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9 Answers

Double stud wall sheathing / air sealing

Hi All,

Thanks in advance for any suggestions/comments/advice.

I am in the framing stage of residential home in central NC (Zone 4A). The exterior walls have been designed as a double-stud 2x4 assembly.

The interior double stud has been spec'd to be sheathed with 1/2 in CDX w/ taped joints and r-15 Roxul batts, cavity insulation as dense-pack cellulose to r-20, and exterior double stud finished off with another 1/2in CDX, followed by WRB, 1/2" vertical furring for rainscreen, 3/8" horizontal furring (to accomodate for Hardie board and batt siding.

Asked By Corcakalaka | May 22 18
7 Answers

Spray foam questions

Hello all, thanks for any help in advanced.

Asked By Stanger133 | May 20 18
39 Answers

Please critique my floor plans (first draft)

This house build is in rural Southwestern New Hampshire. 1500sq ft ish. 2 story, 2 bedroom, no basement. Site is south-facing Hillside. House will be on the north edge of a 2 acre clearing. Site has really good exposure for PV panels.

Shooting for Net Zero with PV Solar array on garage (11kw ish)
Double stud wall construction
ZIP system sheathing
Very tight air sealing details (with a blower door test)
variable permeance interior vapor retarder--- Pro Clima Intello Plus
R20 floor, R40 wall, R60 ceiling
dense pack cellulose insulation (walls, roof)

Asked By Tech1234 | May 17 18
2 Answers

Spray Foam Unvented Ceiling

Hello, new to this forum and I've seen a lot of good information in what I've read so far. Hoping to get some advice on how to insulate a ceiling in a detached office/accessory building on the Oregon Coast. I rebuilt an old garage and created a single pitch 2:12 unvented ceiling. Rafters are 2x10, uninsulated metal roof on top. I was planning to spray foam 2" of closed cell in the ceiling cavity. My question is do I need to fill the remaining cavity with batt or something else or could I leave 7 1/2 inch gap between the foam and sheet rock?

Asked By Dan McGuire | May 22 18
0 Answers

1 1/2 storey Framhouse in BC

Hi, I'm looking for some thoughts on our current design for our 2000 sqft home.

Asked By Michael Blake | May 22 18
6 Answers

Ecodrain Drain Water Heat Recovery

I first learned about Drain Water Heat Recovery pipes here on GBA and wanted to give back a very small token of appreciation in a short review.

I recently ordered and installed Ecodrain's V1000 and have been quite impressed with it. It's near the top of the CSA B55.1 list for highest efficiency and the price is quite reasonable:
3-inch diameter models:

VT1000-3-36 .......... $469
VT1000-3-48 .......... $524--my model
VT1000-3-60 .......... $564
VT1000-3-72 .......... $614

4-inch diameter models:

VT1000-4-36 .......... $549
VT1000-4-48 .......... $644

Asked By pat beurskens | May 22 18
2 Answers

Merits of removing masonry chimney?

Hi all,

The sixty year old chimney at my 50s ranch is severely damaged from moisture kicked off by our hot-water heater (now replaced with an indirect WH off our boiler). I've received several bids to have it rebuilt but I have a different idea. I am thinking of tearing down the chimney to below the roofline, insert a round metal chimney vent in its place, and finally roof & CC sprayfoam the cavity left behind. Rather than a 6' by 3' chimney I'd then only have two 6" metal pipes (basement & 1st floor fireplaces). The chimney is in the back of the house and adds nothing aesthetic.

Asked By Brian Gray | May 22 18
0 Answers

Fasteners for concrete, brick, and CMUs

For an upcoming article on fastening various materials to concrete walls, brick walls, and CMU walls, I'd like to hear about your favorite fasteners.

I'm looking at fastening three types of materials:
1. 1x4 furring strips directly to a concrete wall, brick wall, or CMU wall.
2. 2x4 furring strips directly to a concrete wall, brick wall, or CMU wall.
3. Continuous rigid foam (2 inches thick or more) directly to a concrete wall, brick wall, or CMU wall.

I will also look at a fourth situation:

Asked By Martin Holladay | May 22 18
0 Answers

Difficulty finding a modulating multi-zone air-source heat pump

I need to finalize the equipment selection for my current build. My engineer along with Mitsubishi spec'd a City Multi (VRF) PUMY outdoor unit with multiple indoor units. Unfortunately, this outdoor unit does not have hyper-heat, which means that in order to meet the 99% heating requirements, it will be grossly oversized for cooling. While the compressor can operate down to low-20% of rated capacity, that is still much higher than an MXZ minimum operation for the same sized unit.

Asked By Jonathan Lawrence CZ 4A New Jersey | May 21 18
1 Answer

Attic open-cell foam: off-gasing / odor

We have a traditional 1966 two story home, dual-zoned home in Atlanta (zone 3A). On April 18th we had our existing inadequate fiberglass insulation removed and open cell foam installed in our 1200 sq ft attic. We have had odor / off-gasing problems since. On cool, cloudy days it’s not very noticeable but on hot, sunny days the odor is quite pronounced and our second floor A/C (handler in the attic) is not usable as it blows in the odor/gases. We’ve been living with open windows and fans upstairs since. The odor is closer to the paint-like I have read about, not the fish-like.

Asked By User-7075353 | May 22 18
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