Community: Green building techniques

[Click map to enlarge]

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

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!


5 Answers

R-35 wall assembly for a 4C Marine climate zone

I am about to build on a 85" rainfall, 6000 HDD and no cooling system (I can withstand a little heat in summer)
http://en.climate-data.org/location/147654/

I'm thinking of (from outside in)
* 1" wood siding
* 1" of air gap with 1x3" furring
* asphalt paper as WRB and air barrier
* 3" 2pcf EPS as R10 sheathing,
* A 10" double frame wall filled with a total * of R-24 polyester insulation
* asphalt paper as air barrier and vapor retarder
* 3-4" interior wood finish

(see attached image)

Asked By Jose Castro | Oct 29 14
2 Answers

Vapor retarder location

Hello,

Asked By Ryan Lambert | Oct 29 14
2 Answers

Basement slab retrofit questions

I have an older home built in the 1950’s. I’ve insulated the basement walls with rigid foam and a stud wall with batts. This has made the basement more comfortable, but I still have a lot of moisture in the air based on the dehumidifier that I run frequently. I’m fairly certain that the existing slab must be un-insulated and is missing any poly or other moisture barrier under it.

Asked By Mark Fredericks | Oct 27 14
5 Answers

Double wythe CMU vs. Thermomass

After living in Europe for several years I have become a fan of concrete. I build in the Southeast and have mainly used concrete commercially and as stem/foundation/retaining walls and for slabs in residential.

Asked By leo kloop | Oct 22 14
12 Answers

Thermal energy storage

~3900 square foot house.

I am thinking of building a water based TES tank using ICF in a crawl space.

The plan would be to use RV antifreeze in an active (pump) circulating heat exchanger that sits at the bottom of a tank of water. Domestic water supply would pass through another heat exchanger that sits at the top (for stratified water column effects) inside this tank and preheat water for radiant hydronic boiler and domestic hot water.

I was thinking 12'x12' @ 6' tall for a 864 cubic foot / 6463 gallon tank.

Asked By Jim Pancanke | Oct 21 14
4 Answers

PERSIST vs REMOTE vs SIP ?

We are building a new house in MN (6b), considering various wall systems, and trying to get a handle on the pros and cons of each. Thus far we have:

SIP Pros
- Better known construction method, easier to find carpenters, ...
- Well documented construction details

PERSIST Pros
- Seems like it would be easier construction than SIP.
- Easier to get all details correct.
- Provides significant interior space in attic for ducting, extra room, storage areas, etc.
- Chemical elements (foam, osb, etc) on outside of air/vapor barrier

REMOTE Pros

Asked By Walker Angell | Oct 21 14
34 Answers

Options for high R-value above-grade walls (R-80)?

To make a long story short, my above grade exterior walls need to be at an R value of 80. This is to meet Passive House standards for a new residential house in a very demanding climate.

I am currently planning on using SIP's of some sort. But even the best of those only get me up to around R-50 though. Any thoughts on ways to get to R-80 while still being cost effective and keeping the size of the wall to a minimum?

I have found a number of options myself, but was curious if anyone else had thoughts or suggestions to meet such a high R value for a wall.

Asked By Tom Schmidt | Sep 19 14
1 Answer

Vented roof insulation

For a vacation home in a 5b zone, does it make sense to put exterior rigid insulation (1" xps) under a standing seam metal roof? This will have a vented attic with no mechanicals up there. I anticipate blow-in on the ceiling deck.

Asked By Robert Holland | Oct 16 14
10 Answers

Roxul Comfortboard - disadvantages?

I'm intending on insulating my 1950's Cape style house with exterior insulation. I've been planning on following the CCHRC's REMOTE wall assembly with an air tight membrane over the sheathing and 6" of EPS foam (2, 3" layers) then furring strips and siding.

Asked By Mark Fredericks | Oct 14 14
9 Answers

Building science options

looking for advice on options on getting into building science & green renovation ---- it seems there is still a disconnect between the building science research and the builders in the field.

Quick background on me --- I have a Chemistry degree and taught the subject for 8 years before leaving the field to be a remodeling contractor --- so I am very interested in the science behind renovating from an energy standpoint.

Asked By Jason Schatz | Oct 5 14
Register for a free account and join the conversation


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