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9 Answers

Covering exposed rigid foam insulation on foundation

I am building a new house and plan to have 4 inches of ridged foam on the outside from the foundation to the eaves. My question is how to cover the portion that is above grade level, but below the siding?

In Green building techniques | Asked By Eric Heerdt | Feb 7 13
2 Answers

Do unvented cathedral plank ceilings require spray foam?

I am designing the envelope of a 600 sq. ft. house to be built later this year. It has a cathedral ceiling with a few irregularities that would prevent proper venting. I was planning to use cellulose between the rafter bays, insulate on top of the roof sheathing with rigid insulation, and use the airtight drywall approach to keep interior house moisture out of the cellulose. However, my wife and I want to build the house in a cottage style with wood planks on the walls and ceiling.

In General questions | Asked By Eric Matsuzawa | Feb 10 13
1 Answer

How to insulate my uninsulated house?

I live in a house in Kamloops, BC (40c in summer, -20c in winter, dry climate) that was built in the early 1950's. From inside out: Drywall, Foil-backed paper, 2x4 framing, Drywall (local plywood shortage at the time of construction), Tarpaper, Wood siding. There is no insulation in the stud cavities. The exterior is due for replacement, and I would like to add some R value at the time. I have researched PERSIST designs, and think it would work, but have a couple of concerns.

In Green building techniques | Asked By Ben Colver | Feb 9 13
3 Answers

Adding insulation and new ductwork in a Kansas attic

I live in an 1800 sq. ft. 20 year old single story ranch on a slab. I'm located just outside of Kansas City, KS in climate zone 4A. I want to increase the attic insulation, but before doing so, I wanted to improve the duct work in the attic since the builder did a really poor job with both the design and the install.

In General questions | Asked By Roger Marrs | Feb 8 13
10 Answers

ERV Installation

Folks ... just built a new fully enveloped home. Being concerned about air quality, I had an ERV system installed. We have dedicated stale air exhaust but the fresh air intake is plumbed into the Air handler return. When the ERV runs, the fresh air seems to be coming out of the return filter and not the existing supply side ducting. I would prefer not to have to run the air handler fan all the time. Anyone else experience this issue ?


In Mechanicals | Asked By Johnny Hodges | Feb 9 13
0 Answers

Good blog by a home inspector

Many of you may appreciate this frequently updated blog by a second generation home inspector.
Good content and lots of descriptive pictures.

My colleague contributed the latest post on the 'unintended consequences of adding insulation'


In General questions | Asked By j chesnut | Feb 8 13
9 Answers

Water and Wood at Micro and Nano Scale

here is a micrograph of white oak

I am trying to verify the scale
Are the units in Microns?
does the visual scale in the lower left corner indicate 100 microns?
Or in other words 100,000 Nanometers?

In General questions | Asked By John Brooks | Sep 26 10
1 Answer

Double-stud walls and air barriers

I am working on the design of a double-stud wall residence (approx. 12" thick) in climate zone 6b and am currently detailing the air barrier & estimating costs on a variety of different products/approaches.

The insulation will consist of dense pack cellulose and the exterior cladding will be lap siding on a ventilated rainscreen in some areas and vertical board & batt (basically a ventilated rainscreen on its own) in other locations.


In Green building techniques | Asked By James Kennedy | Feb 8 13
9 Answers

Warming passive make-up air for exhaust only ventilation

I need advice on where to locate and how to condition (or at least protect occupants from the cold flow) incoming make up air. I need to bring the rigid vent pipe on the exterior (unconditioned crawl space) under the floor and enter through my 12” insulated floor baysup. There is no suitable wall or soffit entry point for the intake. I can install more than one intake if necessary.

I have 3 draws: (1) an electric clothes dryer, (2) a single 80 -120 CFM bathroom exhaust fan and (3) a 120 CFM range hood; plus a small wood stove. The Prestige boiler is direct vented.

In General questions | Asked By Oak Orchard | Feb 7 13
2 Answers

I am working on a single family house in Climate Zone 5 in New York State.

The first floor is a suspended concrete slab with radiant heat over wood framing. The basement is totally buried with the exception of the top 6". It's covered in 2" of rigid insulation. It will be heated but to a lower temperature than the first floor.The only opening into the basement is a bilco door.

I had originally specified 1" white Dow to be used under the first floor joists but am wondering if I can specify instead one of the radiant barrier materials in the interests of economy. Thanks.

In Energy efficiency and durability | Asked By Linda Gatter | Feb 7 13
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