Roof flashing examples.
Examples of roof flashing. Courtesy of Peter Weddell, owner/operator of Qld Home Buyers Inspection Service and Queensland Building Inspection Service, QBIS.
This is a photo of two flashing’s that have been fitted to cover the gap created between the concrete roof tiles and the external brick wall to stop water entry to the house interior. This is the main purpose of most roof flashing’s.
There are three stages to this stepped flashing.
- The first is hidden within the brick wall (damp-course) that is fitted during construction of the wall.
- Damp-course barrier fitted to the top level of the bricks and stepped down to suit the roof pitch (angle) and located above the roof tiles.
- A flashing is then fitted under the damp-course and stepped down the face of the bricks.
- The last flashing is fitted behind the previous stepped flashing and extends over surface of the roof tiles, facing down into the tile.
Weep-holes locations, above a roof:
Different perspective of the flashing with weep-holes visible (vertical gap between the bricks). The bottom of the weep-hole is where the damp-course barrier is fitted, within the brick wall.
- A horizontal tray has been fitted to the upper section within this chimney. This has not been completed.
- A flashing must also be fitted just under the tray and extend down and over the lower level flashing.
- Without the additional flashing, seepage is most likely to occur through the exposed area of brickwork to the house interior from bricks being porous.
- Salts to the exposed section of bricks inside the house below the ceiling are usually are an indication of seepage occurring.
Extract from BCA (Building Code of Australia). This is an illustration of a preferred method of fitting roof flashing from the BCA manual, when bricks are exposed.
- Flashing has been fitted around a vent pipe (usually from the bathroom area).
- The flashing is too short as it does not extend over the tile ridge and down into the lower section.
- This can allow water to enter the roof cavity and possibly cause damage to the ceiling lining below.
- A wider flashing or sealant is required.
Roof flashing examples. Problems with flashings to split level areas of a roof:
- Typical method of fitting a single flashing between the wall and roof sheeting with sealant applied to the top side of the flashing.
- This method is deemed acceptable, if the wall has been covered with a water impervious product.
- Because sealants break down over time from being effected by UV, it is not my recommended method of fitting a flashing.
In most cases this can be rectified easily by fitting an additional flashing that is cut into the wall above.
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