Looking for sticky & stretchy roof ice & water barrier
A bit late in the season (zone 5), but I’m finally getting to the stage of roofing on some parts of my project. I have a number of complicated roof areas and roof/wall intersections, so I need a fully adhered waterproof underlayment (ice & water barrier) in quite a few places. We picked up a couple rolls of Certainteed Winterguard Sand to try because it’s what the local lumberyard stocked, and after our first application of it today I’m not impressed.
On the stickiness front, it’s basically just sticky enough to not slide off the roof. To be fair to it, the temperature was only about 60F today — but that’s actually warm for this season, and it’s not going to get any better! The part on the roof would be workable, but the real problem area was the roof to wall intersections — it would basically just fall right off my foil-faced polyiso wall insulation. I ended up taping the top edges of it with 6″ wide 3M 8067, which seems to hold it (and later there’ll be furring strips and siding and such, which should hold it in place better), but it would have been nice for it to stick better by itself. It also doesn’t give me confidence that it’ll stay attached to the roof — we continued tarping the roof tonight because it feels like it could blow right off.
On the stretchiness front, it has none. I have some wall-corner-to-roof intersections, and the details I’ve seen for these usually involve some extra little patch piece that gets stretched somewhat around the corner — but this stuff doesn’t have any stretch at all. I had one tricky area tonight that I ended up layering a couple differently cut pieces of this stuff, and also taping it with Contega Solido Exo (not at all appropriate for the application I’m sure, but that stuff sticks to anything!)
To continue complaining a bit 😉 it has a sand-coated surface, which allegedly improves traction or something when working on the roof — but we found that the sand tends to rub off easily and sometimes makes it more slippery.
I was able to find a roll of Grace I&WS at a Home Depot about 25 minutes away (not stocked at any of the three in a 15-minute radius though), and picked it up tonight to try tomorrow — it seems to be a highly-rated product (but is also about 3x the cost of the Winterguard). Thought I’d ask here too to see if anyone recommends an ice & water barrier that is sticky and at least a little stretchy! Bonus points for low application temperature (both Grace and Certainteed instructions state a 40F minimum, which is going to quickly become a limiting factor). Also, it may be a bit before I can actually get roofing on, so something OK with exposure for a few months would be good!
Failing the above, any advice on detailing tricky wall-corner-to-roof intersections with non-stretchy underlayments?
I guess I’ve been spoiled working with Proclima tapes and membranes that stick super well and are usually at least a bit stretchy!
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Replies
Jonny,
Resisto is pretty sticky. I don't know how readily available it is there.
https://www.resisto.us/en/product/multipurpose-waterproofing-membrane-1988/
Granualted ice and water is best avoided for this. Very weak, easy to tear.
I generally use Grace select as it is cheaper. It won't stick in cold and does not stretch. It is also non-walkable with any snow on it. In colder weather you can staple the edges to keep it in place until the sun warms it enough to really stick.
I've also used VP100 on roofs. This does stretch a bit and very sticky. It can take a bit of foot traffic but not too much.
For complicated intersections, I usually use a cheap peel and stick until you get to the corner and a better tape for the corner detail.
If your roof is reasonable slope, the best temporary roofing is a decent synthetic roof underlayment. Doesn't have to be peel and stick, just nailed/stapled up, maybe a bit of tape around questionable areas and 2x2 to hold down the edges. There also vapor permeable ones (Breathex, Deck armor) if you are looking to avoid a vapor barrier. You can still tape the seams of your roof deck under the underlayment with a quality tape if that is your air barrier.
I've never had a problem with Grace Ice and Water shield, and it's pretty much the standard around my area. It's so common I never even bothered to look into alternatives, so all these other products mentioned in this thread are new to me.
Do use care to install the Ice and Water shield OVER the drip edge on the edge of the roof, BTW. So many people put it under the drip edge flange, which isn't the right way to do it. You want everything on the roof to overlap with stuff higher up on the roof always overlapping on TOP of stuff lower down on the roof. If in doubt of where something should go, ask yourself "if water runs down this, will it be able to get UNDER the edge of something". If the answer is "yeah, probably", then you probably laid it down incorrectly.
Another thing to be careful to do is to use at least two strips of ice and water shield on the lower edge of the roof. One roll width of the stuff really isn't enough. I've heard of people covering their entire roof with ice and water shield, but I think that's overkill in most cases.
Bill
> Do use care to install the Ice and Water shield OVER the drip edge on the edge of the roof, BTW. So many people put it under the drip edge flange, which isn't the right way to do it.
For what it's worth, there are differing schools of thought with this, summarized well by Mike Guertin here: https://www.jlconline.com/how-to/roofing/drip-edge-and-ice-barrier-membrane_o
I think the chance of water getting in from above i more likely than building up from below. The drawings in your link do show the ice and water shield wrapping over onto the fascia board though, which is better than just ending at the edge of the sheathing which is what I usually see with the “drip edge on top” installs.
If you’re concerned with water coming up from below with an ice dam in the gutter, I would use hybrid method D in the article at that link, which I think offers the best protection overall.
Bill
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