crawl space perimeter insulation
My 160 year old house (upstate NY) has a stone foundation (duh), half basement and half crawl space. A previous owner covered the entire exterior perimeter of the foundation with plywood over fiberglass. I’ve started removing that shell (the fiberglass is almost entirely gone and the plywood is rotting). I had intended to touch up the stones with some mortar, then try and insulate from inside. What I’m finding, though, is that (a) some of the foundation was replaced with block somewhere along the line and (b) much of the stone is not nearly as nice looking as I had though it would be. So I’m now debating whether to (a) parge the exterior with a layer of concrete/acrylic mix and try to insulate inside, (b) follow the previous plan and put in a skirt of treated plywood over some rigid foam, paint the plywood, and forget about it, or (c) sell the damn place, buy a condo, and play more golf.
I’m really not sure how I would go about insulating the inside of the wall. Access is tough, and the walls are composed of stones of widely varying width. But I like that this approach would leave me with a more authentic looking exterior. I’ve read some suggestions (pro and con) about spraying foam insulation on the walls, but out here in the boonies I don’t know anyone who knows anything about this procedure (though I’d be happy to try and teach them if it was worth the effort). I’d appreciate hearing some thoughts on these options, or suggestions for other approaches. I don’t want to insulate the floor joists, and I don’t want to ventilate the crawl space (which is bone dry anyway).
Replies
Hi Birdsmouth,
I've got a 175 yr old house I own in Upstate New York I could let go real cheap...I moved to Minneapolis and am doing apartment living and playing more golf ;-)
Just out of curiosity, what part of Upstate? My house is near Cooperstown.
I've wrestled with the same problem with my house except that the foundation looks good, there fore I definately want to approach it from the inside. If I had better access to the crawlspace, and if I had less things hanging down below the joists, and less posts and such, I would have covered the bottoms of the joists with foil-faced foam and taped the seams. But those "ifs" kill that approach. I've thought of building a really minimal 2x4 wall around the inner perimeter with treated lumber and covering that with foil-faced foam, but the walls are pretty thick, and that would leave my hot water baseboard piping on the cold side of the wall.
So far I've done nothing...not much help, I know, but just a couple thoughts from a fellow in same boat.
Steve
Steve
I'm near Ithaca, and I am not in the market for another old house at any price. This is my last rehab.
Sounds like we've done a lot of the same kind of thinking on that crawl space issue. There are moments when I, too, talk myself into thinking that insulating the floor above the crawl space is not such a bad idea. I've got some plumbing and baseboard heat piping running through there, so I need to keep the space moderately warmed, but it is open to the basement through a couple of good sized holes, so there's probably enough heat escaping from the boiler and indirect water heater to prevent freezing. Somehow I keep talking myself out of that approach, though.
Jeff
PS There are better places for golf than Minneapolis, you know.
Hi Jeff,
Ithaca is nice. And you might even get some equity out of your house in the long run, unlike where I lived. Money down a rathole...
Minneapolis is where I grew up. Spent the last 20 years in various spots on the east coast. I'm here not for the golf per se, but because the wife got a fellowship to go to business school for free here. The golf is good enough for a hacker like me. I have yet to break 100...
I too have holes you could drive a truck through between the crawl space and the cellar. I would think sealing the perimeter would be the way to go if you can figure out a way. Spray foam sounds good if you could find someone. Perimeter would be a lot less area than the flooring (in my case anyway).
Steve
c) sounds good to me!
But if you want keep paying taxes in NY I would suggest that you definitely patch, repoint anything inside and out that is structural. Then parge outside and seal against water.
Now you are ready for insulation. I've seen several places with these irregular rubble stone walls where they had urethene foam sprayed to the inside. Insulates well, looks like hell, modest waterproofing, though from inside. Not cheap but in my mind the best way to go to eliminate drafts.
Thanks, Piffin. I'm pretty convinced we're in agreement up to the insulation part. But I don't know anyone in my area who handles the urethane foam, nor anyone who's had it done, so it's hard to focus on that solution. Also, I'm not sure that an expensive option is really worth the effort in reduced heating bills. Think I'll do some parging this week. I've done this quite successfully on block before, but I think it's going to be a bit of a headache getting a relatively smooth finish with my parge mix on those irregular stones. Life's an adventure.
jeff
Considering what you get for what you have to put into it, I'd think sprayed foam would be the optimal solution. You can't access the stone for work later, but then, who'd want to? You'll find several sources for foam re' Fine Homebuilding's ads, usually a propane tank type container with a hose and spray head. Not real cheap, but works great once you get started, and permanent, unlike fiberglass and wood. Time invested: minimum. It's DIY, since the labor is minimal, once you get down there.
I can refer you to some possible sources, if you can't find any.
It hadn't occurred to me that this was a job I could do myself. Just checked through the current FHB and found only one relevant ad, for polyurethane foam spray, and their Web site says
"Required equipment elements include a plural component proportioner pump with heaters, dual high pressure heated hoses, high pressure mixing and spray gun, and feed pumps and hoses. In addition, an air compressor and electrical generator may be needed."
That's not the kind of stuff I keep in my toolbox. But maybe I'll do a little more research.
jeff