Replace any missing or rotted siding above the step flashing on dormers.
Leakage control roof.
Recaulk the corner flashing if any areas have hardened caulk.
If a leak is difficult to find enlist a helper and go up on the roof with a garden hose.
Other times the best way to fix a leaking roof is to completely replace it with brand new asphalt shingles.
The first step on how to stop water leakage from concrete roof is to find the source.
These are the most common sources of leakage.
I would think if anything the air leakage through a roof would be a minor problem at best in terms of condensation control i ve seen many examples of serious air leakage fueled condensation in roof assemblies where the convention rules of thumb and hygrothermal modeling predicted little or non condensation accumulation.
Isolate areas when you run the hose.
For example soak the downhill side of a chimney first then each side then the top on both sides.
Your tiles are old and fragile which causes them to lose integrity during severe weather conditions.
Personally accessing your commercial roof is a risky task.
This technique prevents the water from spreading across.
Sometimes it takes a few roof leak seals to completely repair a leaking roof.
Control the damage water can travel on the underside of sheathing or down roof rafters before dropping off in one or more places.
Dig out any cracked or dry caulking that isn t properly sealing adjoining surfaces and replace with silicone caulk.
Roof inspection is a process performed by professional roofing contractors.
Check the entire roof surface look out for ponding water and inspect the plumbing lines.