OK, the house is 53 years old, and I have been here 30 years and had only gone up the attic once to wire a fan and once to install a bathroom vent. I had never looked close at the insulation and always assumed that I only had an R-19, so I contracted to upgrade for zone 6 standard of R-49.
So I go up and look at it again before the contractor shows up and discover that I had a 6" batt on top of a 2-1/2 or 3" foil faced batt. I had already agreed to pay for 10-12" of blown in insulation so the contractor said to just install it anyways, the contract was already signed.
What I notice up there is that there were no proper vents and only gable vents. 10 years ago when I had vinyl siding installed, I had told the Contractor to rip a slot under the plywood soffit in-between the small vents I had and he never did it and installed the perforated vents over the plywood and called it good.
Well, so much for soffit venting.
I also noticed the condition of the plywood and lumber, which is amazing condition considering the little insulation and just gable vents. My shingles are pushing 30 years now and look great still.
So forget the proper vents and get her done. LOL!
That is the foil face under the 6"
New 12" fiberglass R-30 +
So now I have approx. a R-60
and no soffit venting. I will check it out again when I redo my roof in a few years.