Spray foam

[bert670]

In a few weeks I’ll be beginning construction and turning our two car garage into a living room which will have a wood stove. The contractor we’re using uses spray foam insulation which will be used below the floors, walls and on the 12’ gable roof (room will be approx 360 sq ft). The room will be accessed through the existing doorway (door removed) from our kitchen, so the only opening to the rest of the house will only be that door. My concern is, the spray foam guy came yesterday for a walk through and in his words said “once I’m done you’ll be able to heat this place with a candle”. I was planning on having a Hearthstone Shelburne installed centered on a exterior wall. Does anyone have experience with the quality of spray foam, and should I consider going down a stove size? Or was his statement just part of his sales pitch.

Edit: Forgot to mention the rest of the house is a approx 1800 ft center hall colonial. So out new sq ft will be over 2,000

 

[begreen]

It's true that the new space will not need a lot of heat. The woodstove will overwhelm and overheat the small area on all but the coldest days unless a system for moving the heat is employed. This would be true with just conventional insulation, but the air-tight foam insulation will make it so that very little heat is needed. It would be better to put the wood stove in the main structure if that's where the heat is needed and just have a baseboard electric heater in the new space or maybe a mini-split.

 

[bert670]

Thank you for the input, this room is the room I was hoping to put it in, as no other room in the house would really be appropriate for a woodstove. We’ll have a mini split installed in the room, but was hoping to use the wood stove for the primary heat source for the room, burning during the coldest months 24/7. There will be a ceiling fan installed, and I’m willing to run a box fan or something similar to get airflow from the new room to the rest of the first floor. I wish there was another suitable location for the stove, but my preference was to put it in this room for the heat source, and also for the center piece of the room.

 

[begreen]

It will be like heating a well-insulated ice chest. 360 sq ft is smaller than some tiny houses.

 

[Bad LP]

Believe the spray foam guy re: match.

I hope he's using closed cell foam.

 

[Tar12]

It was no sales pitch! My sons home is 3400 sq. ft....spray foamed throughout...interior as well as exterior walls and floor joists...his worst winter bill for this place was $86 bucks with natural gas...it is amazing as to how little that furnace runs! I think I would look at a small cat stove and figure out a way to pull excess heat out of that room!

 

[bert670]

Thank you for the replies, I've been searching older threads and right now I'm leaning towards downgrading to the Craftbury and having the HVAC contractor install a Panasonic Whisper vent on the ceiling and venting into the next room (a lont with using a fan if needed). The rest of the house was built in 1965 with 'ok' windows. We run on oil, and the only heat source in the new room will be a electric mini split, so I'd ideally like to use that as minimally as possible. The room will have 2 large windows, and a large sliding glass door on the same wall, and then two smaller windows on the opposite wall. The house is north facing and the most sun it will get is in the mornings for a few hours.

 

[Rearscreen]

My previous house was a post and beam that I built myself. Radiant hydronic and a Hearthstone Mansfield. The walls were foam curtainwall, foam like the stuff you spray in a can, not styrofoam. Ants love it to make tunnels. The only advantage for me was that I could easily hear them munching away in the walls as the panels acted like a soundboard. Borax and sugar water (Terro) solved the problem, but it was a yearly 3 day exercise to constantly feed the workers so they could feed the Queen, in the wall. If I were to build again I would use Roxul as insulation.

 

[BCC_Burner]

Sounds like poor air sealing of the exterior was to blame and not the insulation itself. Also, they make a wide variety of spray foam insulation with different properties for different applications. The how or why isn't important at this point, but it sounds like you ended up with the wrong insulation for your application.

Most homes we see here have R-6 or R-9 continuous insulation (occasionally R-12, but framers hate sheeting a house with that stuff), then spray foam filling the wall cavities. Occasionally we'll see three part assemblies with insulated Zip sheathing, spray foam to half the stud cavity depth, then batts to fill out the wall. We take our energy code EXTREMELY seriously.

I was in a house recently that had a blower door test result of 1.15 AC/H, but it did have a whole-house oxygenation system, so it makes sense to build it as tight as possible.

 

[brenndatomu]

My previous house was a post and beam that I built myself. Radiant hydronic and a Hearthstone Mansfield. The walls were foam curtainwall, foam like the stuff you spray in a can, not styrofoam. Ants love it to make tunnels. The only advantage for me was that I could easily hear them munching away in the walls as the panels acted like a soundboard. Borax and sugar water (Terro) solved the problem, but it was a yearly 3 day exercise to constantly feed the workers so they could feed the Queen, in the wall. If I were to build again I would use Roxul as insulation.

No bugs...

Home | Airkrete - All Green Light Weight Cement Insulation!

The most environmentally safe, the only fireproof insulation on the planet, gives off zero noxious gases and odors, and is 100% pest and mold resistant!

www.airkrete.com

 

[clancey]

Now that makes sense to me why would't people have something that is bug free and non toxic as well as mold resistant and pest free. That Airkrete all green light weight cement insulation sounds wonderful to me..clancey

 

[brenndatomu]

Airkrete all green light weight cement insulation sounds wonderful to me..

Only downside is it costs a little more than spray foam....I paid $2500 to have walls spray foamed (that was a deal) and the Airkrete guy quoted me $4000...should have spent the extra $...

 

[unhdsm]

I heated 1800 sqft fiberglass insulated house with a Shelburne and it barely kept up. And if you go down in size you won't get overnight burns unless you go with a cat stove. I kind of think that as long as you can move air through the house you will be okay. You can always crack a window but you can't get more heat from a smaller stove.