Q&A: A Forum for Green Building Experts and Beginners

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

The usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration:
Under the box labeled "More explanation," look for the words "File attachments."
Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


2 Answers

Why not skip the sheathing?

I am just a layperson who wants to build a pretty good home and have been considering two wall types, but as I'm reading, I feel like I’m missing something regarding the sheathing.

In General questions | Asked By Jonathan deHart | Mar 4 15
2 Answers

Remote cabin exterior wall design

Questions on remote cabin exterior wall design. I am building a small cabin, off grid in a remote location - Yukon Canada (cold dry climate). Not for full time habitation, but I suppose that could change in my future or with a with a different owner. Wood heat only, small solar to run LED lights, 12v stereo, no running water. Dimensions 16' x 24' (2 stories). I would like to minimize the exterior wall thickness as the interior space is not especially large to begin with. Cost and ease of construction are major planning considerations.

In Green building techniques | Asked By J. Bishop | Mar 4 15
5 Answers

Will adding rigid foam insulation to the inside and outside of my d-log house cause mold?

I am planning to add rigid foam insulation to the outside of my old leaky d-log house and adding douglas fir slab siding with chink. My electrician would like for us to fir out the inside to avoid having to router out chases for new wiring. If I add foam insulation (open or cloased cell) to the inside will I risk mold on the logs? The house is located in the upper Arkansas valley in central Colorado, zone 6 I believe.

In Energy efficiency and durability | Asked By Judith Blythe | Mar 3 15
1 Answer

Will a smart vapor retarder offer enough moisture protection to be used for bathroom walls?

We're planning to use MemBrain for an interior vapor retarder throughout our two story house currently under construction. The wall assembly is designed to dry to the interior. We want to limit moisture diffusion into the walls for the short duration of high humidity during showers while allowing walls to dry if sheathing accumulates moisture during heating season.

In Energy efficiency and durability | Asked By Dave Brooks | Mar 4 15
1 Answer

Connecting ICF Foundation Wall + Timber Frame / SIP?

I'm planning to build a timber frame home soon (eastern white pine and SIPs) and have received a decent quote for an ICF basement.

I like the idea of efficiency in this combination and know that others have built this way but am a bit confused about how they connect? We are responsible for the foundation and first floor decking before the timbers arrive.

Does any one have construction details they could share for this (ICF wall, sill plate, first floor deck, post, blocking, and SIP positioning)? If not can any of you share your experiences with this?

In GBA Pro help | Asked By Jeremy Mayhew | Mar 3 15
10 Answers

Dana, others, DIY PV, mini split, superinsulate, costs

What would it cost today to roof install 5.6KW of PV DIY?

DIYers are eligible for what rebates in NY in 2015?

Anyone?

Martin a blog on DIY PV and DIY mini split installation?

5,6KW PV for $2/W? $11,200?

DIY 2 ton mini split two heads, $1800x2= $3,600?

Superinsulate a 1,800sqft home, DIY cellulose purchase, 12" walls, 30" lid, $5.000?

These items can be done by one timers, DIYers.

Be nice to have a Q&A with this information on costs all in one thread.
Thanks
aj

In General questions | Asked By aj builder, Upstate NY Zone 6a | Mar 2 15
9 Answers

Seasonal humidity and lack of outside airflow

Hello,

In Mechanicals | Asked By Geoff York | Mar 2 15
4 Answers

Sealed crawl with passive exhaust?

I work with a non-profit building small, affordable houses in climate zone 4A. We have tried a few different methods of sealed/ conditioned crawls, but I am interested in finding the best, inexpensive method that will work long term for our buyers. So it needs to require minimal to zero maintenance or understanding of the science behind it for the people living in the house.

In Mechanicals | Asked By Emily Lingerfelt | Mar 3 15
5 Answers

Calculating break-even point when mini-split costs same as running boiler

I have original steam boiler that is maybe 75% efficient (it is converted to gas 10-year old boiler). Recently, because we wanted AC, we installed air-source heat pumps (Mitsubishi MXZ-2B20NA with MSZ-GE06NA and MSZ-GE09NA head units). Basically one heat pump has one 6K and one 9K heads.

I am located in Boston. COP of Mitsu I calculated at 2.6 since HSPF is 8.9.

So what I am struggling to figure out is at which outdoor temperature it makes sense to switch from boiler, that costs $1.5 per therm at current New England prices, to mini-splits at current $0.243 per KWh.

In GBA Pro help | Asked By Apollo S | Mar 2 15
12 Answers

Adding wall R-value in a historic retrofit

What options are available for adding r-value to a wall if we can't remove the exterior siding? I see three options...
1) dense pack cellulose in the existing 4" wall cavities (~R 14-16)
2) Closed cell spray foam in existing 4" cavity (~R 26-28)
3) Add a double interior wall filled with 7.5" of dense pack cellulose (~R 26-28)

In Green building techniques | Asked By alok khuntia | Feb 28 15
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!