Saturday, December 13, 2008

Insulating without rewiring?

My house has no insulation. It is on the large size. Thus, I dread my upcoming gas bills.

I've been installing weatherstripping on the frames of the storm windows and will do the same with the windows themselves, if we have a warm day anytime soon. I've come to realize as I weatherstrip the windows that more cold air seems to be coming in from around the edges of the windows, presumably due to a lack of insulation around the window frame. Given that the exterior of the house is brick and that that there isn't any trim around the windows (just a nice rounded plaster edge), I have to imagine that gaining access to the framing around the window won't be easy.

My bigger question, though, is about insulating the house as a whole. I'd like to be able to blow in insulation, but everything I've read seems to indicate that you cannot blow in insulation where knob and tube wiring is present.

The wiring, while knob and tube, is in excellent condition. Every fixture I've removed is in a box, and on all of them, the insulation is in good condition. The current electrical service meets our needs without any trouble. As a result, I don't feel a strong desire to rewire.

I welcome any thoughts, ideas, and insights on the subject.


artemis said...

We had/have the same dilemma (though lesser consequences, since it doesn't drop below the 30s where we are!) Some people told us it was fine if the K&T was in good shape, and others said never never never. A further complication was that our insurance company wasn't down with it, since it's against code in some areas (though not here). Actually they really weren't down with K&T period; we were required to replace most of it, and our auto insurer refused to insure the house at all because of it.

The main fire hazard seems to be when the wiring has been upgraded at some point to use higher-capacity fuses or romex, etc.---then the original K&T wire insulation can fray, and if you then insulate over it, it has something combustible to ignite. So if yours is still all original and in good shape, it may well be much safer than if it's been fiddled with. We ultimately decided not to do it because we do plan to upgrade the wiring in the walls soonish (already did all the outlets and panel), and it's really only a winter heat issue here. I'd get a good electrician with K&T experience out to do a thorough inspection of all your circuits---where they go, what kind of shape they're in. If they get a clean bill of health, you can probably insulate somewhat without too many problems, but go by the electrician's advice on where and what type of insulation to use. You may also have walls without electrical in them so those are easy to do once you confirm it. Hope that helps---I imagine someone with actual electrical knowledge will also weigh in! ;)

Anonymous said...

We also thought our K&T wiring was fine. Last year my husband decided to rewire our old victorian. We are both very happy we did it since we found some not so great splice jobs inside many walls. We also had over 2/3 of the wiring in our home on only 2 circuits. It seems that when they added things over the years that they just "hooked" into something else. We both sleep better knowing that we have new wiring now. Good luck.

Todd said...

I hate to say it but you wouldn't be doing yourself and your family any favors insulating the wall cavities with K&T wiring. I'd say tackle one room at a time if you can't afford to do it all. Meet with some electricians and come up with a plan that allows you to re-wire one room at a time. You can rewire the room and insulate it at the same time.

Best of luck.

Mary Beth said...

I'd also strongly recommend against blow-in with K&T, just because there are surprises in your walls. You just haven't found any yet, which is why they're surprises (hee hee)!

This might be heresy, but... you may not need to insulate your walls. The traditional building materials your house still has (brick, plaster) have better insulating properties themselves than modern ones do. Even on new houses, wall insulation is one of the last items on the "effective ways to improve your energy efficiency" list. Attic insulation is worth more; weather stripping is definitely the most bang-for-the-buck.

Re: air infiltration at the edges of windows. Can you caulk there? It's obviously solving a different problem than insulation, but that should help. And you can probably do this now, despite the cold. (I've done interior caulk on window frames in the winter and they set up fine.)

Christopher Busta-Peck said...

Mary Beth - I like the sounds of that very much.

I hadn't even thought about caulking around the windows - that would definitely help, especially around the frames of the storms.

I think, of course, that many of the problems will just have to wait until spring when I can work on the windows without freezing.

Mary Beth said...

Ah yes, the "hey, we've found this problem now that it's cold/raining/whatever, but can't do anything about it until it's warm/dry/anti-whatever" scenario. How well I know this.

There is removable/peel-away caulk that you could use to seal the interior storms in place temporarily, in addition to the "permanent" caulking around the windows themselves.

I have, perhaps, an unhealthy obsession with the usefulness of caulk in the older home.

Oh! Another thought, if you're just worried about the framing in the walls near windows... What about a low expansion foam? Locate (or make) a small hole, insert nozzle, squeeze, patch later, and you're good to go. It's unlikely that you'd have electrical wires within the framing around the windows themselves, so that might meet your immediate concern while you ponder larger insulation decisions. We've used this around several doors that were poorly installed with great success (took off the casings, put expanding foam into the spaces between the framing, reapplied casings and caulked).

Christopher Busta-Peck said...

I really like the idea of spraying low expansion foam into the window cavities. I'm somewhat curious to determine how the windows are framed - with the exception of the dining room, the only wood trim that they have is the sill. The plaster is nicely rounded on the sides, with a bit more of a right angle at the top.

It'll be a little while before I'm allowed to do that. I've, um, been cut off from starting new projects until I finish certain things, namely, the wallpaper paste removal on the stairs and the vinyl flooring removal in the front hall. Yeah.

You should come by some time and see what we're up to - it's a fun house with lots of potential for caulking - there are even windows in the attic with ice on the inside!

Mary Beth said...

Please, please, please tell me how she managed to reign you in until you finish the projects currently in process. This is a technique I simply MUST KNOW. LOL

Ice-covered windows? How "charming"! At least you know you don't have overly-dry air in your house :)

Christopher Busta-Peck said...

In every relationship, there are certain lines that cannot be crossed, and certain threats that accompany them. I think this one involved either her moving back in with her parents or making me take care of Everett all evening long. Either that or the threat of no longer doing my Home Depot runs for me, which add an hour, at the bare minimum, to my drive home.

Mary Beth said...

*considers the unfinished projects list*

... mind if I borrow Everett for an evening?


Christopher Busta-Peck said...

His time is pretty expensive, you know. An evening of his time is worth at least a couple days labor on Chez Bustafeltz.