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18 Answers

Residential frost-protected shallow foundation in central Mass.

We are planning to provide a monolithic pour frost-protected shallow foundation (FPSF) for a single story 1300 sq ft 2 bedroom home in central MA. Air Freezing Index is 2000. I have read through many different case studies, research papers, codes, etc and there is a bit of conflicting and locale-specific info so I am looking to see whether I understand what is required here. I am a newbie owner-builder. Any constructive criticism would be appreciated, but I don't want to foment any religious wars.

Asked By Kenneth Gartner | Sep 2 16
8 Answers

Ranch vs 2-Story Home

Generally speaking, if one is looking to build a 1,600 sqft home, which provides the better energy efficiency and less expensive route?

Having 2 levels of 800 sqft each seems like it would be better from an energy standpoint since there is less roof area and everything is compacted in a smaller pad. Cost wise there is less roof area to frame, insulate and install a roof on with a 2-story. There is probably some cost savings in flatwork and foundation with a 2-story since the footprint is smaller.

Asked By Peter L | Nov 16 17
6 Answers

Roof membrane and live vegetative roof

Hey all,

So after Material quotes and city grants etc, it looks like its going to be viable go me to do a live vegatative roof (green roof) on the flat roof I've recently built.

now I'm thinking about what roofing membrane to put on, to go under the green roof. I am considering things like cost, longevity, ease of install, potential for leaks etc.

I'm in climate zone 6. My potential roof assembly is as follows:

9.5" I joists with R31 rockwool batting
3/4 plywood decking
6" polyiso at R34
1/2" roofboard
Roofing membrane ***
3" green roof assembly

Asked By Jamie B | Nov 18 17
4 Answers

Insulate a Cabin to last

Martin - I've learned a tremendous from you & GBA. This is a 1st asking a question. I'm also an engineer & lic Home Inspector, and I see what happens to homes.
I'm current building a cabin in northern Hayward, WI (Zone 7). I'm on a slab, 20'x26', 1 1/2 story, 2x6 walls 16" OC. I had a local carpenter put up the shell, and the rest is up to me. The cabin is sheathed in OSB, Tyvek, Fascia/soffit, and Anderson windows & door are in. I installed kraft faced R19 Batts in the walls (drywall & siding are not yet installed).

Asked By Dan Musielski | Nov 16 17
2 Answers

GBA Construction Details criticism & question

First, I thoroughly appreciate the effort to organize and share a large volume of quality construction details on GBA. Excellent information.
However, I'm disappointed that the .dwg versions of details are incredibly time consuming to work with for the following reasons:

1. Details and objects are completely exploded which makes them very inefficient to work with and revise. Leader arrows are not even singular entities and are exploded into 4 separate objects. Hatches are often dozens of exploded objects which is painful to select in order to edit.

Asked By Spencer Decker | Nov 15 17
4 Answers

Best way to insulate attic

My attic currently has R19 foil faced fiberglass batts installed. I would like to air seal the entire attic and re-insulate with blown in cellulose.
The original plan was to cut EPS to fit between the stud bays and seal with great stuff, followed by the fiberglass and blown cellulose. From my understanding, EPS or any rigid foam is not worth the labor for this particular application.

Should I remove the fiberglass batts, caulk/foam the seams and openings, and then reuse the fiberglass followed by cellulose?

Asked By craziekeiichi | Nov 13 17
5 Answers

Please Help!!! Dimple membrane a necessity?

Asked By Rasheed Warith | Nov 14 17
10 Answers

Question on direct vent fireplaces

I am gut renovating and expanding a circa 1920 cottage. I am trying to get as close to net zero as I can. I am an architect fairly well-versed in the principles and techniques of net-zero, DER and Passivhaus my firm having designed and built two Passivhaus and 13 net zero homes, all of which have had their performance measured and verified. The point of this bragg-y credentializing is to head off the inevitable finger wagging that usually comes upon mention of the very idea of including a fireplace in a home that aspires to net zero. I get it. Not a good idea.

Asked By user-6954517 | Nov 18 17
8 Answers

Sizing a ductless minisplit for heating

Hi all,

I'm going to install a ductless heat pump. I settled on LG Art Cool Premier (HYV1 or HYV2). Now I need to figure out system size, and there is too much info.

I have 550 sf addition built in late '80s, which is a split lever open space, and is VERY cold (i've attached some photos)!

It has a large french door (8x10' glass, 3 sections), 7 windows, and 5 skylights. All are double glass.

Asked By Levab | Nov 16 17
8 Answers

Petrol-free home: Petrol-free housewrap

So I've got a plan that promotes petrol-free materials throughout the lion's share of the rehab of my shed, which is a lead-in project to the rehab of my house. It involves now a metal roof; Pavatex as a insulation above the roof rafters and Roxul between the rafters; Airkrete in the wall cavity; and Foamglas beneath the Rosendale Cement-based concrete slab.

Main remaining urgent challenge to get the plans to the buildings department ASAP as far as I can tell: "house wrap" "vapor barrier" situation.

Asked By Gregg Zuman | Nov 15 17
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