Remodel / moisture barrier..Help?
I need some input on building in a climate that is much different than what I am used to.
Being offered a chance to head up to central Washington to do some total remodels on some old (1900-1930) wood frame houses. Mostly classic bungalow style stuff. Would be working with/for a large extended family on a number of old farm dwellings.
Climate there is much different than what I am used to (here it is cool and wet in the winter, there snow, cold and dry, summers here dry and moderate, summers there hot and very dry.).
Owner wants to keep the original sidings. ( It is in remarkably good shape)but wants to gut the interiors, insulate, re-wire/plumb/HVAC. windows, new roofing etc.)
All these old places have 1×6 diagonal sheathing and some type of either bevel or drop siding, no moisture barrier at all.
My questions are:
1) What (if anything) do you guys who remodel in cold dry climates do to install moisture barriers when doing this work? I would hate to remove and re-install the existing siding, hate even more covering it all up.
( My observation is that wood doesn’t easily rot in that climate.. I was stunned at how some very old roofless structures have lasted)
2) Vapor barriers for that climate. Where?
They can’t get your Goat if you don’t tell them where it is hidden.
Replies
vb goes on the warm side, so it's easy after a gut, insulate and then vb, of course we're all going to tell you to use spray foam to cut down on air pentration through the old siding ..
Vapor barrier I understand, my real issue is the moisture barrier.
They can't get your Goat if you don't tell them where it is hidden.
I think you're talking about housewrap/infiltration barrier, like Tyvek? If so, you can: 1) skip it and, preferably, use foam to insulate; 2) R&R the siding and add it underneath; or 3) install it from the inside.
I've done all three at various times, depending on what I was looking at. Option 3 is "interesting". While not as airtight, I think it helps & I've done it on structures that were sheathed with 1X and had brick veneer and in cases where there was wood siding with no sheathing. In those cases, infiltration was pretty severe, drastically reducing the effectiveness of the insulation. So I installed a continuous sheet of Tyvek from the inside, pushing into the stud cavities and getting it as tight as I could, prior to insulation. Not exactly air-tight, but a big improvement and about as good as you could get under the circumstances.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
Ahh terminology.... Yes I am talking moisture/ air infiltration barrier. Sorry, I should have used that term. I am accustomed to referring to it as a moisture barrier because of the weather here where I live. I know better , old habits die hard.
The I understand the vapor barrier application for that climate.
Average Dec/Jan temp there is 20F. Rainfall annual avg, is about 10" (8-12 spread in the region)depending on the micro climate.
The foam sounds like the best deal, short of stripping the old siding or overlaying it, whats your opinion on using dense pack cell? I have never worked with it.
They can't get your Goat if you don't tell them where it is hidden.
I love DP Cells. But if you decide to use it, you still might wanna install housewrap from the inside, depending on how wide the gaps are in the sheathing. Here's a pic of a dormer where I put the housewrap on the inside years ago, and recently stripped the siding to replace with felt/shingles. You can see the white wrap installed around the studs from the inside through the sheathing gaps.
This was a dormer that was sided with vinyl at the time. I blew in cells after the wrap and scrim was installed. Those gaps between the sheathing would have let a lot of cells blow out through 'em, which I wanted to avoid. (And this was a good section. The main 1X wall sheathing was gapped about 1/2" or more.) Worked well enough that I'd do it again in a similar situation.
View ImageMike HennessyPittsburgh, PAEverything fits, until you put glue on it.
Never thought of installing e.g. tyvek on the inside of the sheathing .... course part of it's job is bulk water shedding in the event you have e.g. wind blown rain get under the siding or someone pressure washes the house or whatever.
"course part of it's job is bulk water shedding "
Yep, and that's a part that just doesn't get done if it's put on from the inside. But most of the structures I've worked on are 70+ years old, and have relied on pre-tyvek methods to successfully keep water out, e.g., true shiplap, drainage planes behind masonry, etc. Those methods worked well in the days of cheap energy &/or lower interior temperatures and still work well, if done properly, for water issues. In fact, I just can't bring myself to think of Tyvek as flashing like many seem to.
These methods just don't touch infiltration, tho'. So if you've got infiltration problems (and what old house doesn't?) and you don't wanna (or can't, like in a historic district) re-do the siding, a guy's gotta do what a guy's gotta do! ;-)
Like most restoration solutions, it's a workaround and not perfect, but it does help. Enough to make it worth the cost of the wrap anyway, if the walls are otherwise opened up.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
That is absolutely right. Good points.
#1 paint
#2 VB inside studs
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The interior I understand , may even have a chance to try some blown in cells/spray foam if it is available in that area. Need to do some research on what the situation is in terms of building suppliers/supplies and subs. You would just leave the exterior as is then/ Good caulking job and good paint job and let it be.
That is along the lines of what I was thinking but not accustomed to the different climate I wasn't sure and wanted to hear what those who have remodeled in that type climate had to say.
They can't get your Goat if you don't tell them where it is hidden.
Vapor RETARDER ... goes on the warm side (e.g. under drywall and over insulation). I disagree about your climate assessment. The NW is cold and wet in the winter. Average temps in winter around 34 degF. Cold and dry is e.g. East of the Rockies (e.g. Montana and upper midwest). I lived in that neck of the woods for 20+ years. Snows ... then Chinook winds melt it ... or it simply just rains instead ... miserable.
Sounds like you have a wall that breathes well. Should have little moisture vapor issues. The bulk water would be the only concern, but you ain't in the gulf coast where it often rains horizontally :)
Not even felt paper under the siding? If you reside, felt or Tyvek would be logical options. With that construction, seems like just the ticket for Tyvek to control air leakage more.
I should have used the term air infiltration barrier, not moisture barrier. I know better , just slipped into old habits.
So Yes, Tyvec or equivalent(which I hate, rather use 15# felt) Don't know where you lived in the PNW but within 60 miles of me there are at least 3 major climate regions. The location I am talking about averages 10" of rain a year, Dec./Jan high temps avg. 20 F. Dry Powder snow.
Where I live I get 60 " of rain and Dec/Jan avg. temps of about 38F.
They can't get your Goat if you don't tell them where it is hidden.
10" of rain ain't much for the NW. I've stomped around Spokane, Hood River, Seattle/Portland ... fairly large variations in rain, but non of those are low as 10" (although maybe the Tri Cities is lower than Spokane).
I used 15# felt in Hood River w/out regrets. OSB/plywood make great air barriers so the benefits of tyvek has been arguable. Not saying it's not a good product. With plywood and felt, not sure if you gain a lot by spending several hundred dollars more in many applications where you have the continuous sheathing.
Sorry ... forgot you had board sheathing ... tyvek is perfect for that if you have a chance to 'sneak it in under the siding' :) I'd say if there is a very good application for tyvek, one would be the old board sheathing.
Edited 9/10/2009 8:24 am ET by Clewless1