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20 Answers

How do you insulate cob or earth bag walls in the Northeast?

Hello everyone, I am brand new to this forum even though I have been spending the last three months here reading and enjoying the comments and articles.

My wife and I are looking to build a cob house / cottage. We live in western NY where winters are snowy and there is substantial moisture. After some extensive research we do not feel completely comfortable with straw bale and are leaning towards building with Cob for all the obvious reasons. 1. it will be cheap. 2. We have lots of clay. 3. It will last, no termites, fire resistant and we can be more creative etc...

In Green building techniques | Asked By Aaron B | Sep 27 14
4 Answers

Zone 5 - Cathedral Ceiling

Hello all. Long time lurker building a new house by Candlewood Lake in CT. We are currently finishing up framing and I am getting all kinds of debate on the cathedral ceiling in my master bedroom. Above it is proposed 2 x 12 rafters and we were going to go with a vented dense packed cellulose insulation. Now I am considering adding a 1.5" layer of PolyIso on the inside.

Is there any potential to not vent? All the articles I see here strongly suggest venting when dense packed cellulose is used in a cathedral. What say you?

Is the 1.5" of Polyiso worth it?

In Plans Review | Asked By Paul Szymanski | Sep 30 14
6 Answers

Cupping shingles on brand new roof?

Hi everyone,

In General questions | Asked By Tony Johnson | Sep 27 14
8 Answers

Is continuous polyiso over plywood and concrete wall OK?

I have a 200-year-old timber-frame Cape in western Massachusetts. Last year we had Mass Save insulate the roof and three side walls with dense-packed cellulose. Unfortunately the fourth wall was an addition (70's or 80's) and already had fiberglass so the program couldn't do anything to improve it.

We are ready to tackle this final wall. Since the inside is finished we won't be removing the fiberglass but will be adding rigid foam to the outside.

From outside in our details will be:

  • 1 x 10 Ship Lap Siding (Vertical)
In Plans Review | Asked By Jamie Malcolm-Brown | Sep 30 14
2 Answers

Window & door header insulation options - Zone 5

2x6 stud walls, and the header’s have an inside and outside vertical 2x8, with the 2.5” center is empty. The outside sheathing is 1” polyiso with a foil (no OSB or plywood). I want to fill the headers before the windows are installed this week. Drying is to the inside, so no inside VB, and permeability is important. I was thinking 1.5” R6 Roxul ComfortBoard IS or 2” R8 EPS foam. I tried window/door spray foam, but the 2.5” gap was too large, and the foam just falls out to the floor. Am I overthinking this, and I can just stuff it with pink fiberglass?


In GBA Pro help | Asked By Jeff Conners | Sep 29 14
7 Answers

Proper Approach to Insulation Under Add-On Porch

We are moving into a house that has an enclosed porch area off the rear of the house. We assume it was once an open area that was later enclosed. It is now used as a pantry. Above the enclosure is a porch for the second level. The main home is solid brick (built 1910) and the porch enclosure appears to be wood framing with vinyl siding. It sits about 2 feet off the ground - e.g. you could walk under and see underneath to the joists. We haven't moved in but during the inspection I looked under and realized there was no insulation between the joists.

In Energy efficiency and durability | Asked By Historical Work | Nov 24 12
4 Answers

Finishing concrete floor (slab on grade)

The finished first floor of our house will be the slab (8"+ monolithic) and we'll be doing the work ourselves. I'm pretty sure we're going to use EcoProCote products to prep/stain/seal the floor because we've seen good reviews and reports of people using it:

Has anyone had experience using the EcoProCote products? Good? Bad? Alternatives?

In Green building techniques | Asked By Brian Post | Sep 29 14
2 Answers

How do you calculate the net free area of an attic vent?

How does a manufacturer of vents determine the Net Free Vent Area of a vent that they put on the market?

In Building Code Questions | Asked By George Sherry | Sep 27 14
4 Answers

Improving R-value of 2x4 wall in renovation with interior foam board

Hi gang,

Doing a renovation in MA, USA, and I need a little help... There's a 2x4 wall that needs insulating, and I'm not redoing the exterior of the building. It would be easiest for me to get the wall dense-packed with cellulose, then go over the whole thing with 2" foil faced foam... but I have a couple questions...

In Energy efficiency and durability | Asked By Eric Nash | Sep 23 14
1 Answer

Lawyers, Engineers and Builders Oh MY!

A place to debate or kill some time

In General questions | Asked By aj builder, Upstate NY Zone 6a | Sep 27 14
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