Community: Energy efficiency and durability

Q & A Instructions

[Click map to enlarge]

The 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!

2 Answers

Roof structure, insulation and lighting

I am planning a new home in northern Idaho climate zone 6 and have some questions regarding the roofing structure/insulation and lighting within this system. this will be a mostly cathedral ceiling with a flat part across the middle in which I intend to put the lighting and ceiling fans. The thought is to keep these items out of the insulated roof. It will be a non vented roof. I have attached two drawings to help illustrate my thoughts. I would like to build the roof as follows from top to bottom:
1. Dutch Seam metal roofing
2. 2x4 furring strips

Asked By Kyle Rice | Apr 28 16
2 Answers

In process of utilizing 5/8" fiberglass shell for a small building

Is wrapping in EPS or XPS advisable; should foil surface (vapor barrier) face inward to building or outward to ambient? Is Ceramic Paint a viable alternative since Fiberglass Shell is a homogeneous structure. Electrical and plumbing to be installed on interior side of shell. if so referral to independent (i.e ASTM) applicable studies is appreciated...Thank you, Tim

Asked By Tim Boyle | Apr 27 16
2 Answers

Any vented attic air sealing tricks? And recommended R-Values? Blown fiberglass?

I am building a home in climate zone C4 and am getting ready for insulation at last. I have wrapped the house with a layer of 1" xps already, but am getting ready for the rest. The local insulation contractor is pushing blown fiberglass over blown cellulose, what do you guys think about this, I have heard it settles less. Most of the house has cantilevered scissor trusses. Do you guys have any good practices for air sealing around all of the electrical lighting boxes (not cans) that I have installed in the ceiling?

Asked By Kail Zuschlag | Apr 28 16
7 Answers

Why do I feel cold on my right side when I sit near my new windows?

I got triple-glazed windows installed, but I seem to feel cold on my right side of my leg sitting next to the new windows. Everything seems to be sealed.

Can someone give me a explanation, please?

Asked By Scott Brady | Apr 25 16
17 Answers

What's the payback?

I read here over and over again the recommendation that a house should be built tight and ventilated. The house should also have insulation levels over what is required and what is typically done. I'm good with that if it makes sense. I'm sure someone has done some studies in various climates and calculated the savings and the simple (or not so simple) payback for the upgrades, but I'm not finding it. What makes sense?

My case, climate zone 5, new 2000 SF home, cheap natural gas. No AC. Colorado, lots of sun. Conservative habits, turn off lights, keep tstat low.

Asked By Brad Haack | Apr 24 16
6 Answers

Insulating existing slab on grade - need for sleepers?

After completing a strategy for insulating my slab-on-grade floor (which sits on sand ONLY) as part of a major building renovation in Zone 5a, I discovered the GBA construction detail for the same situation here:

The GBA solution calls for treated lumber sleepers in each layer of insulation.
a) Given the high compressive strength of XPS, what purpose is served by the sleepers?

Asked By Dean McCracken | Apr 20 16
2 Answers

HRV intake below grade?

Is there any benefit to running X amount of pipe below frost grade to pre-heat/ cool intake air to an HRV? Would this not increase the operating performance of the HRV?

Asked By Kris Currie | Apr 26 16
1 Answer

What do you think about Mylar-wrapped Styrofoam board for a housewrap / thermal barrier and radiant barrier?

I would like to know if there is any reason this material might either cause a problem with the envelope or if it will be effective as and radiant barrier (both directions) or not.

Asked By Mickey Thompson | Apr 27 16
7 Answers

How best to insulate in DFW area (zone 3) - new construction

Hey guys,

Asked By Shawn Tucker | Apr 25 16
8 Answers

Best furring strip over exterior foam to hold Hardie siding?

Ok, this has come up before and I want to get final recommendations from those who have done the work in the field as my foam board is almost finished.

I have attached 2.5" of recycled EPS to the exterior over my drain wrap. Windows are INNIES and are flashed well. As a point of fact, the Tyvek brand tape worked and adheres excellent to the EPS. I have some 3M all weather tape but the Tyvek tape works great and is easier to work with.

Asked By Joe Suhrada | Apr 26 16
Register for a free account and join the conversation

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