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3 Answers

Is stucco finish practical on advanced framing?

Is there a way to make 1" stucco over 1/2" plywood a good assembly over 24" c-c 2x6 framing?

In Green building techniques | Asked By brian rawlinson | Apr 3 14
9 Answers

Conditioned crawlspace and/or attic

If you need to build a home with a crawlspace because of the slope of the land and you also have an attic, what is the preferred place to put your furnace: in a conditioned crawlspace or a conditioned attic?

If you make a conditioned attic, how do you treat the space above a porch and the garage? There are obviously no ducts going to these places. Do you make them part of the envelope anyway OR you build walls to exclude them from the conditioned space?

Thank you for your time and help.

In GBA Pro help | Asked By Liliane Tricot | Apr 1 14
1 Answer

Passive heat recovery - passive exhaust and supply

Ventive's passive ventilation and passive heat recovery solution



At first I wanted a fresh air intake warming solution for passive inlets that are balancing/supplying a hybrid, exhaust-only situation. I looked for a way to pre-warm the incoming air for free; to off-set the BTU's lost through the exhaust. There are some "warm wall" designs and "snaked" inlet piping designs that act as passive heat exchangers to incoming fresh air.

In General questions | Asked By flitch plate | Apr 3 14
9 Answers

Wall section - help with air and vapour barrier

I am using a commercial insulated metal panel system to insulate on the exterior of the sheathing. Panels are arranged horizontally (40" high and up to 40' long but I'll likely cut to 10' as they would be too heavy) and secure through plywood to 2x6 studs using metal self-tapping screws.

Appreciate the community's help in determining best location for air and vapour barriers / retarders in this assembly.


In Plans Review | Asked By Jerry Chwang | Apr 2 14
2 Answers

How to seal a ceiling with insulation above (in Maine)

To Martin Holladay:

Last week you gave this reply to a question about putting cellulose
insulation on top of fiberglass batts in new construction. You have answered
that in full and I thank you for it. However, you made a further comment as
follows: " I hope, however, that your builder remembered to do a careful air
sealing job at the ceiling plane before any insulation was installed."

Please let me know more particularly what should have been done to the
ceiling to seal it properly.

The only air sealing that I know about is that the fiberglass batts have

In GBA Pro help | Asked By Robert King | Apr 3 14
1 Answer

Air and vapour barrier questions

Wanted to confirm I have correct understanding:

1. It is ok to have 2 or more air barriers in an envelope assembly
2. It is not ok to have 2 or more vapour barriers, in case moisture got into the wall, it would not be able to dry out.
3. A vendor told me that vapour diffusion only occurs 'in a straight line', i.e. perpendicular to wall or roof. If I have a shiplapped layer, the vapour will not follow the serpentine profile to go in or out of the house.

In General questions | Asked By Jerry Chwang | Apr 2 14
1 Answer

I'd like to install recessed lights in my walk-in closet. Can I use non-IC lights?

There is thermal insulation in the attic. Is it possible to use NON-IC lights and create a border (kind of fake ceiling), if it is possible, what's the mark spacing between this border and the insulation.

In General questions | Asked By Natalia Lucar | Apr 2 14
1 Answer

EPS and butyl rubber

I had a question regarding a roof SIP and GRACE Ultra Peel & Stick - Butyl Based Membrane. The SIP has an EPS core and my concern is when a fastener punctures the peel & stick membrane, the rubberized butyl gets into the EPS core. It is a rubberized asphalt type of product. Since petroleum and EPS don't mix, will this cause a problem?

I read that petroleum based products can eat away at EPS and literally melt it. Will this be a problem with GRACE peel & stick on the SIP roof with an EPS core?

In Green products and materials | Asked By Peter L | Apr 3 14
1 Answer

Lineset losses?

Has anyone tried to quantify heat loss through the outdoor parts
of typical heat pump lineset installations? Does it matter much?
It occurs to me that some token amount of insulation is applied
there, but is it sufficient? Especially on the vapor line, which
runs pretty warm in heating mode and the farther the lineset goes
before coming indoors, the more it's exposed to a high delta.

Trying to ballpark it, assuming typical pipe insulation with about
a 1.5" outside diameter and half an inch thick, what is that stuff
usually, about R-3? Assume a ten-foot length running outdoors to

In Mechanicals | Asked By Hobbit _ | Apr 2 14
4 Answers

Extruded polystyrene

I am interested in using your "cut and cobble" method for insulating the walls of my addition. I live in zone 5 and plan to use 2" of extruded polystyrene and 4 1/2" of dense pack cellulose. Are there any negative effects in using readily available uncoated extruded polystyrene with a perm rating of 1. ? The coated extruded poly seems to have a perm rating of .1 but I cannot locate any ( Dow is no longer making it).

In Energy efficiency and durability | Asked By Rolf Reiss | Apr 2 14
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