Grant is coming up to put the copper roof on in a month or so. We discussed underlayment and he recommends titanium UDL 50. In reading the specs, they say it should be installed on a ventilated roof. I had planned on doing closed cell spray foam, itself a vapor barrier, without venting the roof.
Called the titanium guys and there stumped, they’ll be calling me tomorrow. Local distributor thinks another product, Titan something, which is permeable might be a better underlayment for me.
Any of you guys have experience with closed cell and titanium UDL together?
Thanks
Kevin
PS house is on an island off New Jersey coast, 21 miles long by a few blocks wide. One block from ocean.
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bump
I'm failing to understand the problem. If I understand correctly, the closed cell foam is vapor retardant. So there should be little if any moisture passing thru it and the sheathing.
By the way, the "permeable" underlayment leaks. Use #30 felt if you like or if you have concerns about the Titanium, we can slash it as we cover it.
http://www.quittintime.com/ View Image
Grant,
Not sure there is a problem. Just thought there might be a problem with a VB on both sides of the sheathing, Titanium on outside, and foam on inside. I want to avoid any problems down the road.
I was in a conference call a minute ago with the titanium rep and another guy from a different UDL manufacturer. They are sending me an email with links to another product, once I get that info, I'll post it here.
Thanks, as always,
Kevin
closed cell foam IS a VB! No need for another.
The UDL should not be a problem either
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Paul,
I know the foam is a VB, that's why I want to use it, so I don't have to vent the roof. I am concerned about the sheathing being sandwiched between 2 vapor bariers. Probably not a problem, but figured I'd ask you guys. I'd much prefer using a UDL with a long life expectancy to match the lifespan of the copper roof.
Kevin
I thought you were saying you'd add another VB under the roof rafters for a VB
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so you understand now and don't see a problem?
Not unless the sheathing is sopping wet when you spray the foam in .
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That's what I figured, but I wanted to make sure. Wood will be practically bone dry.
Paul,This has nothing to do with the title of this thread, but I can't find the one about wood moisture content and painting, so here I go.You responded 12-15% is fine for painting. I'm seeing 15% now, and hopefully it will get dryer still before painting.My question, if the primer is applied at less than 15%, then apply paint when conditions are good? No need to pierce primer coat, checking moisture content at that point?ThanksKevin
"No need to pierce primer coat, checking moisture content at that point?"
No Comprehend
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In other words check moisture prior to applying primer, no need to check it after that.
If conditions haven't changed in the meantime, it shouldn't matter. But if you have a moisture meter there anyway, why not test it again? The primer won't significantly affect the MC reading.
I probably will, just thought the primer stops paint from penetrating, so why check after primer goes on.
"house is on an island off New Jersey coast, 21 miles long by a few blocks wide. One block from ocean"
That's one big house! no wonder your getting help roofing it.
"house is on an island off New Jersey coast, 21 miles long by a few blocks wide. One block from ocean"That's one big house! no wonder your getting help roofing it.
--------------I don't know - after the first few miles you start to get into a rhythm...