Originally Posted By: anatol polillo This post was automatically imported from our archived forum.
Greetings,
My question concerns flat roofs. They have a slight pitch and are built up and tar covered. If you see tar drops when inspecting the attic crawl space, does this indicate a leaking roof that was badly sealed? The roof sheathing on most of these is planking, usually with a 1/2 inch gap. I know if you see ice-cicles at this time of year it would be a leak, but what about tar-cicles?
Anatol
(who has a 3 year old town house on the schedule for tomorrow)
Originally Posted By: rsummers This post was automatically imported from our archived forum.
I have been involved in 100’s of Re-Roofs as the Sheet Metal dude and been in the attics of a lot of commercial Blds with hot moped Roofs. Its not unusual to see Tar that has came thru the cracks. You learn not to walk out under them when they are being roofed.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
The method of roofing, and re-roofing, that I am familiar with requires a base sheet (also referred to as an anchor sheet or dry-in sheet) mechanically attached to the roof deck (in the case of wood, it would be nailed down), then the other plies hot mopped to that base sheet.
That allows very little (if any, but I will go with very little) hot mop asphalt to leak between the decking boards. Occasionally, there will be some around flashings (plumbing vent stacks, exhaust vent roof caps, etc.).
If there was a lot of hot mop asphalt dripping through, I would wonder how that much got under the base sheet (did they use a base sheet? did they lap the base sheet properly? did they tear the base sheet?) things like that.
Originally Posted By: dkeough This post was automatically imported from our archived forum.
Not a big deal. I have been in the roofing business for the past 12 years. You have roofs that have gaps 1/2 inch wide. Sometimes when you are wheeling around your mop cart, people walking around, material being moved, little tears in the paper are common. Hot tar will fall into these cracks and cause these icicles. You are probably mopping a couple of plies and then a capsheet. Nothing wrong with the roof. With tongue and groove sheathing it is recommended to use a resin paper under the base sheet so when the asphalt seeps thru the base sheet it won’t adhere the base sheet to the decking and seep thru the tongue and groove.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
To my knowledge, that type of roofing is required to be done on ‘solid decked roofs’, no 1/2 space.
That is for the exact reasons David gave which caused (allowed) the tar icicles.
Walking around and rolling wheelbarrows around, tearing the base sheet, and that is ACCEPTABLE? Not in my book. Sorry, David, I don't buy that. Those roofs should have been re-decked.