I purchased a home last winter. An addition to the house has a flat roof with a gravel coating on top. Over the past summer in one small section 3'x3' I noticed 1" tar balls coming to the surface. What does this indicate?
Also the center of the flat roof slightly sags (no leaks). Can I add more gravel (which is already thin in this area) to increase grade and help pitch rain water to the edges where the drains are?
Seems counter productive to add weight to the lowest part of the roof, but a little added gravel (1/2") in my mind would displace the water from the center.
Thoughts???

 

Got a picture, sounds more like it may be blisters from water trapped under the tar.
Adding gravel is not going to displace the water.
Had a commercial roofer look this over yet?

 

Thanks Joe.

I'll get a picture this weekend when I go back up there.
I'm not having any leaks, but it could possibly be water under the tar. Sounds bleak. Ant the beginning of more issues to come.