Months ago, I noticed something odd on the ceiling of our (attached) garage. The sheetrock appeared to be separating slightly and there was a stain indicative of water damage. I didn't think much about it at the time as other things were going on and because, well, I was just optimistically hoping that I was just seeing a shadow or something.
Several weeks ago I saw a similar stain elsewhere in the garage ceiling. The first crack also appeared to be discolored more and longer.
I went into the attic to investigate, but found nothing.
I called our roofer (we had the house done in late Sept.) and told him I might have a problem. He was here within an hour and looked both in the attic and on the roof to see if he could find evidence of what might be wrong. His search was in vain and he said that we'd need a good rain to see what might be happening.
We had 0.8" of rain Thursday morning and it wasn't until this pm when I thought, "Hey, I better go up and check to see what I can learn." Still, I find no evidence of water -- but now I see two additional cracks along the sheetrock seams. I don't see signs of staining (in either one yet). Part of me wonders if maybe these new cracks are stress fractures I caused when I added my weight to that of storage up there, right in the center of the beams spanning the width of the garage. (Ceiling joists are 2x10's on 16" OC.)
- All cracks are along sheetrock seams and perpendicular to the joists.
- The center points of each crack are almost all in a N/S line (our home faces east).
- The southern most crack appeared, followed by the northern one, then the two intermediate ones. (Garage door faces due east.)
- No leaks are apparent where the ceiling and wall sheetrock meet.
- There is no plumbing in the garage save for the water heater. The input water line comes up through the wall by the heater (not over the garage), and the heater itself is in the far SE corner of the garage -- away from all the leaks. Examination of the water heater (about 1 yr old) and plumbing shows no evidence of leaks.
- Other than the water heater, there's no plumbing or venting (other than the roof's ridge vent) in the garage.
- There's no obvious sign of water leaking on the roof's decking, rafters, or floor joists.
- There's no obvious trace of water or water damage to anything in the attic or on the attic side of the sheetrock.
At this point, my strategy is to empty the garage attic entirely, pull up what little sheathing I layed to store things on, put down some plastic, dust the plastic with something (so I can see any traces of water flow), and hope for rain.
By way of background, we bought the home new and it's 11yo. Location is in central Texas.
Any advice on this puzzler would be VERY MUCH appreciated.