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3 Answers

Advice for basement wall and flooring on an uninsulated basement slab

I am insulated a basement with a very low head room and cannot add any insulation to the floor. I am insulating the exterior walls and I have a trench drain and sump on the interior perimeter of the basement. This had been installed before moving in to the house. No water has shown up in the basement in the last 4 years.

The walls are fieldstone and I intend to use spray foam and provide a dimple mat along the fieldstone wall to funnel any water into the trench at the perimeter. Not sure if this dimple mat should go up the side completely or not.

Asked By E M | Jan 22 15
63 Answers

High humidity issues in a spray foam attic

Have an interesting one here for you building science detectives.
Existing two story home built in the 1950s – Charlotte, NC (mixed humid) – approx. 3000SF. Existing mechanicals were a furnace in the crawl space with duct work distributed throughout the house and an air conditioner in the attic serving the second floor. Old batt insulation in the ceiling, wall insulation undetermined (we think none) and batts in the floor.

Asked By Danny Kelly | Jun 18 10
1 Answer

How to insulate valleys in a cathedral ceiling to avoid ice dams?

We're in a maritime climate on the west coast of Newfoundland, Canada. Climate is zoned as 6 but we have mild winters with averages around -10 C. We get warm spells followed by cooler days, not your average climate 6 winter.

Asked By OLIVIER van lier | Feb 1 15
7 Answers

Poly on interior wall

I was talking to a builder who said the key to having an energy efficient interior is to use 6 mil poly on the walls before installing drywall. He said you carefully tape around all outlets and seal off the holes.

We are in Zone 5, and although that sounds like it would be a great air barrier, I fear I would be making a mistake to follow his advice.

I am planning a house build with 2x6 studs and the following details. I will use a cheap vinyl siding, good tyvek house wrap, 3M tape on the seams, 5/8 OSB, 2x6 studs, mineral wool or fiberglass rolled insulation, then drywall.

Asked By Nicholas C | Jan 31 15
14 Answers

Minisplit setup for New Jersey, 750 sq. ft. house over crawl. Bouncing my HVAC contractor's plan off you guys.

The short. I have a 25x30 rancher over a currently vented crawl. It sets almost perfectly south facing on the 30ft long side. No tree shading on south or west. Deciduous tree shading in the east and some on the north side. It's two bedrooms one bath, kitchen and living room. Standard stick frame 2x4 construction and vinyl siding. House was built in 1963 in a post WWII development.

Bedroom1: 10x12
Bath: 5x9 rough estimate
Kitchen: 9x11
Living: 14x14 rough.
Short hallway off living room with bedrooms at the end: 4x7

Asked By Lance C | Jan 16 15
0 Answers

Using Rigid Foam on a concrete block house - Northern Ohio

I currently have a 1947 one story - exterior concrete block house(2000sf) with 2X2 interior framing filled with batt insulation. That is covered by a mix of wood paneling/drywall. The front of the house already had a 4 inch styrofoam with a textured stucco put on before we got the house. The block exterior is going to need to be painted this year if I don't do something. I do not think it was every sealed/primed/painted correctly as paint is popping off. If I do paint it correctly would I now create a moisture issue?

Asked By Tim M | Feb 1 15
3 Answers

Adding A/C to 1918 built home

My husband and I own a 1918 built foursquare home. We currently use a single 8000 BTU window A/C unit to moderate the worst of the summer heat in our zone 4 climate (Minneapolis). We have discussed installing a split A/C system or small duct central A/C system on the first two floors our home. I think I have a good grasp on the split A/C systems but know less about the small duct systems. I like that the small duct systems have less impact on the look of the house. From what I understand, attic installations are fairly common with these.

Asked By Brian Forney | Jan 31 15
3 Answers

Does code require fireproof caulk around electrical boxes & light switches?

We had a blower door test on our house following a major renovation (ACH50 = 4.56 on a 1920s Bungalow, Zone 2A). Several leaks identified, along with my plan to airseal them:

1) Electrical boxes & light switches (photo attached) - Caulk the gap between the electrical box & drywall, add a foam gasket behind trim plate, caulk plate to wall (on inside) & install child safety plugs in unused outlets

2) Base of interior door jams (photo attached) - Caulk

3) Exterior door weatherstripping (copper) - Bend back the copper for a more rigid fit

Asked By Robert Hallenbeck | Jan 31 15
0 Answers

Help with wall details

We're in a maritime climate on the west coast of Newfoundland, Canada. Climate is zoned as 6 but we have mild winters with averages around -10 C. We get warm spells followed by cooler days, not your average climate 6 winter. We heat with a wood and electric furnace.

Contractors have left us with 1/2" spruce clapboard, 3/4" rain vent, 1" rigid foam (classmate, perm of 1.0), osb sheeting, 2x6 stud with R20 batts. The plans call for poly before T&G pine... But after reading a few articles and the potential for osb turning to oatmeal: we're concerned!

What would be the best way to proceed?

Asked By OLIVIER van lier | Feb 1 15
4 Answers

How do I keep my sheathing dry?

This past summer and fall we renovated a 1950s bungalow in New Liskeard, Ontario (5700 Celcius degree days – that’s 10,260 F degree days if I’m converting correctly). We removed the interior drywall and the existing R6 batts. We also removed the siding, exposing the ½” plywood sheathing. Blueskin SA vapour barrier was applied to the sheathing from the sill plate to the top plate.

Asked By David Baerg | Jan 30 15
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