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6 Answers

If I use Zip R sheathing against 2x6 framing with rock wool, will we get condensation on the interior face of the Zip panel?

We are planning cabin construction in northwest Montana. We debated rigid foam sheets with housewrap but are leaning toward Zip R sheathing with 2 inch foam backing.

With the waterproof barrier integrated with the Zip system we are concerned that there may be condensation on the interior face of the panel. Is this a concern and how would it be handled? Would this dry to the inside?

In Green building techniques | Asked By Stephen Herbaly | Jan 8 17
10 Answers

Vapor barrier inside double stud wall — is this OK?

I’m building an energy efficient house this spring 25 miles Northwest of Minneapolis in the upper portion of zone 6. My wall design plan since the ’80s has been a double 2x4 stud with the vapor/air barrier in the gap between the two walls. This is similar to Joe Lstiburek's Ideal Double-Stud Wall Design with 2 taped layers of 1.5” Foil Faced Polyisocyanurate foam board replacing the ½” OSB in Joe’s design. I believe this design would keep the inside polyiso vapor barrier well above dew point under the most demanding winter conditions.

In GBA Pro help | Asked By Jim Sweazey | Jan 8 17
5 Answers

Mini-split for winter heating

My family has an insulated vacation cabin that is used in he winter ( zone 6
A). Normally it is heated via wood stove. Would it be possible (and smart ) to maintain the temperature of the cabin a 40F to 50F when not in use using a mini split heat pump. If the set pt is 50F what would be an estimate of the COP at outside temperatures of 40F, 30, 20, 10, 0, -10.
The cabin requires 9000 btus/Hr with an inside temp of 70F and outside temp of 0F. Would a floor mounted inside exchanger be better than a ceiling mounted unit? Currently when not in use the cabin is unheated.
Thanks, MainePaul

In Mechanicals | Asked By Paul Geisler | Jan 8 17
2 Answers

Tongue-and-groove OSB over 3/4" foam problem

I'm helping a friend with a basement remodel..
Winnipeg, Manitoba Canada zone 7.
1040 sq/ft basement, concrete walls and floor. no exterior insulation.

We are gluing (PL300) 2.5 inches EPS foam to interior walls. Then 2x4 walls (24" o/c) with R14 Roxul, no poly then drywall). The wall foam is bonded to the floor foam with spray foam in a can. The corners and seams are all taped. The top will be foamed with a froth pack to seal against rim joists.

Laid 3/4" foam to floors (is this supposed to be glued to the floor as well (PL300)?
The floor is not perfectly level but pretty good.

In Green building techniques | Asked By Tim Brown | Jan 9 17
1 Answer

Substitute for acoustical sealant?

I'm in possession of a box of Tremco TremPro JS-773 sealant. It's a one-part, non-skinning synthetic butyl sealant. When I got the box of sealant (a while ago), I thought is was acoustical sealant that I could use for attic air-sealing and such. The key feature is that it's supposed to stay somewhat gooey and not crack like most caulk does eventually. But of course it also has to attach to the bonding surfaces, which would be wood and/or drywall in this case.

In Energy efficiency and durability | Asked By andrew c | Jan 7 17
5 Answers

Green building concepts and expanded polystyrene

Hi, Thank you for adding me to this professional community. Expanded polystyrene and green concepts.

Hi, I am expecting experts advice on the Green side of expanded polystyrene (EPS) building materials. Currently, I am working here in the Middle East in a construction company.
Most of the works here are completed with one or other forms of polystyrene or other Styro varients. I need to know more about the Green concepts behind expanded polystyrene building materials.

In Green products and materials | Asked By Rich Scout | Jan 5 17
9 Answers

Dual problem - Frost in attic / condensation in range hood pipe

I will try to keep this as simple and brief as possible.
Central KY
Daytime temps in 20's - F
Nighttime tems in single digits - F
5:12 Roof asphalt shiingles - osb roof deck
Vented ridgecap (confirmed open and properly installed)
Full vented soffit with baffles to allow insulation
18" fiberglass blown in attic
all ceiling penetrations are airsealed with foam/caulk
2yr old house 2000square ft
RH = stays around 48%
Use bathroom vents on timer (soffit vented) religously
*Use RANGEHOOD VENT religiously when cooking (broan 634 roof vent)

In General questions | Asked By Jay Mack | Jan 8 17
4 Answers

How do I build the perfect wall?

I am currently designing a house that I plan to build in the next few years. This house will be my retirement home so It needs to be comfortable and energy efficient. It is a simple 1300sf house plan that will be built in Tulsa, OK.

Attached is the picture of what I have planned now, it is based on multiple designs I have found on-line. Any suggestions on how I can make it better or things I need to change?

In Green building techniques | Asked By Steven Slice | Jan 8 17
1 Answer

Peel-and-stick products

I'm planning to renovate and add on to my house using an exterior insulation method (Central New York, zone 5). I plan to use REMOTE guidelines as basis of design and plan to use peel and stick membranes for waterproofing, air/water barriers and drying in protection at following location,s and I'd like some input re: specific products some of you have been pleased with (and offer best value):

In Green building techniques | Asked By Joel Cheely | Jan 8 17
5 Answers

Owens-Corning mineral wool compared to Roxul Comfortboard?


I've noticed that our local building supply store carries Owens-Corning R-16.8 "Safing Fire-Stopping Mineral Wool Insulation". At a 4" thickness, that's something like R-4.2/inch.

In comparison, Roxul Comfortboard 80 R-6 48-sq ft Unfaced Rock Wool Batt Insulation with Sound Barrier (24-in W x 48-in L) (This is their 1.5" thick Comfortboard) is R-4 per inch.

In Green products and materials | Asked By Matt Gauger | Jan 7 17
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