# thermal break walls ?



## Windows on Wash (Aug 30, 2011)

Do you intend to do a complete thermal break of the walls or do you just want to insulate and air seal them?

What is the exterior of the home? You must pay special attention to the exterior and how it has breathed and lived to this point. Changing that dynamic can have disastrous consequences in some cases.

Thermally breaking the wall would involve some sort of staggered wall design or a rigid foam. Just properly insulating and air sealing the walls would be a considerable upgrade over the existing construction. Combine that with proper windows, attic air sealing and insulation, and you house will be 1000X better than before.


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## jklingel (Dec 21, 2008)

+1 for Windows. Maybe look at the simpler, big benefit options. As for "blow over this w/ ...." I'd use cellulose. It will sort of crust over and minimize wind washing. It is also fairly cheap, easily diy, and keeps bug/rodents out pretty well, assuming it is treated w/ borates. Just make sure you leave ventilation at the eaves.


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## Fix'n it (Mar 12, 2012)

Windows on Wash said:


> Do you intend to do a complete thermal break of the walls or do you just want to insulate and air seal them?


i was thinking that a complete staggered stud would be the best. but if all that extra work and expense will only get me a small increase over another method , i will look at the other methods. 



Windows on Wash said:


> What is the exterior of the home? You must pay special attention to the exterior and how it has breathed and lived to this point. Changing that dynamic can have disastrous consequences in some cases.


see pic. it seems to be some kind of asphalt shingle. idk yet what is under it. 
i would love to replace or cover it with new siding. but with the economy/my job, its looking like that will be a ways off, if ever. 



Windows on Wash said:


> Thermally breaking the wall would involve some sort of staggered wall design or a rigid foam. Just properly insulating and air sealing the walls would be a considerable upgrade over the existing construction. Combine that with proper windows, attic air sealing and insulation, and you house will be 1000X better than before.


1000x better would be great :thumbup:. but i have to keep it in budget.


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## Fix'n it (Mar 12, 2012)

jklingel said:


> +1 for Windows. Maybe look at the simpler, big benefit options. As for "blow over this w/ ...." I'd use cellulose. It will sort of crust over and minimize wind washing. It is also fairly cheap, easily diy, and keeps bug/rodents out pretty well, assuming it is treated w/ borates. Just make sure you leave ventilation at the eaves.


thanx. here is a pic of the attic . i am about 15' from the back behind me.
and iirc those are 2x4 joist . there are vents on the (5y/o ?) roof, but no soffit vents that i can find. i am thinking that that window in the pic is made to leak air.


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## jklingel (Dec 21, 2008)

This is easy. Blow cellulose over the whole attic as thick as is appropriate for your area (code + several inches). While you are ripping the inside up, be sure to think about air sealing the interior; all penetrations, wall plates, etc. As for double-studding the walls, if you can afford it, sure; even having the two walls separated by 2" would help immensely. Dense pack with cellulose or Spider fiberglass. If you leave the walls single and are re-siding, then you can get a good thermal break by installing exterior rigid foam. Greenbuildingadvisor.com has a good blog titled "How much exterior foam?" or something like that. Search there and you'll find what is recommended for your area vs how much insulation you have inside. Between the studs, if single wall, use Roxul mineral wool. New windows may or may not pay for themselves, but would likely improve comfort. They are spending, so maybe leave them for later.


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## Gary in WA (Mar 11, 2009)

Is that a paper/foil facing on the attic floor insulation?

Here is the one I use a lot, even has "best bang for the buck" comparison as well as moisture potential and thermal values: http://www.buildingscience.com/docu...walls-pacific-northwest-hygrothermal-analysis

Notice the rim joist areas in that article.... http://www.buildingscience.com/docu...joist/files/bscinfo_408_critical_seal_rev.pdf

Start by air sealing the basement to help stop the stack effect in your balloon framed walls: http://www.wag-aic.org/1999/WAG_99_baker.pdf

Gary


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## Fix'n it (Mar 12, 2012)

jklingel said:


> This is easy. Blow cellulose over the whole attic as thick as is appropriate for your area (code + several inches). While you are ripping the inside up, be sure to think about air sealing the interior; all penetrations, wall plates, etc. As for double-studding the walls, if you can afford it, sure; even having the two walls separated by 2" would help immensely. Dense pack with cellulose or Spider fiberglass. If you leave the walls single and are re-siding, then you can get a good thermal break by installing exterior rigid foam. Greenbuildingadvisor.com has a good blog titled "How much exterior foam?" or something like that. Search there and you'll find what is recommended for your area vs how much insulation you have inside. Between the studs, if single wall, use Roxul mineral wool. New windows may or may not pay for themselves, but would likely improve comfort. They are spending, so maybe leave them for later.


ok, cellulose it is. anyone estimate the cost for a 30'x36'x12" ? i will get the stuff from HD as they are the closest.

air sealing = of course. 
the cost for double studding. for a 24'x9' wall. that should be about $100 for the lumber ? i was planning to space it out 1". thoughts on this ?

seems to me that the insulation is going to be the most costly item. unless i can use something else if i do the double studs. 

this place HAS to have new windows. the current ones are BAD.


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## Fix'n it (Mar 12, 2012)

GBR in WA said:


> Is that a paper/foil facing on the attic floor insulation?
> 
> Here is the one I use a lot, even has "best bang for the buck" comparison as well as moisture potential and thermal values: http://www.buildingscience.com/docu...walls-pacific-northwest-hygrothermal-analysis
> 
> ...


yes, but idk which it is. i would go up there, but i have yet to bring my ladder here :whistling2:

thanx for the links. i just looked. the basement has bricks/mortar in front of the rim joist . though i am sure they are leaking a little.


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## Gary in WA (Mar 11, 2009)

With the brick at winter temp. and the solid wood rim R-value at R-1.25 per inch.....

Gary


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## Fix'n it (Mar 12, 2012)

do you think it would be a good idea to remove the brick and put in something else ? i have a small demolition hammer that should make short work of it. 

right now i am looking for new windows for the basement. as they are pretty bad. 

also, i am going to get a wood burning stove for down there. the basement is going to be a man cave, butt kickin home theater, pool table, shuffle board, etc.
so i could burn a fire for heat while hangin down there., to help save the gas bill.

this weekend i am going to get my ladder and go up in the attic to see what i am working with.


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## Fix'n it (Mar 12, 2012)

jklingel said:


> As for double-studding the walls, if you can afford it, sure; even having the two walls separated by 2" would help immensely.


when you say separated by 2". do you mean having the wall 2" thicker, or building another wall, separated by 2" ?

in this pic, the stud does not go to the bottom plate, because of the lower 2x4. i could do it like this. but i am thinking to just get 2x2's. 

i am still not decided if i should do this. even though it seems to make a LOT of sense.


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## Fix'n it (Mar 12, 2012)

oh. the original studs are 3 1/2" (when did they start going from "real" dimensional lumber, to downsized lumber ?).
and adding a 2x4 like this, will add 1 1/2", for a total of 5" for insulation. that is about a 45% increase.


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## rightit (Mar 5, 2011)

Fix'n it said:


> oh. the original studs are 3 1/2" (when did they start going from "real" dimensional lumber, to downsized lumber ?).
> and adding a 2x4 like this, will add 1 1/2", for a total of 5" for insulation. that is about a 45% increase.


If building a staggered wall, fir out 2" for a 5.5" wall (today's 2x6). This will correspond with insulation thicknesses. Also, remember that a staggered wall presents its own difficulties (as I learned by recent experience), one of which is insulating. 

I am assuming that you want to build a true 'staggered stud' wall and not just increase the wall depth by firring onto existing studs. A true staggered wall will provide a thermal break, as the inside wall is mechanically "decoupled" from the outside wall (sans minimal connecting points, i.e., at bottom and top plates):

http://www.soundproofingcompany.com/soundproofing-articles/staggered-stud-wall-construction/

As you can see from the above link, in addition to a thermal break, a staggered wall also helps to soundproof the space.

As to the insulation issue,the staggered wall will offset the cavities so that one 5.5" bat will not simply fit. Also, it was more work to properly insulate. Here is a link to a post describing those insulating issues and how I solved them by 'splitting' the bat. I used R-23 (5.5") Roxul stonewool:

http://www.diychatroom.com/f103/cutting-roxul-141545/

That said, foam would be a good, albeit more expensive way to insulate a staggered wall. Certainly less labor intensive.

Also, while you are airsealing in the open walls, don't forget to airseal the outlets. You could just caulk the wire entry points, but putty pads seal the enire box and do a great job against sound _and_ air.


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## Fix'n it (Mar 12, 2012)

yeah, i would stagger. but i would put the new stud right next to the old one.
not a perfect idea, but would work for me.

thanx for the 2" tip.


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## rightit (Mar 5, 2011)

Fix'n it said:


> yeah, i would stagger. but i would put the new stud right next to the old one.
> not a perfect idea, but would work for me.
> 
> thanx for the 2" tip.


That works, and may be easier to insulate. Just be sure not to allow the staggered stud to touch the existing stud or you diminish the thermal break.


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## Fix'n it (Mar 12, 2012)

rightit said:


> and may be easier to insulate.
> 
> Just be sure not to allow the staggered stud to touch the existing stud or you diminish the thermal break.


that is what i am thinking.

yes, i know. but it still would do pretty good.


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