Insulation, Radiant and Vapor Barriers - Attic insulation in a 101 year old Victorian

I just purchased a 101 year old Victorian and in all of those years no one has ever put any insulation in the rafters of the roof. Is there a reason why this would not be done? What is the best insulation to use?. I have looked at batts and this is what I want to use but the only R value that I can find that will fit is R19. The rood rafters are 24" on center and made out of 2 X 6. Any suggestions???

If you do mean the roof rafters you want to put up first the foam rafter vents so air can get over the insulation. and paper side down to the room or attic. Is there no insulation over the ceiling below? you can get R13 and R19 in 24" wide.

ED ;)

The floor is finished hardwood. The attic is open and just needs to be finished...insulation in the rafters and drywall. Do you have any information on how to install the vents??

Maybe I should reword that...what are "Foam Vents"??

What really needs to be known is where you live and what are the coldest temps you experience.

I live in Cincinnati Ohio...the winters here are not that bad. I would like to know where to find the foam rafter vents. Anyone know where I can find them?

What are the coldest TEMPERATURES you experience........... in degrees?

I'm not sure what the average lows are for this area. Just guessing I would say around low to mid 20's???? It just depends. Here it is the 2nd of Novermber and it's 65. We have had some very mild winters here.

Well I just checked on the internet and the average low for cincinnati is 31. Does that help??

Home Depot and Lowes have the foam rafter vents. they go up first so that the insulation dont touch the roof . This will let the air from the vents in the over hang get up in there.

ED ;)

What you have to do is make sure that the space between the insulation and the underside of the roof deck is well ventilated, using the foam spacers that Ed suggested.

You also will have to install a well sealed vapor barrier between the insulation and drywall.
This will slow down the infiltration of moisture into the space that would cause a build up of condensation and frost.

This is necessary when outside temps are below freezing.

In addition, you will need to find a way to provide ventilation to the joist space to allow the foam spacers to be able to circulate the air to outside.

Thanks guys I think that tells me what I need to know. Now if I can just figure ou the electric wiring up there...

Out of curiousity, how much space do these foam spacers leave between the insulation and the underside of the roof?

Geoff Check them out at home depot and lowes .Some still have them made out of cardboard. You would have to look around for what they have out there by you for rafter vents

ED ;)

Lowes carrries the foam rafter vents and they are $1.33 each. They are 23" wide by about 3' long and about 1 1/2 high.