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10 Answers

I'm getting two different opinions about foam insulation in the attic

Some say spray the roof deck-allowing the attic air to become conditioned which is great for the H&A ducts in the attic. Others say spray the attic side or the ceiling to allow the attic to vent. I don't understand this one since the attic air is now unconditioned air and the ducts a
have only a wrap of insulation..I'm confused. Sounds like there are two schools of thought going on. Are both ways OK? Is one a lot better than the other? Help!! I even heard that the house would be too tight and allow for stale air to remain in the house if you spray the roof deck..I need answers.

Asked By Rus Pearson | Sep 30 14
12 Answers

Please tell me why I have to put so much insulation / outsulation at the roof/celing?

This may be a stupid question.......... but, I am building a pretty passiv/aggresive house in Zone 3 and my mandated (code) R-values are as follows:

Ceiling R-value 30
Wood Frame Wall R-value 13
Mass Wall R-value i 5/8
Floor R-value 19
Basement Wall R-value c 5/13f
Slab R-value d, Depth 0
Crawlspace Wall R-value c 5/13
Fenestration U-Factor b 0.50j
Skylight U-Factor b 0.65
Glazed fenestration SHGC b, e 0.30

Asked By leo kloop | Sep 30 14
7 Answers

Proper Approach to Insulation Under Add-On Porch

We are moving into a house that has an enclosed porch area off the rear of the house. We assume it was once an open area that was later enclosed. It is now used as a pantry. Above the enclosure is a porch for the second level. The main home is solid brick (built 1910) and the porch enclosure appears to be wood framing with vinyl siding. It sits about 2 feet off the ground - e.g. you could walk under and see underneath to the joists. We haven't moved in but during the inspection I looked under and realized there was no insulation between the joists.

Asked By Historical Work | Nov 24 12
4 Answers

Improving R-value of 2x4 wall in renovation with interior foam board

Hi gang,

Doing a renovation in MA, USA, and I need a little help... There's a 2x4 wall that needs insulating, and I'm not redoing the exterior of the building. It would be easiest for me to get the wall dense-packed with cellulose, then go over the whole thing with 2" foil faced foam... but I have a couple questions...

Asked By Eric Nash | Sep 23 14
3 Answers

Old house with no sheathing/vapor barrier

I have an old house with no sheathing or vapor barrier, just clad siding on top of studs. I have the interior gutted and I am set to add batt insulation and new drywall back as it was originally. Should I add felt on top of the insulation and under sheetrock as a vapor barrier...still allowing the wall assembly to dry to the outside? or will it condesate on felt in summer and rot studs/etc.

ps I am in SC...really hot/humid.

Asked By charles elrod | Sep 25 14
4 Answers

Window coating confusion

I’m trying to figure the proper coating to order for my new windows for my renovation project, I was planning on triple pane windows from Ostaco windows. The house is located in Toronto, ON sits with the rear facing southeast, front northwest, the house has a fair number of large windows facing the rear, fewer on the front, no real tree shading in the rear, some red pines in the front, hoping to get wall insulation up to R40 range. The options are Low e 180 Low E2 272 and Low E3 366 all from Cardinal. Cardinal has a calculator for deciding but I would prefer input from others also.

Asked By Dave B | Sep 24 14
11 Answers

Proper way to insulate an old attic?

I am helping to insulate a friend's attic in Milwaukee, Climate Zone 6. The house is 100 years old, balloon frame with stucco. Attic floor is lathe and plaster. We would like to remove the fiberglass insulation, clean the attic floor, seal holes/top plate, then spray 2" closed cell spray foam to air seal the lathe and plaster. After that fill in blown cellulose to R-60.

Asked By Justin Lee | Sep 23 14
3 Answers

Insulation for dormer with thinner studs

I am in the process of building a small cabin in Climate zone 7-8. All the walls are 2x6 and I am planning on using Roxul to fill the stud bays. Exterior has no foam just 1/2 plywood and Tyvek. I will be installing a rainscreen and using some sort of cement board siding.

Asked By Andrew David | Sep 23 14
3 Answers

A layer of 1" XPS foam between fiberglass batts?

I live in MN and am working on a complete interior remodel. The exterior walls are 2"x6" w/ R19 fiberglass batt insulation, some with Kraft back & some with poly on the interior side. I would like to try & at least double the R value, but due to other design constraints would like to keep the additional interior intrusion to a minimum (exterior insulation is not possible).

Asked By Joshua Streblow | Sep 19 14
1 Answer

Insulating Cantilever Space Containing Water Pipes Zone 4A No. VA

I am wondering what is the best way to insulate a cantilever space containing hot/cold supply pipes and a bathroom exhaust vent. Above the cantilever is a bathroom, below is the entrance to my house and on the inside another bathroom. Currently there is only fiberglass, no blocking, no foam, no sealants. The pipes have been there since 1984 and since I live in a middle unit townhouse they will not be moved.

Asked By Alex Chandler | Sep 20 14
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