I am north of the 49th parallel and want to know if anyone recommends not putting a poly vapour barrier on the basement walls. Mold?
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Two methods:
Poly in basements only up to grade level (bring poly under soleplate if possible)
or sprayfoam insulation between studs and concrete wall and seal all cavities at the same time.
BTW its always good to keep the studwall away from the concretewall to avoid wicking
I live close to the 49th and hope to redo the basement soon.
Our local code requires a VB, but after doing a lot of research (a lot in these forums) I've come to the conclusion that a VB in a basement is a bad idea if it's an older basement.
What I plan to eventually do is use EPS, sealed on the upper 4' of the wall, nothing below, steel studs, and then paperless sheetrock.
The EPS is based on some building science research done in Canada. I have the PDF "Basement Insulation Systems - Nathan Yost, MD, Joseph Lstiburek, PHD, PD" but I don't recall which web site I grabbed it from. I'll do some googling...
paperless sheetrock? Never heard of that. Are you in Minnesota? I am in Manitoba. What do you think of Tyvek as an air barrier? Your idea sounds goos to me though. What thickness of eps and what r-value?
"I hate quotations. Tell me what you know" Ralph Waldo Emerson
I'm in MN. Where in Manitoba are you from? (My mom's family is from up there).In our bath I just used the paperless stuff. It's DensGuard. Instead of paper, it's all fiberglass. Which means less likely to get mold, though it's a pain to work with (had itchy arms for weeks ;o)r-value is up to you, I guess. Our house is old, and no heat in the basement, so ANY insulation is going to be an improvement for us ;o)Most heat escapes from the upper exposed part of the foundation and only a few feet down (maybe deeper in Manitoba) so that's why I only plan on insulating the top part. We still get the occasional trickle of water in along the bottom of the wall, so I didn't want to trap that at all.My personal belief is that if it's an old basement, it will leak someday, so might as well design around that.We're going to sheetrock the upper part (densguard) then likely some sort of wainscotting along the bottom.
70612.6 in reply to 70612.5
I am in winnipeg and a client wants the basement done and i want them to know what their options are. That paperless stuff seems like it would be marine grade. I wonder if Home Depot sells it and what they would charge. Our frost line is 3' here, so probably five feet of basement wall would do it. Must be nice to have a NHL team!"I hate quotations. Tell me what you know" Ralph Waldo Emerson
Here's that PDF. Sorry I don't remember the site. It was a free download so hopefully I'm not breaking any rules by posting it here.Here's the paperless wallboard info:http://www.gp.com/build/product.aspx?pname=DensArmor%c2%ae+Plus+Interior+Wallboard&pid=4659&hierarchy=pcI assume Home Depot would have it.And yes, it's nice to have a NHL team back after loosing it to Texas, of all places. And while it's a great stadium, I do miss the days when you could walk up to the gate and still be able to get a seat for $10.
the last year the Jets were here the cheap seats were $16CDN for the nosebleeds. No wonder they left town. "I hate quotations. Tell me what you know" Ralph Waldo Emerson
Thanks for posting that. Very helpful. After reading it, I dug up the link if you ever need it for any reason.
http://www.washingtonco-op.com/pages/bisBSC.pdf#search='basement%20insulation%20systems'
"A job well done is its own reward. Now would you prefer to make the final payment by cash, check or Master Card?"
That comes from Building Sciencehttp://www.buildingscience.comLook under Resources.I see that it dated 2002 so I think that it has been updated.
I think the site that was referred to is http://www.buildingscience.com/
There is a lot of good information here, based on science and data, that should be read before making decisions about how to manage moisture.
Good luck.
"In God we trust; all others bring data."
We're working on a basement and had to rip out all the sheetrock that was installed in a basement without insulation or vb. Warm moist air condensed on the cool side of the sheetrock.
It only took 6 years for a nice even layer of black mold to develop on the lower 12" of all the rock.
I wouldn't build a 2x wall against a basement wall without a good vb. House wrap lets moisture through and isn't intended for the conditions in basements.
where are you located? Was there any chance the moisture was from dampness or a leak or the slab?
"I hate quotations. Tell me what you know" Ralph Waldo Emerson
where are you located? Was there any chance the moisture was from dampness or a leak or the slab?
That's what usually happens anywhere in the rocky mountain region. I've worked in high altitude areas that are quite cold and here in Boise, ID where it's dry as a popcorn fart much of the year.
All concrete will pass moisture into the house unless there is a moisture barrier on the outside and then you'll still get moisture coming from the footer. If it's an existing foundation you probably don't have moisture protection on all sides of your foundation.
I do like the idea of having ridgid foam behind a framed wall. Any warm moist air can't reach anything cold enough to condense on. Still, 6 mil poly is so cheap I'd still have that, then the ridig foam (sealed with housewrap tape), then the framing.
:-)
If you are only insulating part of the wall in Manitoba (not all of the way down) you are making a mistake energy and comfort-wise. Your electrical utility (Manitoba Hydro)has good guidelines for insulating basements in our climate which you should follow plus a program which will rebate the homeowner a big portion of your insulation material costs if you follow their guidelines (insulate copmletely top to bottom to R24). If you leave out a vapour barrier (whether XPS or closed cell spray foam or polyethylene over batt insulation) in our climate you are also making a big mistake. What kind of home is it? How tight is it? What is the foundation - stone or concrete? How high is the foundation above grade? How are you going to deal with the header? Has the house had an Energuide Energy Analysis done on it?
prairiehouse
I should mention that we're also not going to have airtight walls. Part of our plan is to make sure the back of the wall is fully vented to the inside space. Again, in an attempt to not trap any moisture back there. Yes, this isn't the most efficient method in terms of energy savings. That said, we're likely not going to heat the basement that much anyways (likely just be using a fireplace while someone is down there). Of course, living in MN with high-humidity in the summer, we'll also be running a dehumidifier full time.My understanding is that there are two schools of thought...block ALL moisture completely by using a full moisture barrier from mudsill down to floor, across slab, fully sealed OR no VB at all, and make sure whatever moisture gets in gets out. It seems as if the 'in-between' methods are what can cause the most problem. The older houses I've visited that have had a redone basement of the latter type still had a very musty feel to it...so it seems like a great method in theory, but perhaps really hard to implement completely fully sealed.Also, the less traditional sheetrock in the basement, the better, it seems.
i just don't see how there can be an effective vapour barrier when there are electric wires to cut around and also the joist bays to insulate inside of. So assuming i do put up a vapour barrier how do i seal around the furnace pipes and the hose bibs and all the other stuff. If the vapur barrier was improperly sealed in these spots would that not create MAJOR problems...could condensation or frost or whatever build up in those spots and melt and then mold etc. Seems maybe it would better to use XPS and the paperless DW so that it would be impervious to any moisture build up. Seems like the mold survives better when it has some paper to chew on...even the greenboard should be out. There will be small, small kids in this house and with the way kids' immune systems are these days i don't want to screw this up.
"I hate quotations. Tell me what you know" Ralph Waldo Emerson