On Apr 7, 7:34 am, "Big_Jake" wrote:
On Apr 6, 11:45 pm, wrote:



On Apr 6, 6:31 pm, "Joseph Meehan" wrote:

wrote:
I'm in Fort Worth, TX and when I look at an online chart for the 'R'
value of insulation I would need for my attic, it tells me 49. (about
14" of cellulose. I think)

At the local DIY store they tell me that this is really overkill and
that about 30 will do about all I need.

Since we will be doing the 'blowing in' ourselves, I would appreciate
it if someone who has done this themselves, in this area, would care
to give their opinion of what 'R' value I will need.

Thanks.

Lewis.

*****

There are local minimums. I consider them just that. More is always
better, but there comes a time when it becomes un-economical to go higher.
Few people go that high. More efficient systems will mean less payback from
insulation, but as time goes on, you can bet the cost of energy is going
nowhere but up so I would suggest erroring on the high side. Don't forget
to add additional insulation for any ducts that are running up in that
attic.

--
Joseph Meehan

Dia 's Muire duit- Hide quoted text -

- Show quoted text -

Your original post said you were blowing yourself. I hope you saw the
reply about vapor barrier. I am near Chicago and our requirement is R
30. Typically a 6" R-19 batt with vapor barrier (always facing the
inside) then blow on about 6 inches to get a consistant blown R-11
after settling. The next big issue is the attic ventilation. Buy foam
chutes at the local home store to prevent the insulation from
contacting the sheathing near the edges. This allows air to travel
from the soffit vent up to the high roof vents. Without proper vapor
barrier and ventilation you don't gain from insulation, it causes more
trouble.

Dave Scudamore
Aroundtoit Handyman

We are adding on to our house, and when I talked to my inspector about
vapor barrier, he downplayed the need for it, indicating that we could
use a primer under our paint which would be rated as a vapor barrier.
He said that as long it had a rating of 1 perm, it would be ok.

JK

I know they make a paint that is supposed to be a vapor barrier. I
would want to hear it from the paint dealer that his product is a full
and complete replacement for the attic vapor barrier, not just a
supplement. I owned and operated a home inspection company in the
early 90's. You would be amazed at how many houses had the insulation
installed upside down. Obviously, the city code inspector passed them
when it was built. This traps vapor (read water) in the fiberglass
with no means to disperse. Molded drywall results. If the warm moist
inside air contacts the colder atmospheric temperature of a properly
vented attic, condensation occurs. I know you don't have varying
temperature like we see in Chicago but if they specify that much
insulation they must expect it to insulate the home interior envelope
from some exterior temperature extreme. Better safe than sorry.

Dave Scudamore
Aroundtoit Handyman