Blown In Behind Foam Board - Insulation - DIY Chatroom Home Improvement Forum


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

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 11-04-2012, 12:31 PM   #1
Member
 
Join Date: Jul 2012
Posts: 36
Rewards Points: 25
Default

blown in behind foam board


I'm planning to insulate the ext. walls in my old house and the house is framed with 16'' oc 2x4s, tell me if you think this plan would work.

Flash spf wall cavities for air sealing using home kit
attach 1"-1.5" polyisocyanurate to the studs using plasti-cap nails or screws
blow in cellulose insulation behind the foam board
tuck tape foam board joints
attach 1x furring strips vertically at 16" oc
1/2" drywall
cold climate

Advertisement


Last edited by qc_riderfan87; 11-04-2012 at 01:04 PM.
qc_riderfan87 is offline   Reply With Quote
Old 11-04-2012, 08:12 PM   #2
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 7,088
Rewards Points: 3,244
Default

blown in behind foam board


You planning on the foam to the outside or inside?

If you have the walls open, just use batts or wet spray cellulose. Dense packing is great for an air barrier but if you are going to seal up the walls with SPF, it isn't necessary.

No need for the air space either.

Advertisement

Windows on Wash is online now   Reply With Quote
Old 11-04-2012, 09:42 PM   #3
Member
 
Join Date: Jul 2012
Posts: 36
Rewards Points: 25
Default

blown in behind foam board


can i use batts after the 1 inch of cc spf ill only have 2.5 inches of the cavity left before i put the foam board up. its a big house and i want it tight and insulated, very cold winters here and strong winds. open cell spf i dont know is that as expensive as the cc??
qc_riderfan87 is offline   Reply With Quote
Old 11-05-2012, 07:00 AM   #4
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 7,088
Rewards Points: 3,244
Default

blown in behind foam board


There is no reason that you could not.

Make sure with all these combinations of foam and foam board that you don't created a vapor trap.
Windows on Wash is online now   Reply With Quote
Old 11-05-2012, 09:20 PM   #5
Registered User
 
Join Date: Mar 2009
Posts: 9,972
Rewards Points: 2,010
Default

blown in behind foam board


What is the finish siding?

Any plywood, OSB?

Gary
__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Old 11-05-2012, 11:58 PM   #6
Member
 
Join Date: Jul 2012
Posts: 36
Rewards Points: 25
Default

blown in behind foam board


to fit wouldn't the batt have to be compressed thereby reducing r-value
qc_riderfan87 is offline   Reply With Quote
Old 11-06-2012, 12:00 AM   #7
Member
 
Join Date: Jul 2012
Posts: 36
Rewards Points: 25
Default

blown in behind foam board


Quote:
Originally Posted by GBR in WA View Post
What is the finish siding?

Any plywood, OSB?

Gary
shiplap sheathing on the outside and stucco. (all insulating to be done on inside)
qc_riderfan87 is offline   Reply With Quote
Old 11-06-2012, 09:23 PM   #8
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 7,088
Rewards Points: 3,244
Default

blown in behind foam board


I would put XPS or non-foil faced ISO against the ship lap, spray foam all the seams and the connections to the framing.

Fill the rest of the cavity with a high density batt or roxul.

Air tight drywall.
Windows on Wash is online now   Reply With Quote
Old 11-07-2012, 12:16 AM   #9
Registered User
 
Join Date: Mar 2009
Posts: 9,972
Rewards Points: 2,010
Default

blown in behind foam board


Quote:
Originally Posted by qc_riderfan87 View Post
can i use batts after the 1 inch of cc spf ill only have 2.5 inches of the cavity left before i put the foam board up. its a big house and i want it tight and insulated, very cold winters here and strong winds. open cell spf i dont know is that as expensive as the cc??
----------------

Not a good idea for R-value loss: https://docs.google.com/viewer?a=v&q...SFjptmqEXxrdKQ

With all the foam board in the cavity, the first condensing surface will be inside the f.b., though you will still get a whole-wall thermal loss due to the conducting studs (thermal bridging). This leaves the exterior sheathing colder without the house heat going through the cavity to prevent mold with an exterior water leak or moisture wicking from the stucco (moisture reservoir).

Where are you located?

Gary

Advertisement

__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Reply


Thread Tools
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
Best foam board for knee wall access doors? diyxer Insulation 3 07-09-2012 01:01 PM
Foam board over batts juststarted Insulation 3 12-13-2011 01:12 PM
foam board between joists fubar79 General DIY Discussions 17 10-05-2010 10:38 PM
House wrap over insulating foam board or under?? getn2old Building & Construction 7 07-28-2010 11:53 PM
XPS foam board between basement slab and cement board for ceramic tiles jpsmith Flooring 4 02-10-2009 09:17 PM




Top of Page | View New Posts