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Discussion Starter · #1 ·
A client of mine has a 1960s brick home standard crawlspace foundation. The client wants to insulate the home from the inside, she has no problem gutting the rooms with exterior walls. Insulating from the outside isn't an option, she doesn't want to disturb the brick. She wants some sound proofing but nothing expensive or major, just basically better than the old R11 fiberglass she has currently. Her main focus is insulation value, they want as much R-value as possible without the expense of spray foam. My current thoughts and proposals to her are as follows...

OPTION 1 - Insulate using denim R-15 batts followed by foil-faced polyiso 1.5" thick, then drywall.

OPTION 2 - Rip 2x4s in half, fasten to existing studs creating a deeper bay so that R-19 denim batts can be installed, followed by 1" political then drywall.

What do you guys think? Better options? Am I on the right track?
 

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If you're gutting, I'd consider blowing the walls, you'll get much less air movement through the wall. If you strap the wall out, putting extensions on all the windows and exterior doors isn't too difficult, but the electrical boxes may not have enough wire to be moved to the new wall plane.

If you run 2x2s or 2X3s horizontal to make the wall thicker you get less thermal bridging and you can shim the attachment points as you go to get the wall in plane, but you potentially have more air movement through the wall assembly.

Either way, get all penetrations air sealed while the wall is open.
 

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Sean
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Dittos with HDavis on essentially all counts, dense packed cellulose - make sure you take care of any moisture / flashing issues or it will cost you big time

The biggest issue really isn't the R-Value, it is air sealing & then installing the insulation properly especially as it relates to the attic

As for foil based poly - not worth the money (at least the foil) as you need to have an air gap for the radiant barrier to be of any use. Besides even if you had it on the right side it would be a waste as the brick with that air gap actually deals with that.
 

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Discussion Starter · #4 ·
The only reason i would be using foil faced poly is because of all the rigid foam in my area, it has the greatest R-value per inch. As for dense packed cellulose i immediately considered that option, the only thing keeping me from it is the client wants to work 1 room at a time because she will be living there at the time of the renovations. I have a guy in My area that does dense pack but will it cost me greatly to have him blow one room every 2 weeks as opposed to all at once?
 
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