We were called into an apartment to thermogram a wet ceiling (poured concrete slab)in a bedroom. We decided on 2 courses of action, to see how the damage would progress. This is what we did:
1) We disconnected the drain on the split a/c unit in the upstairs apartment to see how the water damage would develop downstairs and if in fact there was a clogged drain affecting the downstairs apartment.
2) we gave instuctions to repair a hot water supply pipe in the vicinity of the damage just in case this was the cause
We did this to try and eliminate causes of problem and trying to establish whether or not condensation was the cause.
After these two courses of action, the water damage in the apt below has been very inconsistent. There have been days when it is dry and days when it is damp again. Also the damage has changed in shape and has migrated (pic attached) A lot of the original wet, damaged area has completely dried off and now the damage has moved, although it still appears as on big area.
1) To determine whether or not it is condensation, should we apply the dew point alarm on the damaged surface? Maybe the condensation is in fact coming from above and filtering down or maybe it is the same apartment and its a/c use that is causing condensation on the concrete ceiling slab. Should we use the dew point alarm in the damaged apt. with the a/c operating or not?
2) Are there signature damage patterns than can help us determine whether is is condensation or a leak from another source (which we highly doubt)
3) If it is in fact condensation, what are the best reccomendations (ie vapor barrier, moisture barrier) that we can give our clients to minimize future damage. The upstairs neighbor will probably not want to reinstall flooring to place barrier on his side of the concrete slab. What can our poor client do on his end?
4) We performed the courses of action above to see how the poured concrete ceiling would develop. Is it possible that the cause was in fact the drain pipe and the ceiling continues to be wet because it is "drying out"? How much time can it take for a concrete slab to dry out? We are approaching 2 months.
I am attaching a pic of the damage so you can see shape and intensity.