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16 Answers

Heat-pump water heater in Canada?

I live in Nova Scotia in zone 6B. We're thinking of installing a heat pump hot water heater (my husband would do it himself) and not sure of how efficient it would be. We just bought the house, and the inspector told us (he used an infrared camera) that the house is well insulated. It was a Kent Home built in 1986; a split entry. We are going to have someone install a mini-split ductless heat pump in the living room upstairs. The rest of the house is heated by baseboard heaters. We pay 14.8 cents per kwh (no time of day billing).

In Energy efficiency and durability | Asked By Sarah Poulin | Jan 25 16
3 Answers

Vinyl siding over Zip system

If you intend on installing vinyl siding over zip system, should you be using galvanized or stainless fasteners to install the zip sheathing? I am at a point of starting sheathing with zip system on a new build and would rather not install a WRB though I am concerned that using bright nails will rust and maybe eventually make its way onto the siding. Has anyone dealt with this in the past? Any thoughts or advice would be appreciated.

In General questions | Asked By Brian Ducharme | Apr 23 18
6 Answers

Are these calculations wrong?

Hi all; we're building a 2300 sqft ranch with a basement for a total of 4600 sqft of conditioned space in climate zone 4-A. The slab is 4" concrete with R15 under it. The foundation walls are 8" concrete with R15 against them. The rest of the walls are aerated concrete with insulation for a minimum of R21.5 - 11.5 for the block and another 10 for the foam. The windows have a low .20s U-factor and a SHGC of .26. Most of the windows face East with a few facing West and North. There is only one small South facing window. We will be using an ERV for ventilation.

In Mechanicals | Asked By Michael Grundvig | Apr 22 18
2 Answers

Crawl space: To vent or not to vent?

Building here in Chattanooga (CZ-4), there is possiblity of a basement due to shallow soil before bedrock. And we're on a slope, so crawlspace it is.

I've been preparing myself for a conditioned crawlspace but have run across info from 475 that is making me question. If the underside of batt insulation is sealed with a product like one of their Solitex Mento products, airtight yet vapor open, would this be an alternative to sealing the entire space? Thoughts?

In General questions | Asked By Ytsehoos | Apr 23 18
1 Answer

Summer water heating solution

Looking for a summer water heating solution. I am considering an indirect heating solution with a electric back-up. An indirect is a great heating season solution but keeping the boiler on all summer is a waste. My fuel choices are electric or oil, no gas available. Anyone have experience with these? I know that the best solution is probably a HPWH and PV panels but I am not well situated for solar.

In Mechanicals | Asked By Jonathan Blaney | Apr 23 18
13 Answers

Rafter insulation - design

Hi all,

So am revisiting insulating my attic rafters. I am in Richmond Va and have a 2 year old roof. I debated spray foam (closed) but it is very expensive. So I am looking at doing a 1 inch air gap soffitt to ridge and using Roxul R30.
I will have to fur out my 2x8s for this to work.
My plan is as follows:
R-30 Roxul - allowed by my building inspector - 7.25" thick
Ripping a 2x4 in half - gives me 1.75" of depth for furring out the 2x8
To ensure the correct depth, rip some 2x4s to 1" high and 1/2" wide and nail them to the rafters along roof line.

In General questions | Asked By Joe Watson | Apr 8 18
1 Answer

Inadvertent vapor barrier?

I live in MN and have a 12'x16' porch addition that I'm about to insulate the vaulted ceiling. I'm calling the porch a 3-1/2 season porch since I'm installing electric base board heat which allows me to heat the room, but only when I intend to use the room, which may not be that often in the dead of winter. The scissor trusses are just 4/12 exterior pitch with a 2/12 vaulted ceiling and 7" heel height at the wall line, so not a lot of room to meet R value requirements here.

In Energy efficiency and durability | Asked By BobPv | Apr 22 18
1 Answer

Sloped ceiling insulation

I have a story and a half home that we are remodeling. We also added a garage with bonus rooms above. We are climate zone 6 in Gillette WY. We taped all OSB seams, are adding 2” of rockboard insulation with 3/4 rain screen and Lp smartside lap siding to the exterior and used ThermalBuck to fur out our windows. We will also be using Ecoseal Plus to air seal interior framing.

To the point:

In Energy efficiency and durability | Asked By user-7005570 | Apr 22 18
8 Answers

Slab on grade house and garage : can I pour the floors once the shell is up?

I currently have the footings frost walls (4'), and the sandy base filled in and tamped for the slab. The house is roughly 50'X30', 2 storey, and the floor joists can technically span 30' (24" deep trusses), but the plan has a "supporting" wall roughly in the middle of the width to keep the floor span at 15-17'.

The garage is 30'X40', with no supporting walls (wide open).

In GBA Pro help | Asked By Mai Tai | Apr 21 18
10 Answers

Small addition with helical pile foundation in Toronto Canada


I am an architect in Toronto. My client is a contractor who wants to build a small one storey addition using helical pile foundation instead of continuous foundation to save on cost.

The finished floor is raised above the grade by about 21".

My questions:

-Can I use chicken wire to support the fibreglass insulation in the floor joists as it would be difficult to finish the underside of the floor with plywood I think
-Do I need a air-barrier like tyvek under the fibreglass insulation

In Green building techniques | Asked By Lowell Lo | Apr 22 18
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