A customer once told us about the drip they could hear at night. It's in the bed room a small drip, drip, drip.
What could it be?
She was told by others she should replace the roof to find the problem.

After inspection, we find that the shingles look good and there is nothing to cause a leak from the roof. Let's not tear off the shingles.

When is it leaking? "Every night I can hear it drip." It's not raining outside but it drips. "No one can see a problem but I hear it at night."

We inspect the attic: it's dry. We craw around and notice extra PVC pipes running horizontal in the attic. These pipes connect for the plumbing stack. There are two bathrooms and they ran the PVC pipes together. Usually these pipes run vertical not horizontal across the attic.
If you look at the pipe above her room it's stained. A water stain! The seal on the pipe is bad. The moisture from the plumbing stack is dripping. A slow light drip, drip, drip.

We found the leak and it was a lot cheaper than buying a new roof
Now she can get some sleep.