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9 Answers

What's the best way to renovate/rebuild an old south-facing exterior wall?

Hi All - I am a newbie to this group but have considerable building experience remodeling and renovating homes, and completing unfinished properties. Still, I am no expert building contractor.

In Energy efficiency and durability | Asked By Roger Smith | Oct 2 16
2 Answers

2016 heat-pump water heater rebates - Opinions on best heaters?


There is a $750 Massachusetts rebate on air source water heaters. There are a lot too choose from. Any opinion on which one would be the best choice for a small 2 bathroom?

Thanks for any input.


In Green products and materials | Asked By Seth Capista | Oct 18 16
2 Answers

Attic insulation

I'm curious if anyone has any advice with concern to insulating an attic that contains a gas furnace (sealed combustion)? The unit is placed pretty close to the rafters- about 8"- and the attic is only about 5' at the ridge. Is it best to create a conditioned space for the unit or the whole attic? I'm new to all of this, so I'm not sure what to watch out for. Any advice would be appreciated. Also, does anyone have any recommendations for insulation contractors in the Boston area?

In General questions | Asked By Jeff Cannon | Oct 15 16
13 Answers

High Performance Home definition in as few words as possible.

I would like to see something less than an elevator pitch that gets to the route of what a high performance home is for the average potential new home client. Everything is too wordy and goes into air sealing, superinsulation and the why and the how - too much eyes-glazing-over detail. We need more of a slogan in this business. I'm putting it out there as a problem to work on. 140 characters perhaps?

In General questions | Asked By Robert Swinburne | Oct 17 16
3 Answers

New HVAC not blowing cold enough... what are the common causes?

I have just had a second new HVAC unit installed. A Trane xr17 condenser and s9v2 furnace. it is installed in my conditioned crawlspace, and I have an identical setup in my foam encapsulated attic.

In Mechanicals | Asked By John Sexton | Oct 18 16
7 Answers

Mitsubishi minisplit reconfiguration


In Mechanicals | Asked By Ben Thrush | Oct 17 16
1 Answer

Can 1.5" and 2.0" unfaced XPS be used as a continuous rafter baffle?

I am considering using either 2.0 or 1.5 XPS as a continuous rafter baffle (from soffit to ridge vent) using a 2" vent between the XPS and the the roof deck. The rafters are nominal 2x10s and the underside of the rafter will be insulated with Roxul and then covered with finished plywood with a high quality latex paint (Class II or preferably Class III vapour retarder). I have only seen 1" XPS recommended by GBA. Can a thicker board be used or is there concern re: drying to the exterior given the relative impermeance of the thicker board?

In GBA Pro help | Asked By Andreas Seibert | Oct 18 16
1 Answer

Replacing siding on an old Toronto house


I need to replace the siding on my house. I've read through this article, but still have some questions:

Some info:

In General questions | Asked By Jon Haque | Oct 18 16
11 Answers

Insulating an addition built on piers and insulating corners

I am starting a 16' x 21' addition that will be supported on 8' tall block/brick piers. The floor will be framed with 11 7/8" I Joists. I contacted an insulation sub for the insulation work. Here are the details:
23/32" plywood sub floor
11 7/8" I joists
Sub will apply R30 of Icyene open cell foam to bottom of sub floor (leaving approx 3-4" air gap to bottom of joists
I will install 2" XPS foam, then 15/32" ply, Tyvek taped for air sealing, and vinyl soffit,

In Energy efficiency and durability | Asked By Dave Otto | Oct 13 16
14 Answers

Add rigid insulation to a 2x4 ceiling with an existing polyethylene vapor barrier?

I've been creeping around this website for years. I love reading random articles and questions and learning this stuff for fun.

Zone 6. We live in Southern Maine (Scarborough to be exact, stop by and say hi!).
Our "play room" appears to have been built (or renovated) as part of the garage addition, date unknown. Our house is 1960ish.

- (Section A) About 300 sq.ft. of the room is a flat drywalled ceiling, 8' tall. 2x6 framed ceiling. "Attic" space

In Green building techniques | Asked By Seth Fernald | Oct 3 16
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