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6 Answers


My hubby and I are in Western PA (5A) and are in the works of building our home w a local builder. Their standard material is Blue Dow board or SIS. I found it a little curious at first using Styrofoam to hold a house up but hey what do I know about houses. From the inside out it goes: drywal, insulation, 2x4s with some metal reinforcement, then the SIS,some plastic wrap (for lack of better term) then the siding. This gives it a R-19 rating. I inquired later about plywood and they said I could swap the SIS for OSB?

In Energy efficiency and durability | Asked By Vaseffa Fennick | Sep 5 13
3 Answers

How do you detail the exterior of an "outie" window in a straw bale home?

We plan on building a "pretty good" straw bale home in Tucson AZ, and I'm trying to think my way through a window installation. I know that most straw bale builders shape/curve the inside of their window openings to let in more light, but I don't care for this. Not only is it a pain to stuff those curves and get plaster to stay on them, but I want thick window trim (craftsman bungalow style) which is sort of impossible with curved windows. So we plan on building plywood boxes for our rough openings.

In General questions | Asked By Michael McNulty | Sep 5 13
10 Answers

Advice on insulating sheathing in climate zone 5?

Climate zone 5, western Massachusetts.

I am looking into various exterior wall systems for a two family residence and came upon the Dow Styrofoam SIS insulating sheathing:


In my climate zone with 2 x 6 framing, it is recommended that I use a minimum of 1 1/2" rigid insulation on the building exterior for a thermal break. SIS sheathing only comes in 1/2" and 1" panels but satisfies both sheathing and insulation installation in one application. Is it a bad idea to use this type of sheathing in my climate zone?

In GBA Pro help | Asked By Jon Wyman | Oct 18 11
9 Answers

Will southwest facing windows get too hot in zone 5A?

We're currently working on plans for our new house and our design and plot plan have southwest facing windows for the three kids' bedrooms. I'm concerned about the late afternoon summer sun shining directly in the windows and overheating those bedrooms. There will be some shade on the two bedrooms furthest to the south, but the corner bedroom will not get any shade for a few hours.

I estimate the biggest problem in the early and late summer assuming I decided to put horizontal awnings above the windows to block the high sun.

In Energy efficiency and durability | Asked By Erik Parris | Sep 2 13
2 Answers

Partial brick veneer

A question remains regarding insulating the 3/4 brick front (one wythe veneer) of my 1960 ranch in zone 5/6a.

This is a follow up to:


The home is sideways on a narrow portion of the lot. The 3/4 brick front is on the southern exposure, which consists of (from west to east) the family room, a walk-in closet, the kitchen, the main entry door and closet.

In GBA Pro help | Asked By J Heckmann | Sep 4 13
2 Answers

Do I need a vapour barrier on the ceiling (warm) side of the unconditioned garage in a hot humid climate?

Do I need a vapour barrier on the ceiling (warm) side of the unconditioned garage in a hot humid climate? Garage is below conditioned space.

In Energy efficiency and durability | Asked By Cynthia Zahoruk | Sep 5 13
5 Answers

Replacing a roof after foam board wall upgrade

I am about to embark on residing a house and adding 2" rigid foam board on the exterior with furring and cedar shingles on top. The roof of the house is in decent shape and not ready to be replaced (when it is ready, would like to consider adding SIPs on top to boost its thermal capacity.)

In Green building techniques | Asked By Bill Beasley | Jul 4 13
2 Answers

You recommend Siga Sicrall tape for XPS

Manufacturer lists sicrall as an interior product. Can it be used on exterior XPS?

In Energy efficiency and durability | Asked By John Waller | Sep 4 13
2 Answers

Zero-VOC vapor barrier and foam/caulk?

I have to replace the vapor barrier in my crawl space and air seal all plumbing and HVAC sub-floor penetrations.

I wonder if there's a zero voc vapor barrier and zero voc foam/caulk that can be used for these purposes.

I live in the 4A geographical area (Raleigh NC).

Thank you.

In Green products and materials | Asked By Aldo Valenti | Sep 4 13
2 Answers


Hi - I am battling serious solar heat on the west-facing wall of my FL home that is 90% windows.
Experts: what is the most efficient window technology I can get?
- Does anyone have much experience with thermochromic/electrochromic?
- How about Suspended film (SF)?
- Can you steer me to installers in the Tampa/Clearwater area?


In Green products and materials | Asked By David Sillman | Sep 3 13
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