Rafters Insulation? - Insulation - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Insulation


Thread Tools Search this Thread
Display Modes
Old 10-12-2012, 04:12 PM   #1
wood hobbyist
Join Date: Mar 2009
Location: Tennessee
Posts: 40
Rewards Points: 25

Rafters insulation?

Ok I'm getting ready to insulate my rafters in a attic playroom I'm finishing. I got my hands on enough "free" 4x8x3/4" foam insulation board to insulate all of the area between the rafters. My question to everyone is this enough insulation or will I have to add Insulation Batts also. So I have about 6-8" of space in the rafter channels to the edge where the sheet rock will go. I have already installed rafter vent baffles and have roof ridge vents for venting. I live in the Memphis area so our winters get as low as teen's and summers get into the 100's.
**corrrection** I got to inspect the foam insulation this weekend and found it to be in different thicknesses 4x8 sheets still, but my choice of 4", 8", and 10" THICK! Again its going in between the rafters not the floor joist.****and its FREE.

Last edited by weberus3; 10-15-2012 at 02:42 PM. Reason: update information
weberus3 is offline   Reply With Quote
Sponsored Links
Old 10-12-2012, 04:22 PM   #2
funfool's Avatar
Join Date: Oct 2012
Location: Albuquerque NM
Posts: 719
Rewards Points: 534

not enough, but some is better then nothing. If it is free or cheap use it.
For best results blow it in, can rent a machine at Home depot and buy the bags of insulation.
Would not hurt to blow it over the foam later, but very little R-value in 3/4" foam, depending on the foam, is probably r-7 or less.
But still better then nothing.
funfool is offline   Reply With Quote
Sponsored Links
Old 10-12-2012, 04:31 PM   #3
Join Date: Nov 2011
Location: Hartfield VA
Posts: 37,133
Rewards Points: 1,906

The baffles are going to take up about 1-1/2" of the avalible space.
I at least add 2 X 2's to the rafters so I can at least add R-13.
joecaption is offline   Reply With Quote
Sponsored Links
Old 10-12-2012, 04:36 PM   #4
An old Tradesmen
Join Date: Oct 2008
Location: Somewhere
Posts: 39,277
Rewards Points: 122

Moved to Insulation forum.
beenthere is offline   Reply With Quote
Old 10-12-2012, 11:47 PM   #5
Registered User
Join Date: Mar 2009
Posts: 11,730
Rewards Points: 526

Appears you are in Zone 4, requiring R-38 in ceilings; http://publicecodes.cyberregs.com/ic..._11_par002.htm


Don't use cellulose in the cathedral areas. I would use Roxul, install full sheets on the rafters for one layer after filling cavities, if you have enough, then drywall. Or just some rips to cover the rafter edges to prevent thermal bridging, foam air-seal one layer of the cavity foam. ADA the drywall; http://www.buildingscience.com/docum...wall-approach/

If any ads are present below my answer or words underlined/colored, I do not condone/support/use the product or services listed/linked to, they are there without my consent.
17,000 dryer fires a year, when did you last clean the inside of the dryer near motor or the exhaust ducting?
Gary in WA is offline   Reply With Quote
Sponsored Links

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cape Cod Style House Attic/Crawl Space Insulation Help Danielg Insulation 24 05-21-2012 08:20 AM
Foam Insulation in Rafters marine02ss Insulation 3 03-30-2012 03:38 PM
Basement Exterior Above Grade Insulation purpasadu Building & Construction 6 02-28-2012 04:42 PM
garage roof insulation between rafters denverman71 Building & Construction 1 10-21-2009 12:06 PM
Old home insulation woes nowwhatnapster Building & Construction 15 11-02-2008 11:59 PM

Top of Page | View New Posts