Need Advice on Rafter insulation

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PJF1313

Member
Oct 25, 2009
389
Pine Barrons, L.I., NY
First of all, a little history of our "new, 3 year old" 1909, according to town records, home.
.
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We are renovating our 1909 ranch style house, as time and funds allow. This past two years, we re-shingled
the siding to 5-1/4" cedar perfections, and re roofed with GAF SlateLine.

After the old siding came down, I saw evidence, at one time, the house had blown insulation installed. It had to
be before the '70's according to the neighbors, and the cedar(12" exposure)-over-homasoate (sp?) installation.
We wrapped the house in DuPont house wrap, and installed the new shingles on fearing strips. I think/feel that the
house wrap has helped a heck of a lot, just by its own - but that just could be me ;-)
.

Last summer we had the roof done. 3, yes 3, layers of asphalt over cedar - and it looked like that last was put on
also in the '70's; it was the interlocking "hurricane proof" type. Had it all stripped to the rafters, 3/4 CDX ply, ice & water
shield, 30# felt put down. GAF SlateLine 40yr shingles, 16ga copper flashing (which I supplied) installed, with a ridge vent.
The house has continuous aluminum sofet vents from the '70's remodel.

Before the roof was redone, it had styrofoam sofet-to-ride vents inbetween the rafters, with no ridge vent to vent to -
no eave, no "forget-me-nots," no NOTHING... Then it had Certenteed faced fiberglass over that, held in place with
those metal insulation holders.

The attic is just under 8' from the floor to the ridge beam, 0" at the sofet. It has carpet over 1x6-10 plank flooring.
The rafters, and the gable ends are 2x6's. The roofers did a GREAT job of destroying what we had there (that's
another subject-hello DA's office?!) leaving us with virtual nothing on the roof, and little on the eaves.

I know a 2x6 is not much, but I was thinking about running 2x6's length wise to gain another 5+" or so.
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Now the question :

What type of insulation would be recommend?

I will be (re)installing the eve to ridge vent - now that it will do something, :) But should I use fiberglass or ridged
styrofaom?

If fiberglass - faced or unfaced? Which way should the facing go?

If styrofoam - less thicker sheets or many thinner sheets? Foil or no?

Vapor barrier?


The attic will remain unheated, but the wife wants a "get away" area. So the possibility of sheetrocking the rafters
MAY come into play.

If pics are needed, LMK - it is still a disaster area as it sits right now. :snake:

Thank you for your time to read this to the end ;-)

Have a Merry Christmas and and Happy, Healthy and SAFE New Year.
 
<> What type of insulation would be recommended?

I will be (re)installing the eve to ridge vent - now that it will do something, :) But should I use fiberglass or ridged
styrofoam?

If fiberglass - faced or unfaced? Which way should the facing go?

If styrofoam - less thicker sheets or many thinner sheets? Foil or no?

Vapor barrier?<>

After installing the "Propervents" or whatever
you're gonna use for your air movement system,
I'd used Kraft-faced fiberglass.
The Kraft-facing goes towards the living space,
acts as a vapor-barrier & gives you a stapling surface.
Use the highest R-rating (R-38?) you can get for the thickness
that you're gonna use.
Make sure your vent system makes it all the way to your soffit vent,
so your insulation doesn't block that cavity...


<>Have a Merry Christmas and and Happy, Healthy and SAFE New Year<>

Right back atcha!
 
I am a framing contractor. I would need pictures to understand what you would like.
 
This is a job for spray foam. You can spray this right against the underside of the deck or use rigid foam wedged between the rafters and covered with foam, in order to leave the vent space.

I'm assuming there's some sort of ladder or stairs, as I can't imagine the wife climbing up a scuttle hole. Whether there's any heat source or not up there, it's going to get a lot of hot air leaking into the space, especially if you don't seal the roof up well.

Spray foam is the quickest and easiest way to get that sealed. You could also use foam between the rafters and foam over all of the rafters then covered with drywall with longer screws, if you can get the sheets up there. You could also drywall it and use cellulose, with or without the vent space.
 
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