Leak Detection Help
I am looking for a little help here.
I have a spot in the master bedroom (next to the wall separating it from the master bathroom) that is getting wet. If I put down paper towels and some weight on top I might get a moist spot about the size of an apple. At another time, It might soak three layers of paper towels. We might go 5 or 6 days with not moisture whatsoever. We might go 3 or 4 days after the last rain with no moisture. I can run all of our indoor water utilities and it won't recreate the moisture. I can go 5 or 6 days without moisture, using all the utilities as per usual. Note that my house is on a slab.
Here are some questions:
1. I made sure none of our indoor or outdoor utilities were running. I then went out to the water meter and recorded the number, the position of the triangle, and the time. I watched the little triangle and it wasn't moving at all. After 30 minutes I re-checked it. The number had not changed and the triangle had not moved. I turned on the outdoor hose and saw that the triangle immediately started moving. Doesn't this mean that I DON'T have any leaking pipes?
2. I thought I might have water coming under the slab. Where the brick meets dirt I didn't notice any rodent holes or anything and I don't get standing water. Where the brick meets with concrete slabs (back porch, front porch, driveway) there is the usual material separating the house from the concrete. In a couple of places this material was worn and there were holes. I filled a few of these with self-leveling concrete crack filler – is that ok to use for this purpose? Note that I still had a water spot after plugging holes.
3. If it isn't a broken pipe then it must be coming from the roof or from under the slab. It is impossible for me to get to that area in my attic but I am going to do my best to try and make a path to that area so I can look during our next rain. Is there anything else I can be doing? I just don't notice anything around my slab. It is easy to get up on the roof, but I don't notice anything out of place there. I do have a vent stack in the area and the flashing isn't completely covered – should I perhaps put some kind of spray foam or something around this – what should I use?
Any advice would be most helpful. And by the way… if I have to pay someone to crawl into my impossibly tight attic and create a plywood path across two rooms…. What sort of estimated cost would I be looking at (Mississippi prices)?