Exterior foundation insulation question

[HoosierBuddy]

Hey guys.

Sorry for a sort of off-topic question...but I'm not sure what to do.

My house has a bumpout breakfast nook, about 12' X 12, with 2 exterior walls. The floor is always super cold in the winter. The room is built over a VERY low crawl space that has vitrually no access to it. Even if you could get access, there would only be about 8" of access...the distance between the bottom of the floor joists and the concrete slab that covers the house's old (no longer used) cistern.

Now...the rest of the house is over an unfinished basement, which I insulated with a vapor barrier and 2" polystyrene and it made a BIG difference in my heating bills. Since I can't get to the inside of the crawl (without a jackhammer)...I was thinking about excavating a trench around the crawl space, wrapping it with a vapor barrier and installing polystyrene up to the bottom of the siding. I have 2 questions though:

1. How can I protect the polystyrene from getting hammered by the weedeater?

2. How can I protect against carpenter ants or even termites using the polystyrene for nesting?

Ohhh...BTW the water lines for my garage run through this crawl...so it's garage related. Well...maybe not....but any help or advice would be very much appreciated!

Phil

 

[jklingel]

Check at dow.com. They have some termite-resistant foam board, and some stuff that has a tough outer shell on it. Those may do you.

 

[JMURiz]

I saw a product in this month's Family Handyman Magazine, it is a rigid foam insulation panel that looks like stucco etc. Not sure if that'd help but it might.

Why not just insulate the under-side of the floor (under the crawlspace)? My dad did that under a room addition at my sister's place and it helped a lot. Just used regular batts and held them in place with straps.

 

[partsman]

you could also try capping it with some alum.
you could also try talking to a local pest control they have some very good products to control the pests

 

[locoman]

Take a look at styro tuff II. Worked great for me. I used it on a stem wall. I have 8 inches underground and 24 inches above. I used 5/8ths p2000 that give an R-19 insulation. I coated the bottom edge before I applied the foam to the wall for a good seal.

 

[Junkman]

Since there is only about 8" between the joists and the concrete, have you considered having a spray in place insulation contractor filling the entire cavity with spray foam. I think that would solve the problem for you. It would keep the pipes warm, and would eliminate any cold from the floor. The only down side that I can see is if you ever had to jack hammer the floor out, you would have to remove the foam first. Spray in place foam is also dense enough to discourage any problems with pests.

 

[HoosierBuddy]

I have considered that. I'm scared of the cost, and there are no local installers.

Since posting this, I found 1" polystyrene with a stucco-like finish on it at menards, and installed that. This morning it was 19 degrees outside, and the floor was still cold as hell.

I wonder if TigerFoam or any of the do-it-yourself foam products could be used? It would take about 216 cubic feet to fill. It would also require a 12 to 15 foot long wand to shoot it in there. Heck...if I had that I might be able to just get it to pile up along the exterior walls and need a lot less.

I wonder if I could make an application tool out of rigid tubing?

Phil

 

[CmbtApl]

I don't know if this is too late for you or not.... Conproco makes a product called structural skin (http://www.conproco.com/StructuralSkin.htm )that is applied over the rigid foam insulation to prevent weedwacker divots and bugs, etc. The stuff comes in bags and is mixed with an admix K-88 (1 gal) and water (~1 qt) in a cement mixer. The mixed material looks like concrete and is applied directly to the foam insulation like stucco about 1/8" thick. Each bag covers about 50 sq ft. I have used it on a couple of houses and it sets up hard like concrete and looks like concrete. It is really very durable. Be sure to clean out the mixer between each batch because it attaches to the walls of the mixer and is VERY hard to clean off.