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4 Answers

Mineral wool in an attic


This is a complete newbie question.

I read the article about Mineral Wool in Fine Homebuilding 254 (pp. 48-53 September 16, 2015) and it says that if you use it for insulating the floor of an unconditioned attic, you need to use a vapor barrier underneath it.

Would the painted drywall ceiling in the living space below the attic perform that function or do I need to install something in each rafter bay before putting in the mineral wool? Would that thin bubble-wrap-like insulation sheeting work?



Asked By George | Nov 25 15
1 Answer

Inward solar vapor drive with Zip R Sheathing

I am curious if Zip R sheathing would experience any issue with inward solar vapor drive.

We have an upcoming project that will use Zip R Sheathing (in the polyiso 1 1/2" variety) - and will also have a reservoir cladding - stone on the exterior. There will be a minimum 1/2" gap between the back of the stone and the zip - but it won't be ventilated. Still I was curious if the zip coating and osb might allow vapor to be driven through them only to condense at the outside of the polyiso.

Asked By Patrick Kelly-Decker | Nov 25 15
2 Answers

Vinyl siding over rigid insulation

I have a multi family project that needs to be resided. Unfortunately we cannot afford to use cement board siding and are using vinyl. Is it possible to attach vinyl directly over rigid anchoring to the sheathing? It doesn't seem to be an acceptable attachment method from the vinyl siding manufacturers. Is it worth installing sheathing over the rigid, perhaps a taped zip system? Thanks.

Asked By Julie | Nov 25 15
4 Answers

Builidng a house from the "Affordable Passive Solar Planbook for North Carolina"

I have the opportunity to possibly build a new house on a piece of farmland. I'm trying to keep the costs down, and I really want to incorporate ways to reduce build cost and future cost of heating the home. I'm in Calgary, Alberta.

Asked By Solange Pomerleau | Nov 24 15
4 Answers

Split system location

If I am going to install a mini-split in a very small, well sealed, well-insulated new home that will need airconditioning rarely (maybe never) but heat more often, does it make sense to install the interior unit at floor level instead of ceiling level? Is there generally an option offered by mfgr of low or high mounted units?

Asked By A Lange | Nov 24 15
5 Answers

Exterior Roxul batt insulation in semi-conditioned space?

I'm building a 10x14 timber frame shed in upstate NY climate zone 5. It's under 144 sq.ft. so doesn't require building permits or inspection. I have pine 2x T&G roofing and 1x wall cladding from a local mill. The building will be used occasionally as a workshop, including during winter. For this reason I'd like to insulate it. I'm grumpy about foam for various reasons including rampant carpenter ants around my property and so would like to use rock wool.

Asked By Michael | Nov 23 15
9 Answers

Spray foam and Roxul for flash and batt?

Hey guys,

I am in the process of finishing my attached garage in zone 5a. It will not be heated year round, just when I am working in there. When it will be heated, I will be using a 240v 6k watt electric heater.

I am torn on how to go about insulating my unvented cathedral roof. I ready that fiberglass batts against the sheathing are a no no but what about roxul? If that's no good either, can I just spray 2" of closed cell and fill with roxul then sheet rock?

Asked By Steve | Nov 23 15
48 Answers

Buyer education versus a good code and intensive enforcement of it

This is kind of a general question. I'm seeing more and more issues coming up on GBA questions and answers regarding shoddy construction that homeowners are having to deal with. I read it recently in Peter L's description of some builders in the Phoenix area. This is most concerning when one is having a new home built, or purchasing a previously built new home, and it has subpar construction.

Asked By Eric Habegger | Jul 21 15
1 Answer

At what temperature should blown foam insulation be installed on a steel roof with 2x6 trusses?

I have a 24x60 pole barn and want to keep moisture from dripping on inside items. It`s getting cold and I want to know at what temperature should blown foam insulation be installed? I`am more concerned with moisture than R value but plan on having 4 inches blown on the roof.

Asked By Gordon | Nov 24 15
2 Answers

Brick veneer air gap vents into rim joist in crawlspace/basement

50's rambler with a few additions over the years.
I believe it is cement board siding with brick veneer around the lower base.
Blower door test came in around 4,500 cfm50

Asked By B D | Nov 24 15
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