually galvanized steel) is used beneath the tiles.
What type of flashing is commonly found with continuous roof surfaces like roll roofing or membrane roofs?
The roof covering often serves as the base flashing, and a cant strip is used to transition the covering to the wall.
What is the purpose of kickout flashing?
To divert water away from the bottom of the roof-wall interface, preventing it from entering the wall system.
