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13 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
Bedroom2:10x12
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
6 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
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
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
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
5 Answers

Is 4" of foam worth it?

I am building an addition onto my house in climate Zone 4 (central Missouri). Part of the plans of the addition are trying to incorporate having 2x6 construction of the addition next to a 2x4 framed original construction.

I have decided to allow the 2" difference in framing to stick out to the exterior of the south side of house with the intention of having 2" of foam on the 2x6 wall (which appears to be enough to prevent condensation) and adding 4" of foam to the 2x4 walls.

Asked By Michael McArdle | Jan 30 15
7 Answers

Freeze risk for a heat pump water heater in an unconditioned garage

I have an unconditioned garage with a gas water heater in climate zone 5B. The garage is unconditioned, but insulated (R-15 whole wall, no slab edge or sub-slab insulation), and obviously has some exposed plumbing in it. Right now, the temperature in the garage doesn't get low enough to present a freeze risk, probably aided by the water heater's standing pilot light and hot metal flue. But if I replace it with a heat pump water heater, the unit's going to be continuously cooling the room, right?

Asked By Nathaniel G | Jan 31 15
0 Answers

Open cell insulation in a vented attic

We recently hired a contractor to renovate our home. To make a long story short, we have a vented attic system, where true vents were installed along the exterior between the roof rafters. Then open cell spray was applied, with a vapour barrier poly then applied. Is the insulation at risk of moisture because of the true vents being applied?

Asked By Ginny Cosgrove | Feb 1 15
1 Answer

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
2 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
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