Sources Of Flat Roof Failures - Inspection Guidance
- Procedure code:
- Hspg Prepared For Nps - Sero
- Thermal And Moisture Protection
- Membrane Roofing
- Last Modified:
SOURCES OF FLAT ROOF FAILURES - INSPECTION GUIDANCE
This standard includes guidance on identifying sources of flat roof
failures by looking at specific problem areas.
1. Inspect Exterior walls of building:
- Settlement cracks
- Stained or displaced flashing or drainage facilities
- Efflorescence on the wall - this may be a sign of leaks
in the coping or parapet above.
2. Inspect interior walls of building:
- Damp or stained walls
- Chipped or discolored paint
3. Inspect underside of roof deck:
- Wood deck: rotted or warped boards
- Concrete or gypsum deck: cracks and stains; spots of
rust may also appear on a concrete deck from wet
reinforcing rods in the concrete; a gypsum deck may spall
as a result of leaking water.
- Metal deck: rust spots
4. Inspect roof surface:
- A sprung board in a wood deck. Identified by sharp
indentation of roof surface, often caused by a broken
- A noticeable "give" in the roofing under weight.
- Cracks in membrane.
5. Inspect drainage: Make sure drains are flush with the roof
and free of debris.
- Change in original slope of roof
- Standing water
- Blocked drains and/or gutters
6. Inspect copings:
- Cracks, gaps or damage to coping joints
7. Inspect flashings:
- Loose, torn or missing flashing
- Improper bond between base flashing and edge of mat or
between counterflashing and wall
- Flashing that is not turned up enough potentially
allowing water to back up, stand against the wall and
leak down into the roof deck
- Rust on flashing or lack of protective coating on
8. Inspect roof at least twice a year and inspect after any
- Debris accumulation and vegetation growth
- Deterioration of the surface and membrane
- Deck deflections (sometimes from structural problems)
- Ponding and tensile splitting of water weakened felts
- Ice formation and resulting membrane damage
- Positive drainage
- Wear spots at curbs and penetrations
- Ruptures, bare spots, splits, metal flange splits,
- Warping, cracks, splits, slivers, cupping and rot
9. Note priority of defect (i.e. none, minor, major, complete
10. Note changes from last inspection.
END OF SECTION