Insulation in uninsulated old home

[Jeffrey Silverman]

I have a 1928 home that is not insulated. I keep seeing posts referring to "blowing in" insulation.

What is this? How can I do it? What tools do I need? Should I pay someone to do it?

thanks!!

[Bob]

referring

For the attic, they just feed insulation bales into a machine outside, which grinds them up and blows them through a large hose all over the attic. For walls, they drill holes into each stud space and blow it in through a tapering nozzle into the stud space. The holes may be from the inside or through the siding. If through the siding, they often then plugs them with plastic covers. The insulation is often "cellulose", which is basically ground up newspaper treated for fireproofing.

The basic machine for blowing cellulose into the attic is often provided free by the place you buy the insulation from. I don't know if they can provide the attachments to blow it through 1" holes in the walls. Call insulation contractors for estimates, which should cost you nothing.

My 1926 house had the walls done this way before I got it, and some, but not enough insulation blown into in the attic. I chose to cover that with fiberglass batts, which I can move easily if I need to work on anything in the attic.

Bob

[Tom Miller]

My (non-professional) experience is that insulating the attic of an old uninsulated home is always worth it and insulating the "rim joist" (runs around the top of the foundation) is helpful. Sealing up obvious air leaks in doors and windows with various insulating materials and caulk is effective. Storm windows are effective. Insulating the walls may or may not be cost-effective depending on the climate and the cost of installing the insulation.

We live in a 1921 house which had not a bit of insulation in 1981 when we bought it. We added insulation strategically after calling the local utility and getting a free site evaluation -- which was surprisingly thorough and informative.

It may be that blown in insulation will suit your needs. But I would do a little reading on insulation methods and insulation materials before running out and picking one method over another, because it depends on your house and climate. There are 1000s of books and pamphlets on this subject.

[SQLit]

I lived in an 1930's farm house in Iowa, Dad and I did the attic, he hired a contractor to blow the walls. I would do the same. Check new homes in your area and see how much they use in the attic. Use that as a guide.

[Bob]

|> My (non-professional) experience is that insulating the attic of an

joist"

obvious

materials and

walls

the cost

My experience on my previous house was that insulating the walls was WAY more cost effective than storm windows. The walls cost about 1/3 as much, but the effect was similar.

Bob

[Tom Baker]

I'd suggest a look at the Building Science Corporation web site. It might give you some background on insulation needs and methods for your climate. There are a lot of foam, cellulose, glass fiber insulations and it is well worth research. I used a "new" insulation a number of years ago. I opened a wall today as part of a project and found it had essentially disappeared.

Tom Baker

[j j]

go to home depot. they have this cellulose insulation that you blow in a space using a machine. thye rent the machine and might even give it free for a day with a minimum purchase.

if you have enough space between plaster and the wood behind, you can make holes in the plaster and blow the insulation in. it's certainly better than ripping out the walls completely.

[Walt Conner]

Just finished helping two sons blow insulation in each of their homes, one aluminum sided, other brick with plastered interior walls.

Walt Conner

[L. M. Rappaport]

On Wed, 10 Dec 2003 13:23:28 -0500, Jeffrey Silverman wrote (with possible editing):

Someone in another post mentioned that there is now a substitute for the old urea-formaldehyde insulation that was available in the 70's. It had a high R-value, around 5 as I recall, but it suffered from outgassing formaldehyde and some people couldn't tolerate that. The big advantage, however, was that not only did it not expand, but actually shrunk something like 1 %. If this new stuff doesn't outgas and the R-value is as high, it would be a lot better than blown cellulose which tends to settle in the walls. (fine for horizontal surfaces, however). You might look into it a bit. Sorry I don't have more information.

[Jim Elbrecht]

-snip-

How do you sell the shrinking as an advantage? The whole point of it was that it filled the wall cavity. The shrinking left spaces & voids, so your R-5 was suspended in the center of a cavity surrounded by cold air. It was also evidence of the gasses that the homeowners were breathing. The old foam insulation was a great example of something that would work very well in a lab, but in real life was a hit-or-miss proposition.

It was a couple years before anyone figured out that the old Urea Formaldehyde stuff was outgassing. I'd be slow to jump on a new bandwagon. [and wouldn't jump at all if there is a chemical reaction on-site that depends on temperature, humidity, or whatever other substances might be introduced to the mix inside a wall cavity]

Cellulose, properly installed will not settle in a wall cavity. It also has the advantage of fairly easy removal.

I insulated my house with cellulose-- then 10 years later I renovated & needed to take down the old lathe & plaster walls. In 10 years, there were only two runs that had settled at all. I removed about

500 square feet of cellulose easily with a shop vac. [and spread it out in my attic].

The things to remember with installing cellulose in the walls are- A. Inspect the cavity before you start to blow. [I remove a strip of siding 1/2 way up the outside and inspected up and down with a flashlight & mirror. Some 'pros' just use a snake to poke in the cavity to be sure there are no firestops.] B. Know how much cellulose it should take to fill that cavity-- if you 'fill' it too soon, you need to find what is blocking the flow. If you put 3 bags in one cavity, you need to go inside and clean up the mess.

Fun places in really old houses are where the walls reach the basement in balloon construction-- sometimes you need to plug that with batting.

Another spot where I've made an incredible mess was in a house that had built in dressers in the bedroom. The builder hadn't used any sheetrock behind the dresser. So after we used *way* too much cellulose in one cavity we went inside to inspect & found that we had nicely filled the homeowner's dresser with cellulose.

After that mishap we always checked behind cupboards & dressers to be sure there was some sheetrock.

Jim

[Phil Munro]

That made me laugh. Also, in our house, the ceiling cavities between

1st and 2nd floors were open into the walls.

[Childfree Scott]

Was it this:

Looks like I can do it myself. Good thing I haven't painted yet. High R value also (important when you only have 4 inches to work with). I also have an uninsulated home.

[Tom Miller]

You are right that insulating the walls will save money, cut down on drafts, make the house easier to heat, etc. I fully agree. But whether or not it is cost-effective in terms of your gas or oil bill depends on where you live and the type of house you have. Here in NJ, a relatively moderate climate, the payback on retrofitting walls with insulation in my three story brick house with plaster walls was multi-decades in 1982. I'd be dead or living elsewhere before payback. Insulating the attic was a different deal entirely -- highly cost effective.

The storm windows I was speaking of are for my (handsome) original

1920s wooden single-pane double-hung windows. I don't know if the storms are cost effective today or not, but I cannot imagine living with the incredible drafts that blow through without them. Fortunately for me, the house came with most of them already installed, and I added only a few and repaired about 8. The house has 18 windows on the first floor alone! Certainly other homes with different types of windows might fare better than mine without storm windows or replacement windows.

Anywayz, my point was that before spending on any kind of insulation project for an old house, a competent evaluation is called for. Making a blanket rule for all houses in all climates is risky. And as I say, I'm only speaking from personal experience. I did do a lot of reading on insulation however.

[Jeffrey Silverman]

Ballon framing questions: When did they stop using balloon framing? How can I tell if my house is framed that way?

My house was built in 1928. I live in Baltimore, MD.

Thanks.

[Jim Elbrecht]

-snip-

I don't think everyone has.

If you can get to a gable end in your attic, tie a heavy sinker on a piece of string and drop it down the wall. Measure how far down it goes. If it goes to the basement without obstruction, you have balloon framing. Check several spaces [you'll need to do every one before you insulate whether you use cellulose or foam] as sometimes a cross-brace, or some floor boards will obstruct a couple cavities.

In Baltimore you're insulating as much to keep summer heat out as to keep the winter heat in. With that in mind you should look closely at your options.

You need to be more concerned with getting some reflective insulation in your attic, and insuring that you have excellent ventilation up there. The money you spend on your attic might have a payback of a year or two. Your walls are going to take longer to reach the break-even point.

Jim

[Jim Elbrecht]

-snip-

Good point-- I'd forgotten that that is one reason I used to take off a strip of siding in the center of the wall. It allowed you to check up & down *and* across. We would put a batt of fiberglass in that cavity about an arm's length in. Then we'd fill the lower half, dropping the hose right down to within a few feet of the bottom and withdrawing it as we filled; spray a bit to loosely fill that little bit of ceiling; move on to the next cavity until that wall was done. Then we'd replace the siding and fill the top half from holed drilled up within a few feet of the eaves.

Jim

[m Ransley]

The new foam that is EPA, and american lung assn approved is Icynene, Spelling im not sure of. But it still needs a cure or out gas time. Summer is the best time for its use. Its around R6 or 7

[Walt Conner]

With regard to the do it yourself foam, our son just checked on it and it was going to cost over $3,000 to do the side walls of his house, blown in cellulose cost less than $200. I would say it will be a lot of years to make up the difference in savings, even with the increasing NG prices.

Walt Conner

[Childfree Scott]

Where do you come up with this $3000 number? When I checked it was $350 + postage?