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0 Answers

I am considering a double wall construction

I am planning to build a house in Charleston, SC (Hot -Humid Climate) and would like to get as close to Net Zero as possible. I think mini-splits will work but dont know if double wall construction is the way to go. Any help would be appreciated.

Asked By Rick Fetter | Oct 30 14
3 Answers

A very low addition...

We've been contracted by a repeat client to build a small dining room addition (11' x 12') attached to a contemporary ranch in Maine. Due to very difficult access issues, the addition has to be supported on sonotubes. Bottom of joists (2x10 with fg batts) will only be 2-3 inches over grade.

Asked By ron letourneau | Oct 29 14
13 Answers

Closed crawlspace with dehumidifier and foundation insulation

I am still in the planning stages of building my new house. I would like a closed crawlspace (I'm in a mixed humid climate) with a dehumidifier and foundation wall insulation. See page 35 (which is actually page 41 on the pdf page counter) for a sample design of what I'm going with. I have two main questions about this design choice:

Asked By Michael Geoghegan | Oct 27 14
102 Answers

Water - The Wonder and the Danger

We live on a watery planet. 70% of the earth's surface is water (the same percentage of water in our bodies). It is the font and sustainer of life (SETI looks for water on other planets as the sine qua non of life). So why have our modern "green" building practices turned it into a monster? And how can we stop fighting it and turn it back into an ally?

Asked By Robert Riversong | Nov 28 10
6 Answers

100-year-old single-pane windows, storm windows with low-e, or interior panels?

1. Is Low-E a good choice for all windows, or should it be selected for certain windows according to their location?

2. Is there any unbiased performance data available for storm windows? In particular Larson windows? I have found an interior panel (link below) that claims a U-value of .29 and has achieved Energy Star recognition. Can a Single pane, low-e storm window do a better job? I think it's worth noting that a single pane storm being mounted on the outside of a 100 year old window frame may reduce drafts entering the window frame area more than an interior panel.

Asked By b l | Oct 29 14
4 Answers

Climate Zone 6: Low-slope warm roof materials / assembly

I am designing a large mono-pitch shed roof in Climate Z6. The slope is 1.5 in 12 or about 7 degrees. A ventilation space seems impossible due to the scale of this roof plane. 60 feet sloping up and about 25 feet wide. I would like the finished roofing to be standing seam metal as the roof is visible from various vantage points on the property.

It my understanding that we will need to install a high-temp waterproof membrane like Grace Ultra over the entire roof sheathing to prevents leaks. This means the roof assembly is only able to dry to the inside.

Asked By Meri Tepper | Oct 29 14
1 Answer


I recently purchased a 1930's brick and aluminum-sided two-family home in Teaneck, NJ. The insulation in the upstairs apartment is very old and dilapidated and lining the roof. The outside walls in both apartments are not insulated, it would seem. I would like some ideas about insulation. Can call me, too, 646-245-3801.



Asked By Janice Thill | Oct 29 14
11 Answers

Can I use R-15 rock wool batts in a REMOTE wall with R-20 exterior foam?

I have read many articles on this site (thank you) and am currently using some of what I have learned in my house construction in Ridgway CO. For reasons I need not go into, the house has two wall systems – the north and west walls are built from ICFs. The south and east walls will be 2x4 studs, plywood sheathing, Tyvek and two layers of taped exterior foam with an R value of 20.

Asked By Gary Dick | Oct 28 14
4 Answers

Insulating a metal barn

I have read a lot about condensation problems when insulating metal barns, as well as your blogs on bubble wrap scams and subsequent commentary.

Asked By brian mccoy | Oct 27 14
7 Answers

Add R-14 Roxul between the garage attic and the house?

I am currently in the process of insulating my attached garage using Roxul R14 "ComfortBatts". I live in Winnipeg and from experience -- when I did this in my last house -- it can improve the temperature by 10-15 degrees Celsius in the winter, without any heating. (And that was with a non-insulated garage door; my new house has insulated garage doors!)

Asked By Mike Lucas | Oct 23 14
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