If your house is 103 years old, you will not have drywall to fix. If
you install the insulation from the inside, you will be repairing the
plaster and lath. I cannot imagine how they will make "holes" in the
plaster to blow the insulation into the walls, and then repair the
holes.

In our old house, I opened one or two lath strips of plaster from
near the top of walls, and then looked into the wall with a small mirror
and light to see what kind of blockages were there. Then I used old
loose-fill and new cellulose, dropped into the channels, periodically
tamping it with a small piece of pipe on a string, and finally when it
got to within reach, I used fiberglas to finish it off AND to block the
areas above my hole which extended out into the ceilings.

The specifics varied depending on the walls and ceiling joist
orientations, whether there were windows above/below involved, and many
other things.

Subsequent work around window areas has revealed areas there which
needed filling, and it also showed that after ten years or so there does
not seem to be any settling. But the plaster/lath with keying probably
holds the insulation in place.

I have learned to do fairly nice plaster work (with Gypsum and diamond
white plasters in a two coat procedure). And I would note that doing
WALLS makes a LOT of difference in both heating and noise!!

Lesley wrote:

I'm back again, this time it's insulation. My house is 103 years old
and never has been insulated. So I got a quote from a local company
and I didn't realize it would be so expensive. If they blow it in from
the outside, it costs $2300 but if they do it from the inside it's
$1750. But then I have to pay a drywaller to fix the gazillion holes
they will make because they only do the initial rough patch after they
blow in the insulation. We're talking about a LOT of holes.

Then there's the attic. I got a quote for the recycled denim
insulation up there and it was over $1,000. So I asked what it would
cost to use the normal stuff (fiberglass pink stuff) and he said they
don't use that because it's way less efficient than the recycled denim
and plus it's not healthy to have around.

So I'm not just writing to whine. I have two questions.

1. Is it true that fiberglass is much less efficient than the recycled
denim?

2. Someone told me that blown-in cellulose will settle in a few years
and then I'll be right back where I started. The contractor said he'd
give me a 15 year warranty, but he doesn't have one in writing--it's
just his good word since "it's a family business".
Could I have some comments on cellulose insulation in general and
whether this is something I really need to just DO and stop whining
about?

Thanks again in advance. This group is really helpful for me.

Best,

Lesley

--
Phil Munro Dept of Electrical & Computer Engin
Youngstown State University
Youngstown, Ohio 44555