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1 Answer

Sealing up gaps in OSB exterior sheathing before insulating stud cavities?

My OSB sheathing on the exterior side of my exterior walls has many a gaps varrying from 1/8" to 1/4" as the proper installation instructions require the sheathing to be gapped with a nail to allow expansion due to humidity changes.

So...I'm looking at these gaps (some rather large) and getting ready to stuff mineral wool in. Should I take any time now to a.) caulk or b.) spray foam these gaps? I have a decent house wrap over the sheathing of course but that doesn't stop everything.

In Green building techniques | Asked By Nicholas C | Oct 13 17
5 Answers

Insulate basement ceiling?

Good morning everyone. Contractor is suggesting dense pack cellulose in conditioned basement (basement finishing job). Walls are insulated with cellulose/sprayfoam on concrete. Is this advisable? I've read not to insulate basement ceilings. Will it make it warmer in the winter? I'm in zone 6. This will obviously also help with sound dampening. Alternatives?

In Energy efficiency and durability | Asked By gi4ever | Oct 11 17
6 Answers

Flash & Batt Roof or Open Cell over Closed Cell roof assembly

I am building a 2000 SF house in Boston, Zone 5 with an unvented roof. In previous homes I have used 7" of closed cell foam. In an effort to provide a more economical hot roof,I am proposing to use 3" of closed cell foam applied to the underside of the sheathing and using an unfaced fiberglass batt below that with no drywall attached. My insulation subcontractor is proposing 3" of closed cell and then the remainder filled with open cell foam to achieve the R-value. Would either of these assemblies be safe or is it best to stay with the full thickness of closed cell foam?

In Energy efficiency and durability | Asked By Matt Murphy | Oct 12 17
15 Answers

Marine Zone 4 — Wall insulation — addition

Zone: Marine 4
Location: Seattle, WA
House Built: 1915
Square footage: 900 ft2 single story with 900 ft2 finished basement.
Wall height over basement: 12 ft
Current siding: Cedar, Paint in poor condition.
Insulation: not much, some fiberglass bat stuffed in nooks and crannies as they opened walls in the past. And dirty so there is plenty of air gaps.

GOAL: Comfort

In Plans Review | Asked By User-6933356 | Oct 11 17
9 Answers

Should I insulate between outer block and inner stud walls?

Like so many others, I have been given conflicting advice from "experts" in the insulation industry and I am now completely confused. I am building a two story home in zone 3 (montgomery, alabama). The external walls were done with concrete masonry units with cavity's filled with pumped mortar. We then came to the inside and completely framed leaving 1/2 inch gap between framing and exterior block walls. We eventually plan to coat exterior of block walls with spray on portland, but that could be in all honesty at least a year down the road.

In Energy efficiency and durability | Asked By IndenturedContractor | Oct 13 17
14 Answers

Who has a favorite heat-pump water heater?

We are now underway with our "pretty good" house here in southern Oregon and I am committed to the hybrid heat pump water heater concept for our 2100 sq ft, three generation house. With four adults and a grandchild in the house, I felt that an 80 gallon unit would be desirable. We plan to locate the HPWH in a centrally located laundry room which is just under 700 cubic feet and have plumbed a floor drain into that room for condensate or tank failure (hope NOT). I had been inclined to go with the GE GeoSpring but I have heard a rumor that GE is going to discontinue manufacture.

In Green products and materials | Asked By Alan Hart-McArthur | Oct 13 16
62 Answers

Another crawl space in the Northwest

Hello all, I have a 1150 sq ft rambler house in Fall City, Washington (near Seattle), zone marine 4c. I am currently in the process of redoing the crawl space. I have pulled the damaged and rodent infested insulation down, and removed the town vapor barrier. It seems I had some rodents that were digging past the foundation and getting into the crawlspace, ruining everything.

In Energy efficiency and durability | Asked By David Meyer | Nov 28 16
2 Answers

What type of horizontal purlin/furring under my metal roof?

I'm agonizing over what to use under my metal roofing. I need something that will lie over my two layers of foamboard to take screws for attachment to rafters and also something to attach my exposed fastener metal panels to.

I'd like to avoid adding another 1.5" using 2x4 but most furring strips I'm finding are total garbage and only come in 8' lengths. Originally, I had planned on using 1/2" OSB or plywood, but that will be very expensive and wont allow me to shim out any sags easily. I wish there was some affordable synthetic material I could use.

In General questions | Asked By Dielectricunion | Oct 13 17
1 Answer

Need some structural advice for my 4x4 loft frame.


Here again, with another question for my tiny house. This time, it has to do with the design for my lofts.

I will have two lofts (one for sleeping and one for storage)..so each loft should never have more than 500 lbs on top of it. My walls are framed with 2x4's and I also attached a few pictures that I dug up for reference. The picture with the 2x4 beam is just a mockup to show the height of the loft. The picture of the underside of the loft is what I am aiming to achieve.

In Energy efficiency and durability | Asked By Grey Wolf | Oct 12 17
1 Answer

Under slab vapor barrier at two levels

I am retro fitting a existing slab on grade barn into a home , in order to accommodate plumbing, the run of the stairs and other , I am raising the floor. 2 to 4 inches of sand will be added followed by 3 inches of reclaimed XPS , then a 4 inch stained concrete finished floor. Typically I would top the foam with a vapor barrier, however there is a vapor barrier under the slab now. So I wonder if having 2 vapor barriers separated by the original concrete , sand , and foam creates a problem. Basically the sand and any moisture in lower concrete never dries out..

In Green building techniques | Asked By scott mangold | Oct 12 17
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