Reading a Flat Roof Moisture Survey — A Practical Guide
What a real inspection covers on a flat roof in Sherman Oaks, and what usually gets skipped.
A roof inspection is only as good as what gets looked at, and a lot of what gets called an inspection is a walk round the garden with a phone camera. This is what a real one covers on a flat roof in Sherman Oaks.
What actually matters
Flat roofs are not flat. They are built with fall, and the fall is what keeps them alive. Every other detail is secondary to whether water leaves the roof. An inspection that does not account for that is looking at the wrong layer.
The detail that is usually left out
An inspection is only as good as what gets looked at, and photographs of specific defects are what let you get a second opinion without a second visit. Drainage does not fail in the storm; it fails in the eight dry months beforehand. A drain that has been dry since April collects grit, leaves and debris, and nobody looks at it until water is coming through a ceiling. Anything under half an hour on an average house has skipped something.
What is specific to Sherman Oaks
Summer is the problem here. Sherman Oaks sits inland at the foot of the mountains with nothing to moderate it, so a roof surface that reads ninety degrees at the coast is well past a hundred and fifty on Foothill by mid-afternoon, and it holds that heat for weeks. Everything on the roof expands into it and contracts again overnight, and that daily movement, not the peak temperature, is what opens laps and backs fasteners out. Much of Sherman Oaks went up between the 1950s and the 1970s, which usually means original decking, ventilation that was never sized for this much heat, and often a layer somebody roofed straight over rather than tearing off.
The full inspection list
- Fall across the roof, and any area holding water beyond forty-eight hours
- Drain and scupper clearance, including underneath every strainer
- Membrane condition across the whole field, not only at the edges
- Flashing at every penetration, curb and item of rooftop plant
- Parapet termination and counterflashing along the full perimeter
- Insulation moisture, established by probe rather than by eye
- Evidence and quality of previous patching
Common questions
How long should an inspection take?
Long enough to get on the roof and into the attic. Anything under half an hour on an average house has skipped something.
Should I expect photographs?
Yes, and of the specific defects rather than general views. Photographs are what let you get a second opinion without a second visit.
The honest summary
Ponding, blocked drainage and failed penetration detail account for nearly every flat roof call we take. If a quote does not mention drainage, it is a quote to recreate the same problem in a new material. In Sherman Oaks the thing to watch is attic temperature and intake ventilation, because a Sherman Oaks attic that cannot breathe cooks the underside of the roof as hard as the sun cooks the top.
Free inspection, drone photography where access is difficult, and a written estimate with deck repair priced per sheet. No obligation.