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18 Answers

How to fix my unvented cathedral ceiling roof assembly?

We tried to build a house with a fairly tight envelope based on reading I could find. Well, apparently I messed up, so really want some advise before I mess things up more.
House is in central Missouri( zone 4, but real close to 5). Small, 750 sf but with an open loft making it about 940sf. Sealed Concrete slab as the finished floor, and new construction ( under roof in may but moved in The next January). Red metal roof and one side of that faces north..
Walls are 2x4 and we used open cell foam with 1/4" foam inside the studs as an air ( not vapor) barrier.

In General questions | Asked By Brenda K | Feb 16 17
4 Answers

Dense packing cellulose with the Krendl 425

Hi All,

I am going to attempt to dense pack several horizontal stud bays (2x10 floor joists, 12in o.c., between attached garage and bonus room) using the Krendl 425 (14amp 2-stage blower, pushing 1100 – 1400 lbs of cellulose per hour) over the upcoming weekend.

In Energy efficiency and durability | Asked By Joe Duchek | May 23 17
13 Answers

Can I combine floor and wall heating in a solar passive house to avoid overheating?

I have consulted many "experts" on highly insulated houses, most of them recommend to use ductless heat pumps to heat the house. But I am a radiant heat addict...
Apparently the problem with radiant floor and passive solar is that when the sun comes out, the southern side of the house is too hot because the concrete slab has heated during the night and is warm and when the sun comes out it can bring it to a much higher temperature.

In Mechanicals | Asked By Micheline Freyssonnet | May 22 17
7 Answers

Building new home in Delaware and using insulated Zip exterior sheathing

Addressing the stud cavities, should I tape or caulk zip insulation to studs or is the compressed sheathing insulation to stub enough.

In Energy efficiency and durability | Asked By Edward Serafin | May 24 17
6 Answers

Slab on grade and wet room floor question

I am working on a "Tiny House"-type structure (12 x 16) that will have what seems to be referred to as a "Wet Room" for a bathroom in which the shower can use the entire room. This will allow me to keep the bathroom's footprint low. Anyhow, the floor of the space will be a slab on grade and the floor drain in the wet room will of course be pitched correctly. I do plan on insulating under and around the slab floor but I may acutally use furring strips to put in a floating engineered (wood or cork) floor for the living and kitchen space for a more comfortable surface.

In Green building techniques | Asked By John Brown | May 25 17
3 Answers

Should I do a birdsmouth cut for low sloped (tiny house) shed roof?


We're getting close to framing my roof for my tiny house on wheels. The roof is a low sloped 2:12 pitch. There will only be 3-6 inch eave/overhang.

Should I do a birdsmouth cut for this? What benefits does this provide? If not, what method do you recommend that I do and why?


In Green building techniques | Asked By Grey Wolf | May 25 17
2 Answers

New home in DE

Plan to sheath with insulated ZIP 4x8 panels. In the interior looking at the 2x6 stud caviity should I caulk the Zip insulation to the stud or is there enough pressure from nails to seal same?



In Energy efficiency and durability | Asked By Edward Serafin | May 25 17
4 Answers

Calculating annual heating losses

I'm trying to determine cost effectiveness and payback periods for going with thicker insulation on the house I am planning. My project manager does not offer services of energy modeling, so I would like to do some of it myself. I will probably end up paying an architect for it, but I'd like to give it a go myself.

I calculated U-values for several walls, floors, roofs and windows. I have areas. I have heating degree hour value for my climate, which is ~78 000 (typical central europe). i have insulation prices.

It's extremely straightforward.

In Energy efficiency and durability | Asked By Davor Radman | May 24 17
9 Answers

Trane 38 SEER 15 HSPF minisplit

Anyone know anything about this, especially its output in low temps. Claims to provide heat down to -22F and cooling to 129F.


In Energy efficiency and durability | Asked By Venkat Y | May 24 17
3 Answers

Use foam board underneath fountain footer?

I am installing this fountain in PA:


I don't want to dig 36 inches to the frostline.

Can I dig 2 feet, put tamped 3/4 clean stone, place XPS foamboard and then pour concrete?

In Green building techniques | Asked By John Sean | May 22 17
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