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1 Answer

Insulating a spalling foundation

A portion of a near--term retrofit to my 1925 cape calls for insulating the poured foundation walls. Before hiding any foundation issues with 3" of spray foam, I'd like to solicit for some guidance. Here are some foundation facts not already mentioned:

77" total inside height
8" thick
22" exposed above grade on East side
33" exposed on West
Moderate spalling along all lower foundation edges to ~8" high

In Energy efficiency and durability | Asked By John McMurry | Nov 26 12
7 Answers

Tankless water heater - attic or crawlspace?

Climate zone 5 -- Indianapolis, Indiana. I live in a very small house, 1000 sq ft., so I want to free up the large closet that currently holds the furnace and tanked water heater, both natural gas. I'm chucking the ducted hvac system in favor of a ductless mini-split and converting the tank water heater to tankless. I want to put the new water heater in either the attic or crawlspace. Is one location preferrable? Do I need to purchase a unit designed for outdoor use?

My goal is to move the laundry out of a bedroom and into that large closet space.

In General questions | Asked By David Martin | Nov 25 12
8 Answers

Effective Energy Star dishwasher choices?

Hello GBA community:
I often get questions involving dishwasher selections. Traditionally, my advice was, naturally, Energy Star. More recently, I've questioned this general advice given the user experiences that I've witnessed. The problem statement is thus: I'm seeing wasteful dishwashing practices in all of the homes that I'm involved with. The homeowners all have some brand of high-end, Energy Star rated dishwashers, and all of them pre-wash their dishes because the dishwasher just doesn't do a sufficient job at washing dishes by itself.

In Green products and materials | Asked By Lucas Morton | Nov 20 12
9 Answers

Air barrier material and location

I have several questions involving wall systems. I live in Michigan, Sanilac county (zone 6). 7133 HDD, 477 CDD. We are about 1.75 miles inland west of Lake Huron.

I am looking to build a ~1400 Square foot ranch with a 2+ car attached garage.

In Green building techniques | Asked By Shane Fairman | Oct 26 12
1 Answer

How long does it take to dig by hand a 1m deep, 20cm wide trench in clay

We need to replace the 80 year old clay sewer line that connects our house to the barrel sewer. The line is cracked, tree roots have got in, there's a break. The plumber recommends poly as a replacement. I had a guy in with a camera and transponder who's videoed the pipe interior and located it for me. As an aside, that is great technology.

In Green building techniques | Asked By David Coote | Nov 26 12
4 Answers

Detachable shed

We're planning to build a garden shed in our backyard. The shed will be made primarily from timber. One spot we had in mind for the shed is in an easement on our property for a barrel sewer that runs along the back of the properties on our street. The sewer is about a metre deep. This is deep enough that if we built the shed on stumps or a slab we would be unlikely to disturb the sewer. But the management authority for the sewer reserves the right to dig up the easement if necessary to work on the pipe. So if we had a shed on the easement this might have to be demolished. Not very green.

In Green building techniques | Asked By David Coote | Nov 24 12
4 Answers

Basement wall insulation

I recently glued 2' 4x8 (XPS) rigid foam to my basement walls. I cut pieces to fit between the joists and along the rim joist. I put pieces on top of the cement wall, and then foamed around all those pieces, and the bottom of the 4x8 sheet. I then installed a 2x4 wall in front of and touching the rigid foam.
Do I need to put unfaced batts in the bays ?


In GBA Pro help | Asked By Deb Malloy | Nov 26 12
10 Answers

Which closed-cell foam insulation to choose?

With all of the types (and dealers) of closed-cell foam out there, how do you choose?

Lapolla and BASF seem to be two of the options I have. Is either one safer, better, more Green??

In Energy efficiency and durability | Asked By Moya Mim | Nov 19 12
2 Answers

Can I use spray foam insulation on attic trusses on an ICF home?

I am building an ICF home using Reward walls, footings to rafter, with no sill plate, but using hurricane straps. Walls are 13" with 2.5' on each side for insulation and 8" of concrete fills the cavity.

I have attic trusses and am unsure how to best insulate this without having moisture problems with this tight of a home. It looks like I can use a minimum of 2 inches of spray foam and then fill the rafter top cords with batt insulation. Does the entire rafter cavity need to be filled? The trusses are varing lengths with the open living space just under 14 total feet.

In Green building techniques | Asked By Jim McKay | Nov 20 12
3 Answers

Crawl space insulation questions

I’m going to be converting my crawl space to a sealed, conditioned space. The concrete block walls will be insulated with rigid foam. I’ll be using TherMax, as I understand that unfaced rigid foam does not meet the ignition barriers of the IRC. I am also planning to use spray foam to air seal and insulate the rim joists (per Fine Homebuilding No. 189 , September 2007). Interestingly, I’ve never seen any discussions about ignition barrier for the foam for the rim joists. What’s the story here?

In Building Code Questions | Asked By Michael Hansen | Nov 24 12
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