Dec 19, 2013, 02:30 PMgrampa john
hi happy holidays I just roofed myhouse I cut ridge vent on top of roof I have blown fiberglass insulationin....o..house is30 yrs old should I add more insulation also should I put insulatin between roof rafers and what r factor thanks
Dec 19, 2013, 03:14 PMJaybee
Insulation is best as you have it - blown in on top of the ceiling joists. No need to insulate in-between the rafters.
The important thing is to make sure you have a clear air path from your soffit vents to your ridge vents. An attic space needs both sets of vents to work. With blown-in insulation, you usually need to add some cardboard or foam baffles to keep the soffits clear. As long as you have an air path from low to high, then more insulation will not hurt. Current recommendations are for R-38 in attic spaces - that's about 15" of blown in fiberglass.
Dec 19, 2013, 06:25 PMFrodo
grandpa...go crazy like me...i used that new fluff up wuite stuff from the pink panther..artic something or the other
kinda blew it on my calculations..must have 20" up there..i damn near buried my new ac unit...had to dig it out..it will settle down to a good 12" in a year or 2