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Cliff Rohrabacher
10-20-2006, 6:58 PM
I have a 20 x 40 12/4 flat roof.

It's a ply sheath with tar paper and 70# mineral felt with a 50% overlap and on the top the main roofing material is that torch down stuff with a 4" overlap.

The roof is leaking around the lowest edge not dripping but soaking the ply thru to the inside about a foot up in some places.

It's not wind driven as I installed a large (fabbed up from roll flashing) custom drip edge to keep the water away from the building.
There is a large load on the roof as I have a 20 x 40 foot deck on top.

I am wondering if the pads on which the stringers set have slowly destroyed the torchdown cutting through and maybe cutting the mineral felt too.

The mineral felt along the lead outside edge is crumbling and wet.

The roof is just over 10 years old.
Any ideas?
Does my anlysis dound about right?

Lee Schierer
10-21-2006, 11:18 AM
In my limited experience, over a long period of time weight can cut through tar paper and most tar based roofing materials. If you can jack up the supports where they are pressing on the roof, I suspect you will find that the roof has been cut or cracked due to the weight load peressing down on it. You might be able to patch the holes, but the problem will return unless you can spread the weight out over a greater area and reduce the pounds per square inch significantly.

Cliff Rohrabacher
10-23-2006, 10:01 AM
In my limited experience, over a long period of time weight can cut through tar paper and most tar based roofing materials. If you can jack up the supports where they are pressing on the roof, I suspect you will find that the roof has been cut or cracked due to the weight load peressing down on it. You might be able to patch the holes, but the problem will return unless you can spread the weight out over a greater area and reduce the pounds per square inch significantly.

The heat of summer the cold of winter would exascerbate the issue of weight with movement.

I am not eager about this process it's a big deck.