Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


Go Back   DIY Chatroom Home Improvement Forum > DIY Repair > General DIY Discussions

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-15-2007, 12:10 PM   #1
Newbie
 
Join Date: Oct 2007
Posts: 2
Share |
Default

Insulate basement header with imbedded joists???


I have a 1962 house with insulated basement walls. Problem is the headers were not insulated. I have read that its wise to insulate basement headers where about 40% of heat is lost in cold winter climates like the one I live in (Wpg. Manitoba).

I have insulated the header at the wall where the header run parallel to the joists.

Problem: I have read that it is unwise to insulate headers where the joists are embedded in concrete although the reason was not given.

My floor joists are imbedded in concrete.....

Any suggestions about what I should do to insulate these embedded headers??

Thanks,

lackofunds
lackofunds is offline   Reply With Quote
Old 10-15-2007, 11:39 PM   #2
Newbie
 
Join Date: Sep 2007
Location: Middle Tenn
Posts: 27
Default

Insulate basement header with imbedded joists???


My guess as to why it is unwise to insulate where wood meets concrete, is due to condensation. The concrete being cold and wood being warm creates condensation and it needs to be able to breathe. If you insulate it, you will trap the moisture in and it will rot the wood.

I just saw this on Holmes on Homes earlier this evening, lol.
97catintenn is offline   Reply With Quote
Old 10-16-2007, 03:54 AM   #3
Lic. Builder/GC/Remodeler
 
AtlanticWBConst.'s Avatar
 
Join Date: May 2006
Location: New England
Posts: 7,556
Default

Insulate basement header with imbedded joists???


Quote:
Originally Posted by lackofunds View Post
Any suggestions about what I should do to insulate these embedded headers??
Thanks,
lackofunds
Hopefully all that imbedded wood is pressure treated. Judging by the age of your home, it may not be. If it is not, your best bet is to not touch it, for the reasons that the previous poster listed.
If it is PT, then you can use ridgid foam board attached with construction adhesive and galvanized fasteners (nails or screws)

Last edited by AtlanticWBConst.; 10-16-2007 at 03:56 AM.
AtlanticWBConst. is offline   Reply With Quote
Old 10-19-2007, 01:01 PM   #4
Newbie
 
Join Date: Oct 2007
Posts: 3
Default

Insulate basement header with imbedded joists???


Natural Resources Canada - Office of Energy Efficiency has helpful information on insulating basements (http://www.oee.nrcan.gc.ca/residential/personal/new-home-improvement/choosing/insulation-sealing/basement/khi-inbasement.cfm?attr=4).
They recommend not insulating the joist spaces where joists are embedded. Air sealing these areas is recommended.
I am about to insulate my 100 year old house which has embedded first and second floor joists. I guess the only way to totally insulate the exterior walls is to apply insulation to the exterior but I don’t want to cover up my brick.
Any other ideas on how to maximize insulation while protecting the embedded joist ends from rotting?
chris33 is offline   Reply With Quote
Old 12-02-2008, 11:10 AM   #5
Newbie
 
Join Date: Dec 2008
Posts: 4
Default

Insulate basement header with imbedded joists???


Does it matter if the joists are above grade or not? Would spray foam work? or is that a bad idea too?
cabber24 is offline   Reply With Quote
Old 01-02-2009, 12:39 PM   #6
mwh
Newbie
 
Join Date: Jan 2009
Posts: 2
Default

Insulate basement header with imbedded joists???


i have the same issue. i can't see why if you properly vapour barrier or use spray foam so there is no chance of moisture becoming trapped that it is a problem to insulate between joists. unless they're scared moisture is coming in via a crack in the foundation?
mwh is offline   Reply With Quote
Old 01-02-2009, 05:03 PM   #7
Member
 
Join Date: Nov 2008
Posts: 96
Default

Insulate basement header with imbedded joists???


The joist are going to pick up ambient heat from the house and transfer it down the length of the joist to where they are embedded, where heat meets cold it will create moisture. Spray foam or vapor barrier isnt going to matter, therefore they will need to breathe. Some times 100 yr old houses suck.
JCAHILL4 is offline   Reply With Quote
Old 01-02-2009, 07:23 PM   #8
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Default

Insulate basement header with imbedded joists???


Hmmmmmmmm! My daughter has an older home that has a standard box frame construction! At some point, some enterprising sole filled the joist cavities with house brick! Mortared in place! I installed rolled insulation from the sill plate down to the 4 foot mark! ( it came with attached vapor barrier) Using R12 bat insulation, I faced the bricks in the cavities, and ran the v/b over top! The question is, am I facing the same problem as if the joists were embedded?
Wildie is offline   Reply With Quote
Old 01-03-2009, 12:58 PM   #9
Member
 
Join Date: Oct 2008
Posts: 92
Default

Insulate basement header with imbedded joists???


what are embedded joists?
troyce1 is offline   Reply With Quote
Old 01-03-2009, 06:35 PM   #10
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Default

Insulate basement header with imbedded joists???


Quote:
Originally Posted by troyce1 View Post
what are embedded joists?
When the forms are built for the foundation, the joists are put in place before the cement is poured! The cement is brought up to the level of the top of joists, thus filling the joist cavity with concrete! Its my guess that this methed of construction died out in the period of around 1920. At least I have never seen this on newer buildings!
Wildie is offline   Reply With Quote
Old 01-03-2009, 11:59 PM   #11
mwh
Newbie
 
Join Date: Jan 2009
Posts: 2
Default

Insulate basement header with imbedded joists???


my joists are embedded in the foundation wall however extend through to the ouside 2x8 end plate, my house was built in '59. because my joist run to the outside end plate they will breathe to the outside therefore it shouldn't matter if i insulate the joist space...correct?
mwh is offline   Reply With Quote
Old 01-11-2010, 05:37 PM   #12
Newbie
 
Join Date: Jan 2010
Location: Kitchener, Ontario
Posts: 1
Default

Insulate basement header with imbedded joists???


Quote:
Originally Posted by Wildie View Post
some enterprising sole filled the joist cavities with house brick! Mortared in place! The question is, am I facing the same problem as if the joists were embedded?

Just like Wildie, I'm facing the issue of house brick mortared in between the joists (which otherwise sit on top of a poured foundation). The whole inside wall is plastered smooth; a quarter inch of plaster top to bottom, finishing the wall from the bricks up in between the joists right down to the basement floor.

I want to insulate the header area, but I worry these are effectively embedded joists.

Is it safe to insulate in this sort of semi-embedded header space? I can understand the moisture concerns... concrete will generate moisture, and wood will hold it. But my foundation runs high up off the ground and there's little hint of any moisture problems anywhere.

I'd like to go for it.
Schultz is offline   Reply With Quote
Old 01-11-2010, 09:21 PM   #13
Registered User
 
Join Date: Mar 2009
Posts: 9,886
Default

Insulate basement header with imbedded joists???


  • Rim joist assembly must be insulated with air impermeable insulation
  • Interior air cannot access concrete condensing surface or rim joist condensing surface due to spray foam layer
  • Spray foam insulation layer is vapor semi-permeable permitting inward drying
  • Spray foam must be covered with fire/ignition barrier Highlights mine. From under Fig.4: http://www.buildingscience.com/docum...t%20insulation
Another good read: http://www.buildingscience.com/docum...gs?full_view=1 There is also one on stone foundation insulation.

Be safe, Gary
__________________
Clothes taking longer to dry?
Clean the dryer screen in HOT water if using fabric softener sheets.
They leave a residue that impedes air-flow, costing you money.
Clean the ducting in the last six months? 17,000 dryer fires annually!
Gary in WA is offline   Reply With Quote
Old 01-11-2010, 09:30 PM   #14
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 12,943
Default

Insulate basement header with imbedded joists???


I used Kraft faced R-13 around my basement Rim Joist & header pockets. It has helped a lot in stopping the cold. That along with using Window & Door foam to seal a few cracks between a couple of joints on the sills, and basement window headers. Next year, the windows are getting replaced with more energy efficient, since they have been in the house for over 70+ years, and when we reglazed them last year, used Lexan, because it was cheaper at the moment.
gregzoll is offline   Reply With Quote
Old 12-03-2010, 01:38 PM   #15
Newbie
 
Join Date: Dec 2010
Posts: 4
Default

Insulate basement header with imbedded joists???


This worry about trapping moisture is really a headache, and I wonder if it's even justified. Isn't concrete and brick ultimately breathable to the outside? In that case, doesn't moisture just find its way to the outside no matter what?

I could see if both the outside and the inside surfaces were sealed, leaving a warm wood channel to meet with cold concrete in a locked chamber...

This is driving me nuts because I had an energy audit done (on my 1905 house), wherein the auditor told me to insulate the basement headers. When I went back to him about this "moisture risk", he didn't seem to know/ think much about it.

Are we listening to these Holmes guys too much? Does anyone really know what's going on with moisture/ air/ heat??

Sorry, just venting (a pun in there to make me calm down).
policestyle is offline   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
Spray foam insulating joists in basement? peethree Building & Construction 13 11-28-2010 08:54 AM
Necessary to insulate basement ceiling between joists? yummy mummy Building & Construction 12 02-06-2009 11:19 PM
Where to insulate in basement...? DIY4EVER Building & Construction 5 07-27-2007 12:33 PM
basement framing, walls parallel to joists DIY4EVER Building & Construction 8 06-06-2007 03:08 PM




Top of Page | View New Posts

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