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3 Answers

Will fiberglass insulation retain interior heat that a thermal barrier (foil) will not?

I have an unheated shed for gardening tools, equipment, and chemicals that has foil backed plywood walls and roof sheeting. I plan to install standard plywood to the interior walls. Summer temps average 90 to 100 degrees max so the thermal barrier of the foil should provide some insulating value to keep the interior somewhat cooler. I am concerned that winter temps that typically dip to the 20s but occasionally could dip lower, could cause something in the shed to freeze.

Asked By user-7026765 | Feb 23 18
5 Answers

Closed-cell or open-cell foam?

With a wall system that consists of 2"x4" wood framed walls, 1/2" plywood sheathing covered with #15 building paper or house wrap and sided with vinyl or cement board would closed or open cell spray foam provide some level of water resistance during a minor flood? Would the sheathing and studs be able to dry? Would rock wool be a better choice for insulation?

Asked By Anthony Swoope | Feb 23 18
3 Answers

HPWH - To duct or not to duct?, that is the question

As noted in an earlier question, I will be putting a heat pump water heater in my crawlspace. The Rheem unit I have allows ducts. I want to get the maximum circulation of air in my crawlspace to dehumidify it and am wondering if ducting the cooled exhaust to the far end of the crawlspace might be worth it. Rheem says I can use up to 125' of 8" flex duct, which should be more than enough.

Asked By Norman Bunn | Feb 23 18
4 Answers

Which would you recommend for exterior insulation in climate 5 Habitat for Humanity home?

I specifically mention Habitat for Humanity, as this means, the work is executed by volunteers and quality control may be an issue. Will the taping and flashing be done exactly right..? Which solution would offer a most "fool-proof" option? I specifically worry about reverse flashing created by somewhat incorrectly installed horizontal tapes. Read couple of articles on that...

Asked By Lucyna de Barbaro | Feb 23 18
1 Answer

Sealed crawlspace next to walkout basement with HPWH

Greenville, SC
CZ 3A (mixed humid)

Extensive rock has limited the amount of basement I can put in, so I will have a rather tall crawlspace adjoining my walkout basement on two sides. The basement will have interior foam insulation (R-10) on the poured concrete walls, R-20 on the walkout side, and will be unfinished for now. The crawlspace will be sealed and also insulated to R-10.

Asked By Norman Bunn | Feb 23 18
12 Answers

How exterior air seal at chimney to wall interface? Chimney spalling.


Using a FLIR One, I've found a major source of air leakage into my house from around the fireplace mantel. Using a homemade blower door and a smoke pen I've discovered that the air is in fact entering from the exterior chimney to sheathing interface. While I've been able to find extensive discussion and documentation on this site how to handle through attic air gaps for a chimney, it's been less clear to me how to handle this detail on the exterior wall to chimney brick intersection.

Asked By Mike McLaine | Feb 18 18
5 Answers

Slab on Grade in Climate Zone 6

Hey all,

So watching a bunch of Matt Risinger, he's always talking about slab on grade builds, and how we have basements in the far north etc. I know these topics have been brought up before.

I'm in Climate zone 6, Toronto. I'm designing a 100sqft satellite building, or you could call it a shed with all the bells and whistles of plumbing, elec, heating etc.

I'd like to do a frost protected slab on grade for this to incorporate infloor radiant hydronic heating. The slab will essentially act as the radiator, and be the base for the Insulated perimeter wood stud walls.

Asked By Jamie B | Feb 17 18
5 Answers

Should I run my water heater in air source heat pump mode during the heating season?

My husband and I live in Minnesota (Zone 4) and have a small SIP house heated primarily with a Fujitsu Mini Split. Our water heater is a GE Geospring air source heat pump water heater.

I was wondering whether it is most efficient to run the hot water during the Winter months as a straight electric resistance heater, or to continue to running it in heat pump mode.

Asked By Mikaturner | Feb 20 18
25 Answers

Insulation upgrades

Hi Everyone.

Thank you in advance for your feedback, you have all been so helpful.

Zone 5A (coastal Mass) house.

I have an older 3200 sq ft home with a mix of well-pointed fieldstone foundation and poured concrete. The 1000 sq ft attic is currently air-sealed in most places, and has a mix of fiberglass batts and cellulose for about R-30. I have 10 recessed lights in attic, which have the LED airtight retrofits with gaskets, but are not covered in cellulose. The recessed fixtures are IC-rated. The remainder of the home has vented cathedral ceilings (sigh).

Asked By Justin Brown | Jan 22 18
9 Answers

Maximizing thermal mass in passive solar high desert home

Hello -

My partner and I are building a small (600 sq ft) house in climate zone 5B (NM/CO border). When we lived in Colorado, we had friends who built commercial passive solar greenhouses using south-facing glazing and water tanks for thermal mass. Using their formula, we calculated that we would need approximately 1500 gallons of water to meet their design specs for a self regulating high desert (7k ft elevation) house of this size.

Asked By Zane Bridgers | Feb 19 18
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