Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

R... Whatever Attic Insulation

gwoods's Avatar

Join Date: Mar 2001
Posts: 42

03-20-01, 12:32 PM   #1  
My attic has never been insulated and I want to install some. I've been told I need R13, R20, R30, R38... So I've had enough! What type of insulation should I get. Should It come with a vapor barrier or should I manually lay a plastic or similar barrier.

Sponsored Links
Resqman's Avatar
Visiting Guest

Posts: n/a

03-20-01, 12:58 PM   #2  
Most states require R-38 in ceilings which is 12" of fiberglass. You would need a vapor barrier and it would go closest to the living space.

R-19 would be 6 inch fiberglass batt insulation. Assumming you have 2x6 joists, you could install 6" with kraft paper vapor barrier next to the ceiling between the joists and then install a second layer of 6" with no vapor barrier overtop. Or you could have 12" blown in.

Those would be the two most common methods. There are alternate insulating materials and methods of installation.

R-13 is 3.5" fiberglass and is used primarily with 2x4 wall studs.

's Avatar
Visiting Guest

Posts: n/a

03-22-01, 05:21 PM   #3  
Correction, 12" of insulation is an R30 rating.... And, it is generally what is required in attics.

I work for an insulation company and we started using cellulose insulation a while back. We highly recommend it for attics. It only requires 8" for an R30 rating, it is fire rated, it's treated with boric acid (keeps down on the critters), and you get a "true" R30 value as it gives a complete seal. The company that we get the insulation from also guarantees that the material will not settle........ ever.

You may want to consult several insulation companies and decide to have either fiberglass or cellulose installed for you.

Search this Thread