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7 Answers

Insulation and vapor barrier with tongue and groove

I am in Southern Indiana which is zone 4a. My wall is this from outside in...Hardie board lap siding, house wrap, 7/16 OSB. That's where I am now. I have 2x4 walls.
If money were no object I would do 3 1/2 inches of closed cell foam. 2nd choice would be and inch or so of closed cell on the OSB and then net the walls and use cellulose. Even an inch of foam is very expensive so the cheap option is netting the walls and blowing in 3 1/2 inches of cellulose.

In Energy efficiency and durability | Asked By Mitch Groves | Dec 8 13
2 Answers

Insulation and ice dams

We are getting ice dams on the south and west sides of our home. We have plenty of insulation in the attic but on those two sides (south and west) there is a covered porch. There is no insulation on the soffit that covers the porch and of course no insulation in the eaves.

The porch is about 6 feet wide and runs the entire length of the south side of the home (the front) and the entire length of the west side. The east and north sides only have eaves which are less than 12 inches.

In GBA Pro help | Asked By Jared Bennett | Dec 9 13
1 Answer

I have an ICF house on Vancouver Island with a Open Joist/ T&G Fir roof

The T&G Fir is attached to the open joist through the T&G Fir, above the T&G is a layer of Glued Blue Skin followed by 3 layers of High density foam boards (8*4) 3.25x2 with 1x1..25 cross layered there is 5/8 Ply screwdown with long screws to the joists, The tar paper and duroid roofing is attached in the normal manner.
When we moved in (3 years ago) no issues materialised but where the T&G extends over the wall (outside) we are now seeing evidence of condensation when the temperature drops arond 0c. I suspect the T&G has dryed out and shrunk over time

In Energy efficiency and durability | Asked By Alan Webb | Dec 9 13
1 Answer

How to deal with odor coming up from basement?

I live in Nova Scotia. Moderately hot and sometimes fairly humid summers, cold winters although very variable. Similar to US North East.

In Energy efficiency and durability | Asked By David Monaghan | Dec 8 13
3 Answers

Obscure OSB air barrier questions

In general, is an air barrier composed of 7/16" OSB similarly effective as a 5/8" OSB air barrier, assuming all installation details were the same for both?

I have seen people using caulk and without caulk when fastening OSB to structural lumber, I assume that the concept with the caulk is that they're trying to seal the penetrations through the OSB?

Are the air leakage through holes created (and filled) a significant source of air leakage?



In Energy efficiency and durability | Asked By Chris Barnes | Dec 9 13
1 Answer

OSB vs. Zip System

Quite often I here about the problems with osb and moisture. It holds moisture, it falls apart, etc... Does this apply to zipsystem sheets or does the coating and glues they use put it in a different category? I have had to replace failed/rotted osb in the past and I switched to zip system because I was told this would not happen. Is this true???

In Green building techniques | Asked By darren williams | Dec 9 13
15 Answers

Insulation Re-do

I am an architect working on a 2 BR/2BA high end addition above an existing garage in the mountains of Colorado. The exterior walls are 2x6 walls, roof has 2x12 rafters, floor is 11-7/8" TJI's with 1 1/2" of gypcrete for radiant heating and tile floor. Garage below is heated and insulated. The contractor just insulated the new space and did it differently than spec'd. We caught it before drywall and he is going to go back and make changes to bring things to what was spec'd.

In GBA Pro help | Asked By Rick Dominick | Dec 6 13
1 Answer

access denied

How do I get access these sites?

In General questions | Asked By Daniel Nelson | Dec 9 13
1 Answer

Should I or can I safely insulate interior ceilings?

I own a poorly insulated home and would like to insulate the ceilings with 2" of Dow foam? I live in Zone 5A. The ceilings and walls are lath and plaster. My attic space is also not insulated. My plan is to also insulate the exterior walls with Dow foam and install new siding. The exterior walls have painted siding but NO sheathing.


In Energy efficiency and durability | Asked By Michael Craig | Dec 9 13
1 Answer

Ceiling construction in tropical fish wholesale facility

I have recently hired on as a maintenance man in a Tropical Fish Wholesale facility. Probably 1000 fish tanks and 100% humidity. After looking at the Hodge Podge of insulation boards fastened to the sheetrock Ceiling for 3 months now, (This is to keep sheetrock from falling down, and using this same method to repair 2-3 spots) I've decided to investigate the attic situation. Worst fears have been realized. It is Literally raining in the attic. Plywood covered with ice and water. Cellulose Insulation totally soaked. Flexible air ducts full of water.

In GBA Pro help | Asked By grant brockey | Dec 8 13
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