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!


13 Answers

Engineered Hardwoods?

Hello. We are building a new house and are looking for a flooring other than carpet, tile, or linoleum to put throughout our entire ranch and finished walkout basement. I was considering a green guard certified laminate, but heard that floating laminate does not do well on stairs (we have stairs to basement). I do not want any carpet or a runner due to allergy issues and want the same flooring on the stairs as the basement and main level. Does engineered hardwood do well on stairs? Normal hardwoods are out due to needing to be in a basement.

In Green products and materials | Asked By Kara English | Jun 20 16
20 Answers

PEX A vs. PEX B

I am obsessing over which pex to use for a whole house manifold installation. The choices are pex-a (uponor) vs pex b (viega).

Uponor seems easier to work with, less kinking, better flow etc.

What I am most concerned with is:

1.longevity (this is my forever house)
2. safety (leaching of chemicals into drinking water)

I am on a well.

Any input as to the longevity and safety of these two different types of pipes?

Dean

In General questions | Asked By Dean Sandbo | May 26 16
9 Answers

Attic insulation question

I have read many of the posts and articles about different ways to bring an unconditioned attic into the thermal envelope of one's home and I'm currently weighing some options. I will likely use spray foam under the rafters of my attic (9.5 inches). I've read the various debates about using less spray foam than would be required to achieve the desired R-value (eg R of 49 in my zone 4a area), with the argument (from the spray foam manufacturers it seems) being that spray foam yields a more effective R-value so you don't need as much as you would think based solely on R-value calculations.

In GBA Pro help | Asked By Rob Moore | Jun 17 16
4 Answers

Re-siding / re-sheathing a 30-year-old double-stud house

I'm in Zone 6. My mother's house was built from the late 70s to the early 80s (not a guess -- it took that long).

Walls are 2x6 and 2x4 staggered studs with pink glass, poly, and sheetrock on the inside, rough-sawn board sheathing, rough-sawn board-and-batten siding. Andersen 2-pane casement low-e windows.

It's time to replace a bunch of siding, as the bottom is rotting where it is close to the deck (rain splashing up in the summer, and constant snow contact in the winter, my guess).

In Energy efficiency and durability | Asked By Trevor Chadwick | Jun 19 16
29 Answers

Most inexpensive way to build a small guest house?

Would a SIP, ICF or stick frame be the quickest and most inexpensive way to built a small < 1,500 square foot guest house?

This would be in a Zone 4 climate. The most important factors are build-time quickness, strength and simplicity.

In Green building techniques | Asked By Peter L | Jun 2 16
3 Answers

Solutions for rain screen strapping "sucking in" rigid foam?

During installation of 1X4 strapping (fir) over rigid foam (EPS) with Headlok screws, my builder has been remarking about the Headlok screws tendency to "suck in" and compress the foam.

Anybody have creative solutions for this?

In Green building techniques | Asked By Thomas R | Jun 12 16
9 Answers

Unvented low-slope roof: Do I need a vapor barrier or an air barrier?

I am looking to increase the installation in a bedroom in an early Mid-Century modern home (built 1949).

We are in Zone 3. Roof is low slope 1:12

The house was re-roofed approximately three years ago with a IB Roofing Systems 80 mil PVC membrane in Dark Brown.

I have attached a rough diagram of the roofing layers in this area of the house

In General questions | Asked By Dan Dutcher | Jun 18 16
10 Answers

How can I stop the mold recurring in my wall?

I have a bonus room over my garage with a double window at the gable end. The outside of the wall is brick faced, wrapped in Tyvek over OSB. The inside has fiberglass insulation, and drywall. The house is 12 years old, located in the Midwest.

In GBA Pro help | Asked By Carr Bruton | Jun 18 16
9 Answers

Slab insulation - do I understand the code requirements?

Question about slab insulation. The current slab has zero insulation on each side. That was no issue until now because it always an unheated garage. The slab is just that, a slab. No footing, no drainage.

Living in zone 5A and using the table Martin gave me in another thread I conclude I need:
- R-10 on the edge. --> 2.38" EPS or XPS*
- R-30 on top of the floor indoor. --> 7.14" EPS or XPS*

*= I use R4.2 for both EPS and XPS because I will use reclaimed foam. From what's I've understood XPS outgasses and it's R-value drops to that of EPS over time.

In Building Code Questions | Asked By Tony Tibbar | Jun 18 16
7 Answers

HVAC system sizing

Good day everyone. I'm in the process of building a new custom home in northern NJ. I'm trying to be as energy efficient as possible within budget. It's approximately 5000 Sqft under air, 2.5-story home with a finished basement (included in total sqft calc). I'm trying to properly estimate my HVAC system. The house has R19 insulation on the walls, and R30 in the attic. It has poured concrete foundation. There are 35 (Pella proline) windows in the house, all double-pane, along with 2 glass sliding doors. Exterior walls are 2x6 construction. Front door is R16 rated.

In Energy efficiency and durability | Asked By Eugene Shebayev | Jun 16 16
Register for a free account and join the conversation


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