Crawlspace Insul. Open or closed cell?
We have an encapsulated crawlspace where we just insulated the CMU block walls and rim board. Our insulation contractor sprayed and swears by open cell. However, it is wicking water and is holding the water like a sponge. Is there anybody who has third-party info for the correct insulation to spray in an encapsulated crawl?
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I'm just sayin'
If open cell is wicking water and holding water like a sponge I would think that the obvious is the insulation is not working. Change to closed cell, but then that is all that I use.
Well obviously...I guess I would just like to see third party information explaining why open cell shouldn't be used in the crawl space. We are definitely going to remove the OC and replace. If the insulation is going to wick and hold water... why is it better than fiberglass? Closed cell will not wick the water...right? So why in a moisture prone area would somebody insulate with a sponge? Common sense tells you that you wouldn't do it...but that doesn't hold up in court.
OC foam does not wick moisture out of the air.Again where is it coming come.While closed cell will not absorb water it is not designed to seal off water either..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Sounds like you're looking for an 'expert witness' of some sort to back your position in a lawsuit against the insulation sub.
The problem is that it's either the Archy or the GC who's responsible for the choice of materials. Failing an architect's specification, the insulation sub may suggest a product but it's the GC who decides what he uses.
So who was the GC?
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Where is the water coming from? That is the question.
Properly used there should not be any problem with OC foam.
And while it CS will not absorb water like OC will it is not a water proofing agent.
And water pressure will end up "breaking through".
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Open cell isn't a vapour retarder on it's own. I believe you can paint it with latex, which will make act as a vapour retarder( possibly barrier).
Closed cell inherently retards vapour so no moist air will get through to the point in the insulation where it is cold enough to condense. That said I'm not sure where you are located geographically, but it is pretty early in the Fall/Winter to be noticing a moisture condensation build-up in your OC insulation unless of course your crawlspace is particularly humid.
Is the crawlspace ventilated? It should be if you have encapsulated it(sealed it up). It is now, essentially, a very well sealed interior space, so moisture has nowhere to go.
As always the best reference for this stuff is Building Science...
http://www.buildingscience.com/index_html
Why take the word of your insulation contractor? What's the likelihood that he has a good understanding of Building Science?
My experience has been that most contractor's have a very limited grasp of building science, especially the one's who should. It's the nature of the construction business, you're paid for the task you do, not your knowledge of building science.
Ultimately the designer/builder/general contractor has to take responsibility for the materials used in the building, and their relationship to each other. I no longer expect the trades to provide reliable information with respect to building science best practices, it will lead to disappointment. That's not to say their aren't any contractor's who aren't very knowledgeable about building science, but how are you going to know if you haven't done your own research.
Things might change if we moved to an integrated design approach to building/renovating homes.
http://www.sbc.nrcan.gc.ca/buildings/pdfs/IDP_overview.pdf
That's my Friday afternoon rant after what is approaching two years from design to (almost) completion of an addition/renovation of an energy efficient home. I'm a little punch drunk at the moment.
Cheers,
Andrew
P.S. Attached is a photo of the house last winter. We were ten centimetres short of the yearly record snow fall last winter, something like twelve feet. Not much useful got done on the house last winter.
Sorry about going off on a tangent, don't want to hijack this thread.
If the crawl is encapsulated, why is it wet?
Family.....They're always there when they need you.
There's a great new article about crawlspaces at the Building Science Corporation website entitled "new light in crawlspaces". Given your situation, this info would be very relevant. Insulation doesn't cause moisture problems. Water causes moisture problems.