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6 Answers

Air sealing attic: materials and fire safety

I'm a homeowner thinking to do some DIY air-sealing in the attic. I was preparing to use caulk on narrow gaps (top plates), and spray foam on larger gaps (penetrations for cables, plumbing vent stack, etc). Not being a pro, I was going to just stay away from anything thermally hot, like the furnace vent.

Asked By Sam Smith | Oct 25 16
17 Answers

Sun Bandit solar water heater

Hello. I was reading the article by Martin Holladay entitled "Solar Thermal is Really, Really Dead" and enjoyed the discussions going back and forth on the topic of solar water heating methods. I am planning on building a small 600sq' SIP cabin in the area of Nelson BC (climate zone 6) next year and I found this product listed as being one of the most efficient for heating domestic hot water on the Canada Energy Guide site. It says it can also be used for space heating via a radiant floor system or perhaps radiators.


Asked By Scott Wilson | Oct 21 16
76 Answers

While I love radiators, I hate using fossil fuels

I live in an 1890 Victorian in Southern Pennsylvania, heated by oil. While I love radiators, I hate using fossil fuels! Is there a way to use green technology to use less oil? My methods to date have been uncomfortable - installing a wood stove.

Is there a way of boosting the boiler with green energy? Would geothermal help? I'm newly divorced and ignorant about systems!
Thanks, Susan

Asked By Susan Hanway | Aug 28 16
3 Answers

What causes a bathroom vent fan to drip water?

A customer has a bathrrom exhaust fan which drips water. The pipe originally went up then turned horizontal and exited the bldg. I now goes straight up. He covered the aluminum duct- short run- maybe 18" with spray foam to insulate. Do we need more insulation?

Asked By Steve Mindel | Oct 26 16
2 Answers

We're preparing to begin an extensive green remodel of our home

We would like assistance in locating a contractor in our area (South Florida). Please share any contacts you may have.

As a new "student" of Green Building/Remodeling, I'm invested in the success of this project for professional experience that I can use in the future.

Asked By Chanda Levy | Oct 25 16
4 Answers

Foam sheathing insulation on basement block walls

Building a new home in Syracuse NY. We will have two bedrooms in the finished basement (not walk out but large egress windows). I want to use foam sheathing on the concrete block walls - primarily as a vapor retarder but also for it's insulating value. I have read differeing opinions on the ideal permeability rating for foam in this situation. BSC says to keep it permeable but I have read elsewhere (here maybe) to use impermeabile. I have my eye on 1" XPS because Lowes has it in stock.

What do people recommend? Thanks

Asked By david schreiber | Oct 23 16
1 Answer

Covering and insulating the exterior floor of a raised pier/beam home

Hi, our family owns a home on the South Carolina coast which was built on 18 foot piers. At some point in time, the prior owner sealed the exterior first floor (ie, the "underneath" of the home) with drywall. Although the drywall was painted for protection, a few portions of the drywall appear to be damaged from moisture and in some spots have mildew.

Asked By Brian Jackson | Oct 26 16
2 Answers

Low profile cans /speakers below closed cell in a flash and batt roof.

I have a retrofit (zone 4, Humid SE) where we're doing an unvented roof with 4" closed cell SPF and an R-13 unfaced batt.

Contractor and client have been asking to use low profile speakers and can lights below the SPF layer. Generally I have been hesitant to do that as I'm unsure to what extent those penetrations in the G.W.B. will pose issues thermally and hygroscopically But if the foam is very solidly our air/moisture barrier, do I need to worry about those penetrations?

Asked By Chris B | Oct 26 16
9 Answers

More rim joist insulating questions


I know this topic has been discussed a lot, but I cannot find exactly what I am looking for.

We have a 1926 Tudor in Minneapolis, MN. I am in the process of finishing our basement and I plan to use 2" of rigid foam on the walls and potentially between the joists to seal up the rim joist. I may use closed cell spray foam to seal the rim as well. My problem are:

1. We have concrete poured between our joist onto the foundation making it difficult to use rigid foam. The concrete is also poured very uneven. This is why I may use spray foam.

Asked By Joe Sweeney | Oct 25 16
1 Answer

Insulate rim joists with closed cell, with rigid foam on exterior?

I have a new construction home, zone 5. I wondered if you insulate the rims joists with closed cell foam, when we have 3" of rigid foam on the exterior?

Asked By Michael Brackett | Oct 26 16
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