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22 Answers

Insulating plumbing vents and drains?

Is it worth the expense and time to insulate drains and vents? Essentially they are outdoor spaces inside your envelope? Just trying to decide before closing up some walls.

In Green building techniques | Asked By Lance C | Sep 10 15
9 Answers

How to use water for thermal mass

I have a room in the basement that has a large south-facing window. We don't really use this room but it would be nice to use the solar heat that collects in there to warm the basement. What is the cheapest way to use water as thermal mass? If tubes are the answer, what kind of tubes? If a barrel, what color? Can I use black plastic 55-gallon drums? Thanks for you help!

In Green building techniques | Asked By Beth Sorrell | Dec 13 10
8 Answers

Slab against rim joist detail please

New construction: back patio will be a slab poured against the rim joist so it is nearly level with the door threshold. Rim joist will be 11 7/8" atop a retaining wall back-filled with gravel, so there will be good drainage. The patio will be covered with a roof, and slope away from the door of course.

What's the best way to permanently protect the rim against water, moisture, and termites?


In GBA Pro help | Asked By David McNeely | Oct 8 15
6 Answers

Insulation type, etc.

hi all,

i have a semi-detached brick 2-family home in brooklyn. 20' x 65'. tenants are on the top floor and we occupy the first 2 floors. our ground floor is about 3 feet in ground on 3 sides and at grade in the rear. we are renovating and intend to put 2 full bathrooms and 3 bedrooms there, in addition to the laundry and utility room. we recently install a navian ncb240 which currently serves our dhw and baseboard radiators for both floors (tenants have separate boiler).

In Energy efficiency and durability | Asked By Josh Millis | Oct 1 15
3 Answers

Sure, exterior rigid foam when blowing wall cavities might be a good idea, but is it NECESSARY?

My 1920 platform framed home is on the border of climate zone 5&6.

The empty wall cavities are framed with true 2x4s, 16 OC. Walls are covered with lathe and horsehair plaster on the inside and 1" pine sheathing boards outside. The current siding is a horrendous installation of vinyl over the original clapboards. The cavities are now empty.

We intend to remove the vinyl (carefully, for reuse), strip the clap boards, dense pack the wall cavities, wrap the house in tar paper, and rehang the vinyl.

In Energy efficiency and durability | Asked By Mark | Oct 5 15
7 Answers

Limited soffit venting clearance for baffles + insulation

Just installed a new roof with Maximum Ventilation exhausts and removed old fiberglass batts. I was originally planning to do the standard R50 fiberglass blow-in and soffit baffles. However, I discovered that in this 1960's back-split, the roof is quite shallow and rests directly on the double brick wall so there is only 3-4" clearance for soffit venting, leaving only 1-2" left for insulation under the baffles around the perimeter. This seems like a recipe for cold spots.

Some options:
1. Just proceed as planned; hopefully cold spots won't cause condensation on the ceiling.

In General questions | Asked By Deb N | Oct 8 15
11 Answers

NON-Flanged (Insert) Window Replacement + Flashing

I changed out my rotten wood framed windows for all vinyl ones. The original wall was aluminum siding. I fixed the rotten sheathing, applied house wrap. Then strapped (furred) the wall with plywood. The pictures show how I flashed the rough window openings. I did NOT want flanged windows because I did not want to have to disturb the siding when the window needs to be replaced in the future (far into the futuer I hope). I see a lot of articles on how to flash flanged windows, but I never see methods for Insert (non-flanged) ones.

In Green building techniques | Asked By Alexander Sanita | Sep 28 15
6 Answers

Vapor barrier in attic?


In Energy efficiency and durability | Asked By Lucy | Oct 4 15
1 Answer

EPA-approved wood stove with sealed-combustion design?

I'm working on a retrofit that mandates that any wood stove must be EPA approved as well as have dedicated combustion air. I have had trouble sourcing a wood stove with a dedicated combustion air inlet . Is anyone aware of a product with this feature?

In Green products and materials | Asked By John Kidda | Oct 8 15
14 Answers

HVAC selection help

My new house is under construction and I need to finalize my HVAC system soon. Some details:

Zone 4, 3800 sq feet (About 1900 first floor, 1550 second floor, 350 room over the garage), crawl space (conditioned), open web floor trusses for second floor.

I had the manual J load calc reviewed by an engineer and have sent it back for some corrections (there is better insulation than is shown and better air sealing, and a couple other things which will lower the load. He didn't add the ventilation load though, which will raise it), but as it stands right now:

In Mechanicals | Asked By Michael Geoghegan | Oct 7 15
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