insulation questions

[caledon]

Hi, I have posted before re: my insulation in attic question....I am now at the next stage. i have removed all the critter soaked old insulation out of my century home (105 years) and now have to re-insulate. How is the question. After taking out the insulation, the floor of the attic is plaster and lathe. Not in good shape in some places...fine in others. I am located in Ontario, Canada, north or Toronto. Very cold winters! I have differing opinions between the blown in vs. batts. Vapor barrier or not. I do not want to tear down the existing plaster that is the ceiling of the top floor/floor of the attic. I talked to Home Depot regarding using batts. You can no longer get batts that have the paper siding that acts as a vapour barrier. I do not want to have to put plastic down between every joist if at all possible. The home depot "guy" said, all I have to do is lay the batts down between the joists (R20)then lay more batts the opposite direction (again R20) for a total of R40, then put ?mil plastic over top, stapling to the joists. I would think that this would cause condensation between the plastic and the ceiling/floor of the attic. He insisted that this is how it is done. I would have thought that the plastic would have to go down first, followed by batts. I would rather avoid having to do this, since I am doing the job myself, winter is fast approaching and the prospect of taking on such a job (the plastic) on my own.....makes me want to run and play in traffic. I don't want to accept what he is saying just because it is what I want to hear.....

My question is...is he right? Batts on top of the plaster and lathe, then plastic? Would blown in insulation be best? I would appreciate some advice...asap...since winter is fast approaching...

thanks in advance for any advice. btw, pics of attic are here...

regards janet

[Bob]

I would suggest that you need a better source of information. I am sure that faced batts are still available. Just because H.D. doesn't have them means nothing. H.D's selection is pretty limited. And the vapor barrier info you got is dead wrong.

Bob

[Wayne Whitney]

The vapor barrier goes on the warm side of the surface. So for houses in cold climates, it goes towards the living area. Your quote above is definitely wrong, you need the vapor barrier first, then the batts. I'm surprised that you can't get batts that have a paper vapor barrier on one side.

As to batts versus blown in, I have no experience.

Wayne

[W. Wells]

I live in NC. I had blown in insulation in my attic. I had it put on top of

[Speedy Jim]

Just to back Wayne up- in winter climate, vapor barrier

*must* go on warm side (under the insulation).

A couple years ago, I tried an experiment. This is Northern Ohio winter climate. No vapor barrier in ceiling.

2 layers of unfaced fiberglass.

Over the top fiberglass batts, I laid a sheet of plastic. It even had rows of ventilation holes in it. After a week, I went up and inspected the insulation; it was soaked through from condensation. In effect, it had been "raining" under my plastic sheet! End experiment

Jim

[Insulation]

Just so you know,

I few weeks ago I got estimate on blown in insulation in Ontario, Richmond Hill. Price was:

63cents/SQ foot

• GST. I believe they talked about 6inches of fiberglass.

Compare this with bats and decided what is cheaper.

[Sherman]

The vapor barrier location changes depending on where the most water vapor (moisture) is coming from. Some times it comes (mostly) from the house and sometimes it comes from outside.

I would think that you have very dry air in your house most of the winter, right? Do you have to use a humidifier to keep the 'heated' air moist enough to breathe?

I think I agree with your home depot guy. The outer barrier will keep the dust and moisture from destroying your new insulation.

But in your shower walls and ceiling, put a vapor barrier directly against the wall.

[caledon]

thanks for the advice. I knew that Home Depot guy must have been wrong. I asked him twice if he was sure...cause it didn't sound right to me. Other than plastic, what else could I use as a vapour barrier...if the batts are not available with paper siding, what if I put heavy duty paper down then the batt on top....?

BTW, both Home Hardware AND Home Depot said the paper sided batts are not available...

thanks aga> I would suggest that you need a better source of information. I am sure that

[Joseph Meehan]

It will be moving from the warm side to the cool side. Always put the vapor barrier on the warm side. In most areas that is the inside, in a few areas where A/C is run most of the year, that is the outside.

[Chantel]

Have you though about using sprayed foam insulation? As you are in the US, you would have to buy it from fomo: their website is

Although, do have a look at th spray insulation website as it does give a lot of practical information, although as already said, you would have to buy it from fomo.

[Bob]

list "kraft faced" batts of various levels of insulation.

Look up insulation suppliers in your local yellow pages. Again - H.D. type stores don't stock much anymore.

Bob