I'm trying to help a school get a few more years out of their built up roof. It has slight blistering of the torch down cap sheet & quite a bit of ridging from movement. When I go to the manafactures web site's I can't find info on repairs they only SPEC's on complete systems. Site's I've to are Manville, GAF, Tamco, Certinteed, & others. Google was no help either.>>>
Hi KC,
Now that gives me an idea.
The big question is would you pay to join a site or have access to such expertise on a one to one basis ?
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Dose anybody know of a non bias site with spec details??? :unsure:>>>
Yah we sliced the blister to make 4 or 6 triangles & melted them back into the roof then doubled patched on that.>>>
Robby the Roofer Said: is to cut out affected area quote] Rozziroofer - Cut out affected areaIncorrect, in my opinion.
Vaa Fakaosifolau -Cut the blisters with a knife
Correct.
You dont cut anything out. You make one cut from one end of the blister to the other. Yes, i know it is mopdown. Your blisters are probably circular and range from one to three feet around. Burn it back down to the fiberglass mat with a torch. Then Torch new rubber over it with granules.
The reason you dont cut it out,is because it will leave the area pooled and takes much effort to back fill the area. You also have to burn it back down because if you dont then your old modified will want to force itself up into its previous bulged up position.
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I'm in the middle of it now.
I decided to cut out minimum as possible only where it tented 3/8" or more, apply mastic where I cut out the high tenting, set loose lay minimum 1 1/2" each of shifting area with mod scrap granual side down to get additional flow at the edge of my loose lay, clean & prime old roof, then cap over that 6" each side of the loose lay.
Seems to be working fine.
I do have some concerns still.
The old roof is about gone & is a hot mop cap not a torch as I orgional thought.
I just painted on the primer thin and let dry about 1 or 2 hours then torched.
Had a hard time getting a bleed out flow from the cap (it either didn't flow or damaged the top side) I wish I used a different material then Ruberoid Torch (thicker heaver more mod bit to melt)
And I think the tenting was leaking. The orgional core's I took I found wet fiber board & Insulation. No other signs of leaks & when I cut the tenting out in some cases I did find cracks in the built up ply's. To much wetness to be condinsation. We installed (6) 1 way vents & resealed with rag & mastic the parafit joints. Blisters we doubled patched.
My contract orgionaly is with another company instaling a new AC unit. We were to take out 3 old AC sleepers & installed 4 new ones & I offered this maintance as an option to the school. Knowing the traffic on the old roof away from our work area wasn't doing it any good. Trying to take care of my contractor if you know what I mean.
If someone would tell me how to enter photoes I would post them Vaa you know to.
Thanks for the input guy's it did help.
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Jane i mean jed Not wrong completely fine done it a thousand times. try it. using mastic 2 ply would be best READ THE TOPIC he's only tryin to buy time read twice before you look dumb again. (you still have chit on ur face.)>>>
I got to agree with Vaa. I prefer to either heat & embed the granules or heat and remove them. The torch my patch down so I've got bitumen to bitumen. Kinda like a homemade salvage edge.>>>
Cut out affected area / clean and use mastic or clean and use torch. Both will work fine. Mastic is my way 2 ply. Cover over patch with another scrap. (Removal of granules can only help but is not mandatory.)>>>
Jed Said: Robby, as long as you use an asphalt primer on the old mod bit before you torch down the patch it will stick permenantly.
That was my next ? if I should use the primer.
The Tamko detail didn't mention primer.
now do I need to scrape the granuals first or just prime & torch? (I hope)>>>
Robby the Roofer Said: Never did like torching a patch over patch. More than not the surface is dirty, it may adhere initially but come apart later. The technique I use (wether it is hot mopped or torch cap) is to cut out affected area and re-patch with mastic and cap sheet over-lapping the old material by at least 6-8 inches, use a 4 inch roller to compress material and get a decent bleed, then dress the bleed with same colored granules.
You don't us a torch at all?>>>
The roof consist of concrete deck - tapered foam insl - perlite - 2 ply hot mop - tamko torch cap sheet white granuals.
One spec I found said to loose lay modified smooth versa flex over cracks over 1/2" 6" each side of crack then torch new cap 8" beyond the loose lay.
This equals 40" of material. Seems like over kill & waste of labor & material. My repairs arn't cracks but ridges from movement.
I'm tring to catch it befor it dose crack
I do like the idea of the loose lay in there though to allow for any new movement.
My main ? do I need to cut the ridge out or just cap over it?
Can I loose lay a 6" strip & cap with a 18" strip?
Can I use the cap material for the loose lay?
If so smooth side down or up?
I would send a photo if I new how I can't find directions on how to attach a photo only emotions..
Also a good resource for spec's would nice to have for back up for procedure & presentations>>>