Anyone out there with experience using CertainTeed Flintlastic SA (modified bitumen) and even more specifically the “peel and stick” variety of the membrane?
I’ve got a question then. We’re going to be using the stuff for a greenhouse roof (new installation) and adjacent to the greenhouse is another flat roof that while in perfectly fine shape we’ll want to cover in the Flintlastic membrane so the colors match. As I just said the flat roof on the adjacent structure (12 x 14) is dibutin that was applied over an older copper roof and it’s in good condition so we don’t want to get into removing it. So my question is we clean and then prime this existing roofing before we apply Flintlastic SA Mid Ply or do we just clean the roof and then apply the Mid Ply layer since it’s adhering to an older asphalt roof?
Then of course the Flintlastic SA Cap sheet goes on to finish the installation.
Any other tricks and quirks to this stuff that anyone knows about we’d love to hear them too.
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Bump. What no one out there's used this stuff?
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First question, what are you calling a flat roof?
Read the manufacturers specs, I wish I did. Anything under a 2 in 12 pitch and the peel and stick will leak. I suspect a 3 pitch will also leak with a little ice damming
I'm not talking about peel and stick Ice Damming products. This is a product intended for flat roofs. The Application Handbook for this product says:
And the existing flat roof has more than that. I think it was 1" per foot and it already has a good roof on it anyway. We're only adding this new roofing there for the sake of matching the color of the roof we are doing on the greenhouse and the new replacement roof on the greenhouse that we're fabricating has 1-1/2" per foot. Most torch down modified bitumens I think call for 1/8" per foot but this product it's 1/4".
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>>I'm not talking about peel and stick Ice Damming products. This is a product intended for flat roofs.
I know exactly what you are talking about. Like I said I used it for a very slow pitch and ended up replacing it in two years with copper. That roof was 1 in 12.
I would'nt use it again in a snow climate.
I've used a two layer SBS peel and stick from another maker (maybe still have the box at home). For the non-roofer, it's a whole bunch safer than torch down.
The one problem is that the peel away layer will tear diagonally if it gets a tiny nick in the edge, and it's no fun trying to get it started peeling again. The peel away layer is split down the middle, you do one side first, and if it tears on the other side you may have a pointy end trapped with stuck-down material around it.
-- J.S.
Thanks John, that potential peeling problem is good to know about.I decided to give this a try over torch down precisely because one side of that existing flat roof tucks up next to an old wood roof. The only way we would torch it was if we had a fire truck onsite.
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Jerrald, on that peel problem: We do this a lot with split-backing ice & snow membranes. Start the peel from the inner corner of the backing and pull that corner so the backer folds back under itself until it comes out past the edge of the membrane itself. Then just keep pulling the backer at 90 degrees to the run of the membrane. This way the inner edge is always peeled 18" ahead of the outer edge. And the likelihood of a nick in the inner edge is smaller.
That old method of rolling up the backing around a broomstick is the biggest PITA I've ever tried (I tried it once, LOL...).
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
Jerrald - I've done two roofs where it was spec'd on the plans. In both cases, the main reason it was spec'd was to match the Certainteed shingles on the rest of the roof. It's not stocked by our local distributors and they had to buy a minimum order (at the time, they were not manufacturing certain colors until they were ordered, so we had to purchase the entire run) which was much more than we needed.
We ended up not using it. It looks like a good product for what it is, but I don't think it's been on the market a long time. IIRC, the warranty doen't apply to residential use.
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I had used the Certainteed product fairly often until we went with torch-down on my crew (when I was roofing, 10 yrs exp). We rarely had any problems, usually from installer error at protusions. I'm sad to say we did not prime as much as we should have but it wasn't my call yet still few issues. Peel from the center and don't bang the rolls around when transporting and loading the roof-ding the edge and it'll bugger the backing when peeling. Enjoy the static shocks! I mucked all eaves and rakes. I liked putting "F" metal along the eaves, with "C" edging bedded in muck under the roofing capped by "H" or slag-stop along the rakes. For protrusions, I bedded vent collars in muck with the bottom edge ontop of a run of stick down and then stick down over the collar. Think of it as one giant shingle. I'm not familiar with "dibutin" so I would prime as recomended.
First thing in the morning, measure your lengths and roll them out and cut, adding 2 or three inches for trimming with a hook blade. Let them lay out for a half hour or so and then loosely roll them up to carry and install. This "relaxing" promotes adhesion and helps with getting all edges down nice and tight, especially at the end of the roll. For endlaps, nail down the bottom edge with roofers. Roll out the next piece in place unpeeled. Using a kiel mark where the top layer lays on the lower. Carefully muck close to the line. If you have ooze-out, you can get a bag of granules of your color from Certainteed, just sprinkle like jimmies and don't step in it!
Wow, great tips mbdyer. Just the kind of hints I like to hear and they all make good sense. I never would have thought about the static shock but that figures too. Looks like we're going to do this Wednesday or Thursday next week.
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Watch the weather, Katrina is may be affecting the Philly area Tues or Weds. Not sure where in NY you are but check it out.
Not much experience, but I just did a 4 sqr area (1.5/12 slope) on the back of a home with Certainteed Flintlastic self-adhering (the product you specified) and my buddy and I think it's a great product. It went down easily and we got no air bubbles. We did not use the mid-ply, just base and cap.
I'm not sure that I understand your question, but for covering the older roof, the online manual shows that the cap sheet is only to go on top of either their mid-ply or their base sheet. They show no application where the cap is stuck directly to anything (including flashing) other than mid-ply or base. I'm thinking if I were doing your job I'd be considering putting the base down over the old roof. Or at least I'd check with Certainteed so I didn't install contrary to their requirements.
I'm interested to hear what you choose to do. My buddy and I are thinking of doing one of his commercial buildings with this product.
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