Proper Wall Insulation for Old Home
Pnut
| Posted in Energy, Heating & Insulation on
The upstairs section of my 120 year old home is being gutted…before putting up drywall, I wanted to insulate the walls while I had a chance…(attic will be done shorthly). The house has been drafty with the upstairs being quite cold in the winter…Replacing the crappy 1970’s windows will help, but I wanted to do all I can, now that the walls are open to make the house tighter and more energy efficient.
The walls are balloon framing with real 2X4. The sheathing is 7/8 inch redwood 1X6 with 7/8 inch siding on top of that.
What are your insulating recommendations? Thanks in advance…
Replies
I've been pretty impressed with the performance of my old house after insulating using dense-packed cellulose insulation. You'll need your drywall on to do this process (or a special kind of scrim), which has a short learning curve. If you buy your insulation at one of the box stores like HD or Lowe's, the use of the blower is included with a minimum purchase. You can also hire it done, of course.
The blown cellulose works great for getting into the small spaces, which are more of a pain to fit with fiberglass; this helps to eliminate moisture traveling through your walls and contributing to rot and mold. If i hadn't wanted to keep my plaster walls intact, i would also have used a layer of foam insulation on the inside face before the drywall as a thermal break as well; you might be able to do this, depending on whether the extra depth messes with trim profiles. The board sheathing on my house was shot and 7/16 OSB was only $5/sheet at the time, so i resheathed in order to not have cellulose squirting out the cracks and knotholes, and filled from the outside. Another point is that you may be able to insulate the first floor by poking the delivery hole down the bay. The cellulose is treated with fire retardant; fire being a concern with balloon framing, this may be a further benefit.
If you've a lot more $$$ to spend and don't want to DIY this, you can have the stud bays sprayed with foam insulation, which also seals all the weird shapes old houses have and will sturdy up your board-sheathed walls. There are two main types of this insulation and some people are concerned with its off-gassing when installed or during a house fire. There is also a wet-sprayed cellulose installation which is rather more environmentally friendly and great fun to watch being installed. Both of these processes are done with the bays open.
Wow, Splinter...Thanks for the reply...Alot of good information!
Here is some additional info to chew on.
PLEASE, PLEASE, PLEASE.
Just paste the URL into your message.
DON'T UPLOAD THEM!!!!
BIBS (Blown In Blanket System) by Johns Manville. I'm pretty sure they are licensed franchises so you might have to look around to find the company in your area that sprays it (and you'll hear a lot of disparaging things from people who don't).
Best insulation I've seen for remodelling with all the oddball and extra framing members, wiring and plumbing - fabulous stuff. And they blow it before you rock the walls so you KNOW what got insulated and what didn't.
Check it out, best thing I've seen in a long time, right up there with fiber cement siding and architectural comp roofing.
One thing you should consider. If the house is balloon framed I bet the siding is not back primed. If you insulate without back priming the old exterior wood the paint will peel off. Insulate however you deem appropriate, just be sure to prime/paint the exterior wood that is exposed to the inside when you strip the interior walls.
Well I actually thought of this, but here's the situation....
There is 7/8" X 6" board sheathing, then covered with 7/8" siding (both are redwood)....I can't get to the back of the siding without a complete tear-off. I CAN, however paint the back of the "sheathing." Would this be worthwhile, or a waste of time/money???
Thanks again to everyone for the thoughts/ideas.
Well, here's the real gen.
I did the same last year. Took one of the rooms down to the studs and redid it.
First, get the book from Taunton on Weatherising and Insulating. It tells you about where drafts start and hoe to kill them.
I plugged between the joists with ridgid insulation except where there was knob and tube (nothing wrong with it) and that, I covered with 3/8 plywood and blocked the end, past the K&T, and foamed everywhere. Put R40 into the ceiling, R14 rock wool into the exterior wall and built up the pony wall to get it into R28.
Added a skylight for no other reason that he deserved it.
The area is really much nicer.
Quality repairs for your home.
Aaron the Handyman
Vancouver, Canada