Community: Energy efficiency and durability

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

Low-slope roof

I am building a PGH and I have a 32' run of unvented, low-slope roof that we will start framing out shortly. The interior stack-up is gypsum, 2x3 service cavity, Siga Majrex air and vapor control layer (let's vapor out of the cavity, but not in), 2x12 joists, dense pack cellulose between joists, 3/4" Advantech seams taped with Wigluv. I was planning on using a unvented nailbase product that has 4.5" of polyiso with a layer 1/2" osb attached to the top. I am in Zone 4 and this will provide more than the required .31% of exterior to total r-value even if I de-rate the polyiso r-value to 5.

Asked By Jonathan Lawrence CZ 4A New Jersey | Aug 18 17
3 Answers

Mild climate; Expensive cellulose - what to do?

I am getting ready to go to Engineering for a new house in Raleigh, NC.

HDD - 3247 and going down....On border of zone 3 and 4. Technically in 4 but 20 miles from the 3/4 border.

Being in the South, everyone worries about cooling but we usually have 3x the cost in heat (based on last energy audit).

Asked By user-6902085 | Aug 18 17
1 Answer

Chimney chase insulation

I have read a lot of articles and forum posts about this, but there is not a lot of consensus, and each answer seems very case specific. So, here is my case! I am installing a RSF Focus 320 [Editor's note: This is a manufactured fireplace with a glass door; the fireplace is designed to burn wood.] in a new construction home in NC with outside combustion air and a hookup to our HVAC system for distributing heat.
http://rsf-fireplaces.com/en/focus-320-woodburning-fireplace#mc

Asked By Kevin Spellman | Aug 18 17
4 Answers

Best waterproofing to be used over ICF walls

Just put up the ICF walls and filled with concrete on our well insulated house in Zone 7. Was planning on using Grace Bituthene. It seemed to work well on another storage building constructed with the same ICF walls.

The area is properly drain tiled, and the house is in a fairly well drained area to boot.

Just wondering if there is maybe something better out there?

Thanks!

Steve

Asked By Steve Lenertz | Jun 29 17
4 Answers

Turning a barn into a house: Roof quandary

Hi GBA community!
I am in the midst of converting a not too old timber framed barn into a house for a friend/client. It's going well, and we have a good plan for the thermal enclosure, in my opinion. There's a small matter of the roof, though.

Asked By David Bailey | Aug 16 17
2 Answers

Average quality built homes needing makeup air because they are airtight

I have a question in regards to homes being built (not necessarily green homes) that are subject to the new energy code with air sealing and blower door tests. These homes are being built with average, code minimum building materials and after a blower door test it is showing the house is tight enough to require make up air.

Seeing as these are not green homes, there was no plan in place ahead of time for a system to bring fresh air into the house. Are you seeing this as a problem in other states as well?

Asked By Brian Ducharme | Aug 17 17
4 Answers

Flat residential roof?

Residential architecture has been leaning towards flat roofs, from what I've seen they always leak!! What is the best way to insulate, and protect from ice & water breaching the asphalt torch down?
Zone 3
Thanks
Kris

Asked By Kris Currie | Aug 17 17
6 Answers

Advice on tight building

I have my house rough framed, we are framing out the roof now. Climate Zone 2 ( Just north of Austin). 2x6 conventional framing 16 on center, and has the typical double headers around windows etc. I am nearing having to lock down my decisions on sheething, insulation etc. I have been considering using Zip R for a couple reasons.

1. breaks my thermal mass, that I have plenty of
2. Weather and air seal.

It is anything but cheap, I am looking probably 7000 for the 1inch.

However I am looking at other options

Asked By Sleaton | Aug 15 17
9 Answers

Interior Rigid Foam on Solid Masonry Walls--Am I Going to be Okay?

I have bought a home with solid masonry walls (CMU block interior wythe, concrete "crick" exterior wythe, plaster on the interior of the wall). I would like to add rigid foam insulation to the interior, with a gypsum board interior finish. The foam would be 1.5" XPS (caulk around sheet perimeter, foam and/or tape between sheets) , then 3/4" furring strips 24"OC, affixed with Tapcons to the block, with 3/4" XPS between the furring strips. Attach drywall to the furring strips.
The home is near Dayton, Oh (extreme southern part of Zone 5).

Asked By Mark Waldron | Aug 15 17
12 Answers

Is it worth the cost of adjustable-tilt racks for PV?

Currently we are looking at getting a 6kW PV system which will plan on installing on a outbuilding or a pergola. I want to know if it's worth the cost and possible headache of have the PV on an adjustable tilt change it the angle four times a year; December, March, June and September?

Asked By Arnold K | Aug 3 17
Register for a free account and join the conversation


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