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8 Answers

Order of upgrades

In an older house, is there a particular order in which air sealing and insulating upgrades should be made? I understand every situation is different, so I am looking for general guidelines. I am looking at possibly purchasing a 40 year old house and planned on trying to air seal the attic and rim joists of the crawlspace right away as well as duct sealing. Any big holes like pull-down attic stairs would also be addressed. After completing the most obvious work I'd like to have a blower door test done.

In Energy efficiency and durability | Asked By Daniel Gillen | Jan 28 15
1 Answer

Zone 2 wall insulation code

Was reviewing the IRC for insulation requirements for zone 2. Wood frame walls at 13 and mass walls with exterior foam at 4. Why the difference? And this brings up the real question which is: I'm about to put rigid foam on the exterior of a single story block house......any idea what the r value I should shoot for before reaching the point of diminishing returns?

In GBA Pro help | Asked By Robert Brown | Feb 5 15
3 Answers

Is rigid foam board over fiberglass batt insulation on a truss rim joist parallel to interior floor trusses ok?

My home in suburban Atlanta built in 2006 has a combination of 2 x 4 and TGI floor trusses built on a basement. On the rim joist parallel to the floor trusses it is framed with 2x4's 16" on center with a top and bottom 2x4 plate to equal the height of the floor trusses, 16 inches. The rim joist had poorly installed fiberglass batt insulation installed all the way around. I'd like to improve the insulation in these areas.

In Energy efficiency and durability | Asked By Brent Fischer | Feb 5 15
1 Answer

Need recommendations for WP and breathable house wrap/air barrier products that are applicable to residential renovation.

Has anyone had recent experience with the Grace Vycor enV-S, which seems to be what I'm looking for? Thanks.

In Green products and materials | Asked By Gary Glines | Feb 5 15
9 Answers

Ducted HRV, Lunos e2 or Extraction only

Thanks in advance for your knowledgeable advice. I understand just enough about air sealing, heat recovery, and ventilation to be completely confused as the best way to go about ventilating the house I am currently building. This house is a very small (700 sq ft./64 m2) open plan, one bedroom/one bath strawbale house with a small loft and a simple raked ceiling. I am attempting to build it very tight, but won't have actual figures on that until after the first coat of render and blower door test in April or so. I do need to consider electrical runs and potential ducting now.

In Mechanicals | Asked By Enga Lokey | Feb 1 15
1 Answer

Air filter MERV "sweet spot"?

I'm looking at air filters for my new house and was wondering if anyone had found a "sweet spot" in the tradeoff between filtration efficiency and cost, or some way to calculate that, or maybe a rule of thumb?

In Mechanicals | Asked By Roy Goodwin | Feb 4 15
4 Answers

Is it possible to simply drill and loose fill my ceiling to improve efficiency?

I have a 1950's split level in northern VA. My upstairs is 5-10 degrees colder than the rest of the house. Thermostats are on the main level set to comfortable levels but if I try to get the top level to the correct temp, anyone downstairs will melt.

In Energy efficiency and durability | Asked By Erik Cecere | Feb 4 15
3 Answers

Creating a conditioned crawlspace/air sealing questions

I have a 1940's ranch in climate zone 5a (Northern NJ) that's a bit of a disaster from an energy efficiency standpoint. One step that I'd like to take in the near-term is to create a conditioned crawlspace and I have a few questions about the best approach to take.

In Green building techniques | Asked By Eric Barker | Feb 2 15
2 Answers

Follow-up question on cut & cobble rigid foam in rafters

Several weeks ago many of you were kind enough to offer advice on a cut & cobble insulation project I undertook while converting our old garage into a new master bedroom. A quick update on my progress. After three long weekends and a few extra hours here and there, I have 8" of polyiso foam board fully installed (one layer between the rafters, one layer beneath). Both layers are ~95%+ airsealed (I now need to find an effective way of locating any last remaining leaks). The room is still unheated but the difference is palpable.

In Energy efficiency and durability | Asked By Brian Gray | Feb 4 15
4 Answers

How to insulate a cathedral ceiling under an exposed metal roof?


In GBA Pro help | Asked By Jennifer Duffy | Feb 2 15
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