Hi, I need advice on insulating my old house (105 yrs. old). There is
virtually NO insulation in the attic at all. Between the joists you
can see the lathe and plaster. There are scatterings of insulation here
and there that is basically usless and likely should be removed (since
critters have used it as a urinal).

My question is, if I put down batts of insulation, should I FIRST be
putting plastic down as a vapour barrier. I think I read that some
types of insulation comes with a built in vapour barrier on one side.

I thought that I would remove the old rotted insulation that is
currently there, put in batts of fresh insulation then blow in more on
top. Any suggestions

thanks
Janet

It depends a lot on where you are, weather conditions, home
construction. This is especially true for the vapor barrier. It also
depends on what indoor temperatures you wand and if you have AC or not.

Stretch

Look at the venting & HVAC arrangements.
Check the Building Science Corporation web site.
I have a house from the 1840s in hot humid climate and insulated the
roof rather than the ceiling.
This has worked o.k. for 25 years.
TB

On 21 Aug 2005 21:00:15 -0700, "caledon" wrote:

Hi, I need advice on insulating my old house (105 yrs. old). There is
virtually NO insulation in the attic at all. Between the joists you
can see the lathe and plaster. There are scatterings of insulation here
and there that is basically usless and likely should be removed (since
critters have used it as a urinal).

My question is, if I put down batts of insulation, should I FIRST be
putting plastic down as a vapour barrier. I think I read that some
types of insulation comes with a built in vapour barrier on one side.

You can purchase insulation that is unfaced (no vapor barrier), faced on one
side, or faced on both sides. If you buy the single faced insulation, there
should not be a need to put down a separate barrier. I have never used the
double faced in any application, but would be wary of it in an attic where you
need the insulation to be able to "breathe."

I thought that I would remove the old rotted insulation that is
currently there, put in batts of fresh insulation then blow in more on
top. Any suggestions

Removing the old insulation is probably a good idea. One never knows what has
lived in it, especially over a hundred year span.

If you place bats into the troughs between the ceiling joists, be sure to place
the barrier side down. Do not pour insulation over the bat material. Insulation
depends upon trapped air to provide the heat transfer stoppage between two
spaces. Placing a poured material on top of the (I am assuming fiberglass) will
crush the fiberglass and reduce its designed air volume and thereby reduce the
efficiency of the material.

If you really want to add to the "R" value of the insulation, and don;'t mind a
lot of work, you can cut slabs of Styrofoam insulation to fit be between the
joists and lay that in before putting in the roll material. In this scenario,
the independent vapor barrier would be advisable and unfaced bat material on
the top. Again, do not put anything on top of the Fiberglas that would crush it
down.



Bill Waller
New Eagle, PA

caledon wrote:
Hi, I need advice on insulating my old house (105 yrs. old). There is
virtually NO insulation in the attic at all. Between the joists you
can see the lathe and plaster. There are scatterings of insulation
here and there that is basically usless and likely should be removed
(since critters have used it as a urinal).

My question is, if I put down batts of insulation, should I FIRST be
putting plastic down as a vapour barrier. I think I read that some
types of insulation comes with a built in vapour barrier on one side.

I thought that I would remove the old rotted insulation that is
currently there, put in batts of fresh insulation then blow in more on
top. Any suggestions

thanks
Janet

I agree about removing what is there under those conditions. However I
don't recommend batts for this use. Blown in insulation will provide some
vapor barrier and will help seal air leaks that are likely to be plenty. I
would not use plastic as I have heard of too many situations in these old
homes that doing so ended up trapping moisture where it caused problems.

--
Joseph Meehan

Dia duit

the climate in my area is Canadian winter cold! So having a high R
value is important. I do not want a toasty warm house, I prefer things
a bit cooler, however, I do not want my heating dollars going out the
roof either.

the climate in my area is Canadian winter cold! So having a high R
value is important. I do not want a toasty warm house, I prefer things
a bit cooler, however, I do not want my heating dollars going out the
roof either.

the climate in my area is Canadian winter cold! So having a high R
value is important. I do not want a toasty warm house, I prefer things
a bit cooler, however, I do not want my heating dollars going out the
roof either.

Singe sided bats. If there really isnt too much of the old stuff
remove it. If there are animal dropping etc, take care of that first.

Then seal up and electical holes that you may have. What I mean
by that is high hat or outlet drops that are in the ceiling.

If you do have highhats up there make sure that they are rated
to be up against insulation. If not, the need to be simply boxed
in. (no need for any fires up there)

Do NOT insulate the roof!!! This can create an icedam situation.
This may work for warm weather areas, but you are in canada.
If your into doing all of this, go to one of your local home centers
and simply ask for help.

One thing that I certainly recommend if you do this is that you
get decent dust masks (respirators) when playing with this
stuff. No need killing yourself while saving some money!
Long clothing also helps releive some of the itch factor.

Tom

I had an old house with no insulation in the attic. Had a guy come out
and blow in insulation, it worked well.

I would measure the distance between the joists in several places. If
it's anything like mine, then you'll want to use the blown in variety
to to inconstincies on the spacing.

Using blown insulation you've take the "do it yourself"
part right out. Homeowners dont have access to
that sort of equipment.

Whether or not its better or worse than batt insulation is a
whole nother discussion.

In article .com,
says...

Using blown insulation you've take the "do it yourself"
part right out. Homeowners dont have access to
that sort of equipment.


The equipment is available for free at any Home Depot when you buy the
material. Here is the website for the blown insulation:

http://www.cocooninsulation.com/

DT

I'll say it. Batts suck in Canada in the attic. Why waste your time?
Blown in is better. Cellulose, of course. Foam is even better, but
pricey. I have a definite grudge against fiberglass. In case you
haven't noticed.

Why? see http://www.sustainableenterprises.com/fin/index.htm - but
that's another story...

If you do use foam or cellulose, either a contractor or a
do-it-yourself spray foam kit, be careful you or they don't block the
eave vents if you have the "eave vent to ridge vent" configuration or,
as someone so wisely stated, you'll have a potential problem with ice
dams if the seal isn't complete and moist air gets up into the attic
from the living area.

Hurry up, winter in Canada starts tomorrow! ;0)

abi