Blown in wall insulation?

Question

I have a 1948 Colonial in central Pennsylvania. Last winter was miserable and expensive. It cost 500 a month in oil just to keep the house at 64. I replaced the 20 yr old oil furnace with a brand new gas furnace. I'm thinking about blowing in fiber cellulose insulation into the exterior walls to keep my heating costs low I'm certain the house has no wall insulation. Has anyone had any negative or positive results from this. I don't want to waste my time. I figure it would cost a little less than 500 to do the whole house (1800 sf). My other option is to wait 2 years for when I replace the aluminum siding with vinyl and have spray foam injected into the exterior walls from the outside. Unfortunately, I have plaster walls, so its not as easy as tearing down drywall and putting up batts. Any advice/recommendations.

Answer 1

right on Honey... although my cellulous insulation has kept "fluffy" as i check from the open cavities in my attic. I wouldn't use that only because of your allergies. It is a dirty nasty mess when you do that project and if you do it from the inside, if you don't clean your ducts afterward and everything else, your body will be aggrivated by dust for a LONG time. Hold out and bat it up when you side it.

Answer 2

Blow-in insulation is installed by drilling holes in the interior wall plaster, usually two per stud bay as there may be fire blocking half way up. These holes will have to be patched and the wall re-painted or at least touched up. I've found that upgrading windows yeilds a greater effect.  

Answer 3

Any insulation you get in those walls is better than nothing. I would use rock wool or fiberglass blown in rather than an formaldehyde based foam. I've heard bad things about toxic vapors with formaldehyde based products.

Answer 4

Blown in insulation works fairly well in attics (if you later go in and manually unplug the air vents).  It works much less well in walls because over a relatively short period of time it packs down and leaves you with no insulation on top, and ineffective, tightly packed insulation on the bottom. (It is actually the trapped air in fluffy insulation that makes the insulation effective.)

With the way heating costs are going, you might be best to "bite the bullet" and borrow the money to reinsulate and reside properly now.  Since your walls are probably 2 x 4 construction, you might also seriously consider adding 2" of closed cell styrofoam insulation to the outside walls under the new siding.  Siding manufacturers make moldings especially for this purpose to finish around windows and doors.

If that's not an option -- or even if it is -- there are a number of cheaper things you can do to make a big difference in the amount of heat you need.  Invest $5.00 in a good caulking gun and another $40 or so in a dozen tubes of good caulking.  Then go around the exterior of your house and caulk every crack, hole and slit.  Be fanatical.  The smallest holes add up to big holes that let your expensive heat escape.  Go into your basement and carefully inspect it for any possible air leaks.  Plug and caulk every suspect.

Replace the weather stripping around all your doors and be sure that it's making good contact.  On a sunny day, critically inspect the crack around each door.  If you see any light at all, you're seeing where your money goes out in winter.

On a breezy day, make a "leak detector".   Cut a 1" x 24" strip of tissue paper and hang it over a clothes hanger.  Hold it up as you slowly walk about your house, pausing here and there.  It shouldn't move when you stand still.  You may be surprised to find that it does.  Hold it near windows and doors.  If it moves, you've found a place where you're losing heat in the winter time.

Do you have double-glazed windows?  If not, seriously consider using "shrink wrap" storms this winter.  This stuff looks a bit like SaranWrap and comes in all sizes.  It goes on over the inside of your window with tape.  Then you shrink it taut with a hair dryer.  We used it some years ago during a  - 40 Canadian winter in an old mobile.  It made an incredible difference.

Oh, another thing.  Don't be shy about using that blown in fiberglass in your attic.  Many western Canadian homes now use a 16" to 20" layer in the attic and to good effect.  Even if you're losing heat from the walls, at least you can drastically reduce the heat loss from the big ceiling areas.

If you do choose to insulate your attic, another way you can help increase the comfort level in your home is with ceiling fans -- yes the big overhead fans people use in summer.  Reverse the fan so that it pushes room air up toward the ceiling.  This forces the warm air that tends to gather at the ceiling outward toward the walls.  The warmer air then flows down the walls forming a "blanket" against those cold walls so that you won't feel their chill as much.

In the evening when you're sitting reading or watching television, an electric heating pad placed on a folded towel on your footstool or on the floor under your feet makes the whole house feel warmer.  These devices are cheap and use very little power.

I really hope these little ideas help you as much as they've helped me over the years.