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17 Answers

solar quotes & info feedback

concerned with proper sizing and associated costs of course...

we’ll be building a "pretty good" 100% electric house in the the white mountains of NH, USA and this is a huge question that we need to answer. of course i have the requisite fear of undersizing…

some rough details:

1350 SF conditioned space
will be using mini splits for heating
heat pump water heater
possibly condensing/heat pump dryer
wife may go all electric car in future

quotes from one company all prices USD:

option 1:

In Energy efficiency and durability | Asked By John Williams | Mar 27 18
16 Answers

Wood Stove with HRV

We live in an 1942 brick colonial (about 1,000 sq ft each level) in Minnesota. We have both a wood stove and a forced air furnace. We burn about 3 cords a year which covers most of our heating needs and the furnace fills in the gaps. We also rely on the furnace fan to circulate the warm air from the stove throughout the house. Not perfect, but it keeps things pretty evenly warm. Last year, we had a blower door test done and were told our house was too tight after new windows, doors and adding closed cell spray foam to the attic and rim joists.

In Mechanicals | Asked By BC-L | Apr 6 18
8 Answers

Main Floor Cantilever

Hello. I am working on a project where the main floor is cantilevered over the concrete foundation wall. I am having a hard time finding details showing the sealnt, barriers, and insulation for the cantilevered floor. The details I do have show a cantilever over a wood frame wall, not a concrete foundation wall.

any suggestions would be greatly appreciated. Thank you.

In Green building techniques | Asked By user-7049485 | Apr 9 18
8 Answers

Mystery mold around a hot roof...

Hi Everyone!
I have a real head scratcher (for me) that I'm trying to problem solve. Bear with me, there's a fair amount going on here:

In Energy efficiency and durability | Asked By David Bailey | Apr 9 18
8 Answers

exterior door threshold slopes towards door

I've recently discovered that the threshold on the door leading to my "flat" roof balcony is not only not properly sloped, if anything it actually slopes toward the door. The door threshold is really deep, about 18", so this makes the problem even worse. I've been trying to figure out what to do about it, and at a loss. Do I have any options besides removing the door, tearing up the deck membrane and doing it all over again? The builder is long gone and of no help.

In General questions | Asked By Trevor Lambert | Apr 9 18
5 Answers

Spray Foam On Brick Wall... Close or Open Cell?

Per the excellent advice and columns on GBA I have decided to go with close cell under the roofing deck and gable ends of an old house project in climate zone 5.

If I may ask one more question concerning the brick interior step wall (see link).


Should I use open or close cell spray or maybe even something like cellouse?

I plan to furr out the wall with either 2x4 or 2x6s. I have read close cell on brick interior can cause problems with brick to be wetter in the winter and result in long term duribility problems.

In Energy efficiency and durability | Asked By truckaxle | Apr 8 18
8 Answers

AdvanTech as Air barrier

Just wondering if AdvanTech sheathing could be used as an air barrier if taped?

Just wondering because of the past failures of OSB as an air barrier.


Also if so, what tape, I was planning on using 3M All Weather Flashing Tape but not sure if anyone had experience using it on this product?


In Green building techniques | Asked By Dave B | Apr 6 18
4 Answers

ERV/HRV, central system vs select multiple units

I did my best to "build it tight", sealed/caulked/taped framing, XPS outsulation caulked and taped at seams, multiple WRBs (below and above the outsulation, etc...
Now the "ventilate it right" issue is my next challenge. Looking for good advice. opinions, input.

In Energy efficiency and durability | Asked By Sal Lombardo | Apr 9 18
6 Answers

Mono Pitch Porch

I hope I use the correct terminology, building a porch, which has a mononpitch, almost like a canopy or an awning. Searching for illustrations or technical data on how to flash the corner, where the side wall meets the porch roof.
Metal flashing will be tucked under the housewrap, but should the metal flashing extend over the porch by a few inches? How do you detail this corner section?

In General questions | Asked By Birdie L | Apr 9 18
10 Answers

How important are air barriers in a vented cathedral ceiling?

In August we had R60 of closed and open cell Demilec foam sprayed in our 1700 sq foot roof that unfortunately had a bad off gassing problem. After chemical (air and foam) testing and a long negotiation they agreed to remove the toxic foam. Removal was a long messy process but its finally done. Now we are looking to insulate with a non foam product which means converting a hot roof design to a vented assembly. We have 14" TJIs to work with and the roof deck covered with vapor closed underlayment and vented metal roofing so at this time nothing can be added above the roof deck.

In Energy efficiency and durability | Asked By Ryan Williamson | Apr 6 18
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