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

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-11-2013, 02:23 PM   #1
Member
 
Join Date: Aug 2009
Location: Asheville, NC
Posts: 46
Rewards Points: 25
Default

Insulating Rim Joist - caulk or spray foam around edges?


I am getting ready to insulate the rim joists in my unfinished basement and am intending on using 2" XPS and sealing around edges with either caulk or spray foam (Great Stuff). Is one better than the other? easier? more cost efficient?

If using caulk, is there a certain type that I should use?

Thanks

markley is offline   Reply With Quote
Old 01-11-2013, 02:30 PM   #2
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 26,992
Rewards Points: 3,100
Default

Insulating Rim Joist - caulk or spray foam around edges?


Spray foam would be my choise.

joecaption is online now   Reply With Quote
Old 01-11-2013, 02:30 PM   #3
Member
 
Join Date: Oct 2009
Location: Minneapolis, MN
Posts: 501
Rewards Points: 502
Default

Insulating Rim Joist - caulk or spray foam around edges?


I believe that the word on the street is that you should caulk to prevent gaps from expansion and contraction. Did I use caulk when I did mine? No, I used expansion foam. So what. I got it to 99% perfect instead of 100% perfect. it is still a million times better than what it was.

B
Beepster is online now   Reply With Quote
Old 01-11-2013, 02:32 PM   #4
Member
 
Join Date: Aug 2009
Location: Asheville, NC
Posts: 46
Rewards Points: 25
Default

Insulating Rim Joist - caulk or spray foam around edges?


Thanks for the quick replies! I am guessing spray foam is easier as well?
markley is offline   Reply With Quote
Old 01-11-2013, 02:38 PM   #5
Newbie
 
ocd carpenter's Avatar
 
Join Date: Dec 2012
Location: Ontario
Posts: 18
Rewards Points: 10
Default

Insulating Rim Joist - caulk or spray foam around edges?


Caulk is cheaper. If you have a big caulking gun, the big 850mL tubes of acoustical sealant end up being about half the price of the small ones for what you get, up here in Canada anyway. I just did mine and I used a combination of the caulk and foam, depending on the size of the gap.
ocd carpenter is offline   Reply With Quote
Old 01-11-2013, 06:04 PM   #6
Member
 
SuperJETT's Avatar
 
Join Date: Oct 2012
Location: Loo-uh-vul, KY
Posts: 195
Rewards Points: 150
Default

Insulating Rim Joist - caulk or spray foam around edges?


Great Stuff Pro would be my choice. It's what I've been using to do ours. Excellent control and no waste like the regular cans.
SuperJETT is offline   Reply With Quote
Old 01-11-2013, 08:20 PM   #7
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 6,623
Rewards Points: 2,528
Default

Insulating Rim Joist - caulk or spray foam around edges?


Either or will work just fine.

Spray foam is usually easier.
Windows on Wash is online now   Reply With Quote
Old 01-12-2013, 02:50 PM   #8
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Rewards Points: 2,000
Default

Insulating Rim Joist - caulk or spray foam around edges?


I'd caulk (allows slight movement) the wood joints at rim/joists and canned foam the f.b. perimeter, (except the bottom- use caulking there for movement) double air-sealed. The caulk/sealant would stop any air movement between joist cavities behind the foamboard. Fig. 2; http://www.buildingscience.com/documents/information-sheets/crawlspace-insulation/

Did you notice Fig.3- the adhesive on top the foamboard and the sealant/caulk on the bottom for movement. The rim joist, if solid wood rather than engineered wood, will move slightly with the seasonal changes; pp.51- chart (though that is for new wood and after first seasonal changes) after that changes will be less, depending on outside humidity.http://books.google.com/books?id=iwS...joists&f=false

The canned foam/f.b. will stop exfiltration of basement air getting to the rim surface but that is only 1/2 the solution. You need the caulking on the rim (behind the foamboard) to stop infiltration for a complete seal of air moving both ways. Otherwise the outside air could condense on the inside of rim, behind your air-sealed f.b. defense... smaller cells caulk pattern, in BOLD; http://joneakes.com/jons-fixit-database/743

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 01-15-2013, 08:58 AM   #9
Home Performance
 
HomeSealed's Avatar
 
Join Date: Jan 2008
Location: Milwaukee,WI
Posts: 1,448
Rewards Points: 530
Default

Insulating Rim Joist - caulk or spray foam around edges?


Good advice above... Spray foam will probably be a little pricier, but easier to work with. It can be really awkward to maneuver a caulk gun in that tight space.
__________________
Replacement Windows, doors, siding, roofing, insulation, and certified energy consulting.
www.HomeSealed.com
HomeSealed is offline   Reply With Quote
Old 01-15-2013, 09:26 AM   #10
Member
 
Join Date: Oct 2011
Location: Ohio
Posts: 2,557
Rewards Points: 2,022
Default

Insulating Rim Joist - caulk or spray foam around edges?


I had 162 lineal feet of rim joist done by a local spray foam company. Dont mind the dimensions on the chandelier. I was trying to sell it in that photo.

Before all I had was fiberglass stuffed in the rim joist cavities. After all sealed up with spray foam.
Attached Thumbnails
Insulating Rim Joist - caulk or spray foam around edges?-after.jpg  

Last edited by hammerlane; 03-05-2013 at 09:09 AM.
hammerlane is online now   Reply With Quote
Old 01-15-2013, 09:29 AM   #11
Newbie Bill
 
Join Date: Dec 2008
Location: Alberta, Canada
Posts: 1,056
Rewards Points: 500
Default

Insulating Rim Joist - caulk or spray foam around edges?


Hammerlane, do you mind me asking how much that cost you?
__________________
Bill

A DIY Noob that knows just enough to be dangerous.
drtbk4ever is offline   Reply With Quote
Old 01-15-2013, 11:36 AM   #12
Member
 
Join Date: Oct 2011
Location: Ohio
Posts: 2,557
Rewards Points: 2,022
Default

Insulating Rim Joist - caulk or spray foam around edges?


Quote:
Originally Posted by drtbk4ever View Post
Hammerlane, do you mind me asking how much that cost you?
$800 for 162 lineal feet of rim joists in the basement and a 200 sq foot of wall space in an attic area above a garage.

Attached are a few photos:

A few photos below of the before and after of the area above my garage.

After they did the spray foam in the attic area I fluffed up all existing batt insulation and laid new batts across the joists.
Attached Thumbnails
Insulating Rim Joist - caulk or spray foam around edges?-att-b4.jpg   Insulating Rim Joist - caulk or spray foam around edges?-att-after.jpg   Insulating Rim Joist - caulk or spray foam around edges?-side-wall.jpg  

Last edited by hammerlane; 01-15-2013 at 12:37 PM.
hammerlane is online now   Reply With Quote
The Following User Says Thank You to hammerlane For This Useful Post:
drtbk4ever (01-15-2013)
Old 01-15-2013, 12:08 PM   #13
Member
 
SuperJETT's Avatar
 
Join Date: Oct 2012
Location: Loo-uh-vul, KY
Posts: 195
Rewards Points: 150
Default

Insulating Rim Joist - caulk or spray foam around edges?


That's a good price IMO. I have a friend who owns a spray foam company here that I've talked to several times about pricing and it's not as bad as it's made out to be on here.

For our house, he gave a quick verbal quote of around $500 for the rim joist area though probably higher due to one section that's hard to get to and will take more time.
SuperJETT is offline   Reply With Quote
Old 01-15-2013, 12:11 PM   #14
Home Performance
 
HomeSealed's Avatar
 
Join Date: Jan 2008
Location: Milwaukee,WI
Posts: 1,448
Rewards Points: 530
Default

Insulating Rim Joist - caulk or spray foam around edges?


That's a VERY good price. Around here, the going rate would be higher than that for the rim joist alone, without that attic wall.
__________________
Replacement Windows, doors, siding, roofing, insulation, and certified energy consulting.
www.HomeSealed.com
HomeSealed is offline   Reply With Quote
Old 01-15-2013, 12:41 PM   #15
Member
 
Join Date: Oct 2011
Location: Ohio
Posts: 2,557
Rewards Points: 2,022
Default

Insulating Rim Joist - caulk or spray foam around edges?


Initial price was $1000. About a month later the compnay called me on a Tuesday night and said they had cancellation on Thursday morning and they would give me a $200 discount if I were to schedule in that slot. I took them up on it.

hammerlane is online now   Reply With Quote
Reply


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
Insulating Basement w/ Rigid Foam and Batt Reilley Building & Construction 4 08-03-2013 10:07 PM
Spray foam insulating joists in basement? peethree Building & Construction 13 11-28-2010 08:54 AM
Closed Cell Spray Foam with Fiberglass? ddave23 Building & Construction 1 10-28-2009 01:54 PM
Closed Cell Spray Foam insulation and hiring a contractor. Spud Building & Construction 2 10-14-2009 09:03 AM
Insulating - Rim/Header Joist - Basement AndrewF Building & Construction 7 02-26-2009 11:10 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.