Floor/crawlspace insulation

[Dan Hartung]

Problem: The kitchen is partly over the basement, but also partly in a wing that includes the garage. The carpeted floor between the outside wall and the point where the basement starts gets *very* cold in winter. As a crawlspace there isn't much: 2' perhaps, probably closer to 18". I have no idea at this point what is under there; the kitchen was built in the 1970s, but the home dates to 1858.

The carpet needs replacement, badly, and an obvious choice is some sort of vinyl/laminate.

My question is, are there practical options for insulating *under* the vinyl flooring? There's already a step up to the kitchen on one side, and a high threshold wouldn't be out of imagination at the other door. But perhaps this is a crazy idea. Foamcore-type material would certainly compress over time and I know that would limit its insulating properties.

If we really had to, and it may be advisable anyway, getting into the crawlspace while the carpet is up is an option. (No removing kitchen cabinetry though, so we can't just rip up all the flooring!)

What should I think about in terms of insulating under there, given that access is such a problem? A vapor barrier is probably code today, right?

[Joseph Meehan]

First step would be to find what is under there. Find some skinny local teenager to take a look. You may even be able to get him to do the job. You will want to find out not only about the insulation that is not there, but also the condition of the wood that is there. If it is damp due to poor ventilation, you may have a bigger problem than you think.

I would not want to work in that limited space. Another option, and NOW is the time to do it before you put down a new floor. is to take up the subfloor, inspect, repair as needed and insulate properly.

The idea of using sleepers to gain room for insulation is not going to wear well in the future. I think you will be sorry you did not do it right.

[David Babcock]

In some of the rehabs I have done on older homes sitting on grade or with a small crawl space such as yours I have had to pull up some of the subfloor to look at realized framing and rot issues. This would also give you the chance to do any insulation you might need. If you have to replace any structural joist or beams remember the word structural and get a professional opinion. But not knowing what type of heating you have, if you have forced hot water I might think about forgoing all the insulation ideas and add a heating system to heat the floor. Something to think about.....eh?

Dave

[Dan Hartung]

Heh. I have a skinny nephew, but he's an ADHD kid, not too dependable on the project front.

I suppose. We've never had a major moisture problem in the basement. In this 19th century house there are of course all sorts of wood elements that might give one pause and short of a major obvious problem like sponginess (which we don't have) I'm not sure what I'd consider worth doing.

At the end of this crawlspace, that used to be the outside cellar door we sealed up, you can see what may be a clue to the technique used in the inaccessible area. There's a minor furring-type strip tacked to the bottom of the joists, vaguely supporting fiberglass batts with raggedy reflective barriers. (The one section between the outermost joist and the wall has some sort of firm foam rather than a batt for no obvious reason.)

That's basically my thinking. Vapor barrier, new insulation, perhaps a vent? I should probably look up the code.

I did wonder about digging out a trench to extend under the cabinet area but I'm not sure how well filling it in and installing the vapor barrier would go. Another option, I suppose, is to just take out as much dirt overall as is needed to allow crawling underneath. (Yech either way, of course, and it would have to come out through the kitchen, double yech. On the positive side I could live out my Great Escape fantasies.)

True, I'd rather do it right, but doing it really right might be next to impossible. There's so much with this restoration that could still be "redone right".

[AJScott]

Hi, guys. My eyes kinda glazed over a little while back, so perhaps an interested party can translate for me: Is this merely a case of someone wanting a cold floor to be less cold when they put in a new, laminate flooring if I recall right, or is the problem/desired result a bit deeper than that?

AJS

[David Babcock]

Having been through this any number of times, anytime you look for trouble in an old house, you will find it. If in fact there are no problems suspected or known, and all you want is a warm floor, then go with an under floor heating system if you have forced hot water. With forced air, it's another thing entirely.

Dave

[Dan Hartung]

Well, the basic problem is a cold floor. When I started thinking about that I realized it is "deeper", and this is the time to solve it.

[AJScott]

Dan:

I can sympathize with your wanting to get to the ultimate root of the problem and solving it. That's usually the best route -- but not always the most practical or reasonably decent on the wallet. If I was in your position, and if your cold-floor problem doesn;t seem to be caused by something that will cause you other problems down the line (i.e. moisture/cold leaking in big time from holes in the wall, etc., that could cause damage to the "exposed" space beneath the house over the long haul), might I suggest this relatively inexpensive fix that has eliminated ALL of the cold-floor problems in my basement (as well as provided the solution to my basment's chronic seepage problem).

Menards stocks these 2' x 2' Dri-Cor panels that might just be the ticket. They're the really nice tongue and groove chipboard panels that fit togethr like a dream and have an inverted-waffle sheet of plastic mounted to the underside that, all in all, raises everything about 3/4" off the primary surface floor. I'm not kidding you -- when I put these panels down, there's at least a 5-8 degree difference between the new subfloor and the original main floor. And you can then put a laminate floor or carpeting over them just like any wood subfloor. Matter of fact, I had a few people tell me they'd look great on their own without any additional cover --altho I personally wouldn't be that charitable about the issue.

The only drawback is, they run about $4.80 per panel. But IMO as far as my own experience with these things, it's money well friggin' spent.

I was kinda skeptical about these panels, but I bought 2 of them, laid 'em on the floor and stood barefoot with one foot on the concrete floor and one foot on the panels. MAJOR difference.

Check it out for yourself and see.

AJS

[Dan Hartung]

No magic here, just thinking "when else will we have this opportunity?"

Since this is the only living-space-over-crawlspace in the house, it seems worthwhile to think ahead a little. I still feel like getting a vapor barrier in there somewhere is a Really Good Idea.

I think that's a great idea, in line with my lightbulb. I still don't think I'm going to be able to insulate the underfloor very well (any better, that is) with the limited access we'll have.

Hmm, we could do the whole room with about 16 or so. Not that bad really.

Thanks!