# Home Renovation - What to do about insulation



## benking (Aug 7, 2008)

Later this month I'm gutting the upstairs of my cape and removing most of the roof to add two full shed dormers.  I'm on the fence regarding insulation.  I have three main options, std. pink batts, blown in insulation and spray foam (closed cell).  

Spray foam is way more expensive but has some strengths as far as keeping a home sealed and warm.  Air exchange, price, moisture and bowing windows / walls are the main issues.

I was leaning towards spray foam but I'm a bit concerned mainly about moisture issues and air exchange.  Anyone have any personal experience.  The guy doing the framing says he always uses the pink stuff but because I'm taking this down to the studs I want to plan for the future.  Its cold here in Maine and a tight house is nice as far as heating costs go.

Anyone have experience with Spray Foam?  What are people in similar situations doing?

Thanks for you're help.


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## sinnian (Aug 7, 2008)

I don't understand, 'foam' is moisture proof.  What is you issue with it?


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## tkirk22 (Aug 8, 2008)

Another option is 1" of spray foam and then  conventional fiberglass. The foam will act as a vapor barrier and block air movement before it reaches the glass insulation.

There is no chance of bowing anything as long as the foam isn't confined as it expands. In your case if you take everything down to the studs there will be no problem.


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## benking (Aug 8, 2008)

The concern about moisture is from the inside of the house.  It has no route to escape.  I have no cenral HVAC system so the only vents would essentially be bathroom fans and (sealed) soffit vents.  Has anyone here gone the 1" of closed cell foam route with FG batts or blow in on top?


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## benking (Aug 8, 2008)

Current exterior wall from what I can tell is 1x sheathing with a possible tar paper, clapboard siding which was then covered in vinyl.  I'll be removing the vinyl and clapboard from the house and replacing it with untreated cedar shingles.  I'm also exploring the idea of putting rigid foil faced foam (1") under the cedar around the whole house.


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## mbcijim (Aug 11, 2008)

Kirk22 said:
			
		

> Another option is 1" of spray foam and then  conventional fiberglass. The foam will act as a vapor barrier and block air movement before it reaches the glass insulation.
> 
> There is no chance of bowing anything as long as the foam isn't confined as it expands. In your case if you take everything down to the studs there will be no problem.



I'm doing this now, to my house currently under construction.  2x6" construction.  1/2" spray foam and R-19 fiberglass batts.  

Here's my reasons:
1.  Spray foam seals the house up
2.  Fiberglass way cheaper than spray foam.


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## wenger7446 (Aug 11, 2008)

I just finished an addition on my home and did the spray foam insulation.  It was much more then the fiberglass batt but it seems the house is sealed much better.  I haven't had the project finished long enough to develop a energy consumption track record. 

If i were you I would go with the spray foam. 

my 2 cents. 

Ryan from Philly.


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## caber (Aug 11, 2008)

We're building our addition now with 2x6 studs and have been debating what to do insulation-wise.  Originally we were debating batts versus blown-in.  Then we saw on the Green Network a house using the expanding spray foam and it really seems to be a better option.  Depending on the price, of course.  

So, anyone know the diff in price?  and did you hire out or do it yourself.  I've found some diy kit options on the web that seem reasonable. 

thanks


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## begreen (Aug 11, 2008)

If you really want to stop the cold, a staggered 2 x 4 system is excellent for stopping transmissive heat loss through the studs. But the best alternative is often to put a layer of exterior insulation sheething on the outside of the house, right after the membrane.


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## Red Sun (Aug 11, 2008)

If the siding is usable and is also compatible with insulation underlayment it would then add r value to the siding. R value in the siding is likely a critical factor. 

http://www.fullback.com/index.php

Spray Foam

http://store.contractor-pro.com/foam-sealants-dow-2component-foam-c-19_102.html

eBay

http://cgi.ebay.com/NEW-TOUCHNSEAL-...ryZ63894QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Radiant Barrier FOIL 

http://cgi.ebay.com/Radiant-GUARD-R...ryZ63894QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


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## wenger7446 (Aug 12, 2008)

Our sprayed foam insulation was twice the cost of batt. 

$700.00 for spray foam to $375.00 for batt for 145 sqft. (lots of windows and doors in the room.) 

Ryan


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## Hogwildz (Aug 12, 2008)

When installing the insulation behind the siding. I suggest not using the foil faced on the sunny side of the home.
It bakes the underside of the siding. This is especially bad when using vinyl siding.


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