Foam insulation - Making cabin from prebuilt shed

[Raised on a Deere]

Pondering in the interest of time to have a quality shed builder make me one of those 16x32' with the corner porch and swing kinda thing to use for a cabin on some land in KY so I can spend extended vacation times around a bunch of kids and grand kids in the neighborhood. I live in Alabama.

These sheds are very sturdily built with strong roofs with hurricane plates to the rafters etc. I will place it on 5 concrete footings running crosswise to the building and anchor it down for a blizzard. The builder will work with me to have the insulation in the floor as they build, and then I will have walls blown with open cell after on site and plumbed and wired.

My plan is to have 6" closed cell in the floor and regular open cell in stud walls including 6" in ceiling then dry wall it all in. All this can happen by me making phone calls andwriting checks except for plumbing and wiring of course. I can do the rest while I am camping in it including do the HVAC and septic work.

It seems to me with a heat pump this thing would be pretty cozy and easy to heat, understanding that I have to build in some air exchange for such a tight structure.

Any suggestions or no's from your experiences or stories heard? Old wives tales are also to be enjoyed.:laughing:

 

[adventure bob]

My house is sprayed with 6" closed cell and a flash and fill in the attic. The only advice I would have is find an experienced sprayer. You can monkey this up pretty easily with guys who don't know what they're doing and you wont know for a while that they sprayed in voids, sprayed out of mix, or even gapped it. The equipment they use is critical to getting the mix right, and some cheaper guys either didn't pony up for good gear or don't maintain it very well. Are you going to do the ceiling? I'm assuming its just a ceiling, no attic space? That's were you make your money on warm conditioned space. You do have to think about air exchange; my house is extremely tight and we have to vent in the winter for moisture.

 

[Raised on a Deere]

My house is sprayed with 6" closed cell and a flash and fill in the attic. The only advice I would have is find an experienced sprayer. You can monkey this up pretty easily with guys who don't know what they're doing and you wont know for a while that they sprayed in voids, sprayed out of mix, or even gapped it. The equipment they use is critical to getting the mix right, and some cheaper guys either didn't pony up for good gear or don't maintain it very well. Are you going to do the ceiling? I'm assuming its just a ceiling, no attic space? That's were you make your money on warm conditioned space. You do have to think about air exchange; my house is extremely tight and we have to vent in the winter for moisture.

I am filling the 6" rafter space.

I think the biggest un ease I have is concerning the necessity of closed cell foam in the jointed floor. The cabin will be just a few inches off the ground they is built up a few inches higher than surrounding to insure above all water. Would this work with open cell if I tarpaper under the finish flooring? Do mice mess with the insulation etc

 

[AGRIMAN]

I am filling the 6" rafter space.

I think the biggest un ease I have is concerning the necessity of closed cell foam in the jointed floor. The cabin will be just a few inches off the ground they is built up a few inches higher than surrounding to insure above all water. Would this work with open cell if I tarpaper under the finish flooring? Do mice mess with the insulation etc

You will be fine with the open cell in the walls and roof, but I would not use/recommend open cell under the floor/crawl space. I would go with your original plan on using closed cell.

As far as mice, I have never seen them nest in foam, but I have seen the chew through it.

 

[adventure bob]

Id definitely suggest a vapor barrier to the outside (floor side) for either type of foam just to keep condensation off your foam. While its pretty impervious, mold will grow on it if it stays wet. I live in Colorado so water and moisture are only a concern on the human side of the foam.

 

[ustmd]

You will be fine with the open cell in the walls and roof, but I would not use/recommend open cell under the floor/crawl space. I would go with your original plan on using closed cell.

As far as mice, I have never seen them nest in foam, but I have seen the chew through it.

Mice will nest in open cell, but not closed cell

 

[adventure bob]

When they shot our house we opted for the fire retardant spray (the purple colored stuff) over the top of the foam, which in addition to adding fire retardant, makes it very un-tasty to mice and other beasties to burrow in.

 

[AGRIMAN]

Mice will nest in open cell, but not closed cell

I'm wouldn't be surprised. I just haven't seen it for myself yet. My son and I are spray foam contractors.

 

[Ed of all trades]

My shop is a shed like you say. The insulation under the floor is just held up by plastic draped over the flooring joists and will be a problem in the future. Check with your builder to make sure he is not thinking of doing it that way. Ed

 

[Raised on a Deere]

Thanks to all on confirmation of closed cell properties being desirable in floor exposed to outside. Also I am going to do my homework with respect to quality contractors and I like the fire retardant idea to ****** mice. My sister had a place that she left vacant for one one winter. When she came during the summer she found a colony of mice. Messed up a lot of stuff.