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Need advice on remodel and insulation

Thanks, in advance for you advice.
I live on South Dakota, Iowa and Nebraska board, so we have 98 degree days and -20 degree days. quite a spread.
I live in my dream home and it is small, a 1940 built 44 x 24 on basement with attached 8 x 10 on crawl space.
Im going to be redoing the single pain windows and with either triple or double Anderson Renewal windows and major interior work and replacing doors. and since I have to rip out interior walls and replace the windows and remove the dumb bells I figure I should just gut the old plaster and replace the drywall and do the insulation, I do not plan on doing the siding for another few years due to budget.
The walls did have blown in insulation done back in 1980 and was resided with foam board, so I believe replacing the windows would be the first place to save on energy, but since I'm doing the windows I might as well do the rest and it is a small house.
So what type of insulation, Batts, spray foam, foam board any help on with this would be great.
I want to prevent condensation and air gaps.


Re: Need advice on remodel and insulation

A lot depends on what was blown into the walls in the first place. If it was cellulose, rockwool, or fiberglass, it may have settled. You can pull it out and replace it with faced batts or you can just add more loose fill to fill in the voids and cover with a 6 mil vinyl vapor barrier.

If you go with faced batts, place the wings over the ends of the studs, not to the inside face of the studs as commonly done. The wings should overlap a little, staple in place.

A little history here, the first faced fiberglass batts were R-7, 2.75" thick and had a bright foil face with paper wings. It was meant to work with foil faced sheetrock. The two shiny foil faces facing each other with a 3/4" air space gave an additional R-3 to the wall. That insulation is no longer available but the practice of stapling the wings to the inside face of the stud to give a 3/4" air space to the insulation is still practiced today, even though it is wrong for todays faced insulation.

Todays faced insulation is brown paper with a tar impregnation to make a vapor barrier and is 3.5" thick. It is not meant to have an air space between the sheet rock and the paper. The vapor barrier should be as continuous as possible so it should be stapled to the ends of the studs and overlap a little. The pressure of the sheet rock will close up the gaps.

But if you have a foam that was sprayed into the walls, there isn't much you can do. The stuff is near impossible to remove. Just look for voids and fill them in with more foam. If there aren't many gaps, the expanding foam in a can should work fine, even though it probably won't be the same type of foam. If the gaps are large, you may need a contractor to come out and fill them or you could just stuff in some fiberglass batting. If you use batting, be sure to cover the area with some type of vapor barrier like the 6 mil plastic or maybe even some facing from faced batts. Just make sure the vapor barrier overlaps the studs on the sides and a good foot or two top to bottom from the void.

Use the minimally expanding foam around the new windows and the new doors. If security might be an issue, use the triple pane glass and fill the gaps around the doors with hardwood filler strips in the lock area and the hinges. I like to use 2' long fillers around the top and bottom hinges and a 4' filler around the locks. Glue the wood in place, then screw with stainless steel 3.5" screws or ceramic coated deck screws, or hammer in 16d nails. Use the long screws in the hinges and the lock strike plates.

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