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4 Answers

Basement / crawlspace insulation

Basement of an addition has two levels. Most of the space is at normal height but about a third is raised to only about three feet high. Needed to do this because of the nearby ISDS. Energy auditors are recommending rigid foam on these "crawlspace walls" and not all the walls. Does this make sense?


Asked By Jonathan Blaney | Jan 16 18
3 Answers

Sheathing wetting / drying cycle

Climate zone 4:
Mean outdoor T/RH for cold months (Dec/Jan/Feb) are: 36/78, 37/82 & 41/70

Proposed wall is:
Anchored brick (3.5") veneer, 1" air space, Tyvek, 7/16 OSB, 2x6 wall with cellulose, 1/2 gypsum, latex paint. I don't have a lot of options here, but for reference the "standard" is 2/4 with batt.

Nothing complex about the wall but I have some questions.

Asked By Stephen Cook | Jan 16 18
4 Answers

Acceptable moisture content levels in wood tongue-and-groove boards?

To all,

Searching this site and the web. Surprisingly, I could find very little on what is an acceptable level of moisture in wood V groove T&G 1x6" paneling. FYI the wood species is Red Pine (Norway Pine)

The ceiling areas the wood will be placed has a 1 1/2" space behind it and the air barrier.

I have found some wood at 1/3 the price of kiln dried, and in the lengths I need. However, the wood was air dried, and currently is showing 10-12% moisture content. I think kiln dried is about half that.

Asked By Steve Lenertz | Jan 15 18
2 Answers

What do you think of the flex duct on this job?

We added some HVAC ducts to our basement's existing metal ducts as we plan to finish it. I have three questions about the Flex Duct they put in.
1.) Is flex duct ok to use in a basement like this?
2.) Is the way they installed the marked "A" okay? Looks a little sloppy to us how they tried to twist it into a bay, but what do you think?
3.) Are these both insulated? And, if not, should they be and is that something they can easily add?
Thanks in advance!

Asked By Masb | Jan 16 18
11 Answers

Vinyl windows with synthetic stone

Hoping this isn’t a bad question.....any advice for detailing Synthetic Stone around vinyl windows (some have integrated J channel, some have brick mounding with integrated J channel).

Asked By Birdie L | Jan 7 18
11 Answers

Cycling of heat pump

I have a Fujitsu heat pump with two indoor units each in relatively small rooms. (For good or bad, this decision was made because I was not satisfied if only one room had a unit that sufficient heat could be transmitted to the second room and I wanted each room to have its own thermostat. I recognize that they are larger than I need but I did not see good alternatives) Currently both units are set on "minimum heat" (50 degrees F) because the rooms are not occupied for days at a time.

Asked By David Martin | Jan 14 18
4 Answers

How to insulate an enclosed garage ceiling?

In my work as a building analyst here in Southeast PA, I meet lots of homeowners having comfort issues in conditioned spaces above garages. Typically these spaces are cold in the winter, though not necessarily warm in the summer. Quite often, there is fiberglass batt in the ceiling cavity of the garage (covered by drywall). In many cases, the batt has kraft paper and is facing down towards the unconditioned garage, sometimes up against the floor and sometimes lying on top of the ceiling.

Asked By GreenerLiving | Jan 15 18
5 Answers

Another try at a ceiling service cavity framing

I now want the duct ed mini split IDU(s) and ducts within the ceiling therefore what I thought was an economical construction (lattice of flat wise 2x4s) really is not, especially if I'm to have code acceptable ducts. I simply need a taller cavity, 3" isn't enough, 6" is probably minimum. My latest thought is to use a variation of a Larsen truss (2x2 chords and OSB strips on alternating sides forming the "web") installed horizontally. The "Larsen's" top chord is fastened through the upper air barrier material (probably drywall) with screws into the bottom chords of the roof trusses.

Asked By Jerry Liebler | Jan 15 18
8 Answers

Cold Wet Sheathing, Double-Studs WITH Vapor Barrier, or Not?

John's recent post about open cell foam in a double stud wall here:


...got me wondering about a VERY basic question. The articles linked to by Dana Dorsett refer to this BSC study where double stud wall moisture was evaluated with three different insulation strategies: 12" cellulose, 12" Open Cell spray foam, and 5.5" of Open Cell spray foam.

Asked By Lance Peters | Jan 12 18
3 Answers

Best way to install rigid foam insulation below floor joists from crawl space?

I have had to remove fiberglass batting from my crawl space due to the intrusion of rodents. This has left the underside of our floors uninsulated. I am thinking of replacing with 4" polyIso foam board. However, I am not sure what is the best way to install it:

Should I "cut and cobble" between the floor joists? This will be time consuming and will lend itself to thermal bridging. Or should I secure to the bottom of the floor joists? Doing the latter will leave a 6" gap between the rigid foam insulation and the sub floor. Is that too much?

Asked By Mike from Lafayette | Jan 15 18
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