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

Q & A Instructions

[Click map to enlarge]

The GBAGreenBuildingAdvisor.com web site has a wealth of articles on a wide variety of construction topics. Before posting your question, you may want to check out the articles on this page: How To Do Everything. You just might discover an article there that provides the information you seek.

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

If you want to post a question, 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!


4 Answers

Blanket insulation in basement

The builder installed a roll batt blanket insulation in an unfinished basement covering poured in place concrete walls. I am curious on opinion as to whether leave it and frame in front of it or remove it and frame off wall and insulate with closed cell spray foam.

Can the blanket insulation be left?

Thanks,
Tim

In General questions | Asked By Tim Miszuk | Jul 13 16
5 Answers

Slate roof and ventilation channel: Does the roof need ridge vents?

I have an old slate roof, want to insulate between the rafters in the conditioned attic and provide a ventilation channel of about 1.5 inches depth. My roof does not currently have any ridge vent or other ventilation outlets at the top of the roof. Does that mean that the ventilation chute is useless for venting away moist air?

In General questions | Asked By Matthias Paustian | Jul 12 16
11 Answers

Air sealing plumbing/skylight penetrations in insulated over-roof?

Looking at doing a chainsaw reno on a 1942 1-1/2-storey gable house. Region 4 Coastal.

Proposed stack-up (bottom-to-top) on the roof is:
- existing drywall
- existing 6-mil poly
- existing R-28 fibreglas batts over the inhabited part (poorly installed) with no ventilation chutes, no eaves vents
- existing 1x6 skip sheathing (from original cedar shake roof)
- existing OSB roof sheathing
- new BlueSkin VP160 vapour-permeable peel-and-stick
- new 8" of Roxul comfortboard IS, staggered
- new 2x4 strapping laid on side, aligned with rafters
- new plywood sheathing
- new tar paper

In Green building techniques | Asked By John Charlesworth | Jul 12 16
1 Answer

Quality cost-effective windows for new construction?

I am in the building stages of my full ICF house 2300 sq ft in Colorado (zone 5) and need to decide on what windows and doors I will be using. I would like to get quality, energy efficient windows and doors that will compliment the ICF walls. I understand the glass part of things fairly well as far as U-factor and SHGC goes, but my question pertains to window material and brand.

In General questions | Asked By Kyler Massey | Jul 13 16
6 Answers

Need help finding a contractor for energy efficiency projects

I recently purchased a home in Central Florida and have found the house need some extensive work in the attic. The ducts consist of a duct board trunk and flex pipe to the registers. The trunk line has deteriorated significantly and is leaking in many places. The flex pipe looks to have UV damage and the outer wrap is torn in a few places. I had a couple hvac contractors quote for fixing the duct work but they either suggested just patching or replacement consisting of the same poor quality materials that are up there already.

In General questions | Asked By Blake Lasslett | Jul 13 16
4 Answers

Crawl space insulation recommendation in Northern California

I plan to have the crawl space vented due to the additional cost to seal the crawl space. Home is at
Northern California - 5 months of heating season - wet cold weather, no snow, rarely go below freezing, low typically in 50s. Dry summer and I don't plan to have AC. There will be plumbing pipes and electrical wires in the crawlspace. Most new homes use fiberglass in the floor joist cavity in my area.

In Green building techniques | Asked By Amy (Homeowner) | Nov 25 10
15 Answers

Roofing and insulation on old house

I have an 1850s farmhouse I'm renovating. To insure good insulation, I had the attic rafters spray foamed with closed cell foam about four inches deep.

I'm trying to plan for an eventual re-roofing, and I wanted to know if there are any best practices I should keep in mind at that stage for eleminating any issues that might arise from the spray foaming. The old roof has a few layers of shingles on it.

Is there a recommended roofing type for this situation? Any ventilation issues I can helpfully prevent moving forward?

Thanks,

Ilmari

In Green building techniques | Asked By Ilmari Polojarvi | Apr 30 16
2 Answers

Siding/Rigid foam details

I am putting 2" of rigid foam on the exterior of my house with a rain-screen, then vinyl siding. What are the framing/flashing details for my electric meter box?

In Green building techniques | Asked By Ian Doherty | Jul 12 16
3 Answers

How do I calculate the payback period for additional insulation?

Location: Western NC, zone 4, mixed humid
Elevation 2000 ft
Roof: slope 2:12, standing seam.
Attic: formed with trusses and unvented
House roof insulation: Polyiso nailbase R15 min above the deck, netted BIBs below.

This follows on from a question I asked on June 30. We will insulate below the roof deck with BIBs. The cost of adding nailers, netting etc for the insulation is the same if we add the minimum thickness or if we add more. I can add another 1.75" for $500 to increase the R value from R23 to R30.

In Energy efficiency and durability | Asked By Jeremy Turner | Jul 12 16
1 Answer

Permission to reproduce Holladay article in Australian publication

Hi Martin, we would love to reproduce your article about the 30 year old PV system in our magazine Solar &Storage which is circulated to the industry across Australia.
This pioneering effort makes for a great read
Our thanks in anticipation
Nicola Card
Editor
Solar&Storage
for
Australian Solar Council

In General questions | Asked By Nicola Card | Jul 12 16
Register for a free account and join the conversation


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