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 02-16-2012, 10:37 AM   #1
Member
 
Join Date: Aug 2008
Location: Canada
Posts: 212
Rewards Points: 0
Share |
Default

2" foam or Foil Back?


I have 2 options:
1) 3/8" Foil Back Styrofoam (R5) overtop of existing x90 - without removing x90 for $1700.00
2) Remove x90, housewrap, 2" styrofoam insulation (R10) for $4200.00

I live in Canada


I'm not sure aboout option 1...if you put the r5 overtop of the x90, I think there would be a ton of air gaps as it is lap siding...but how much do you really gain with the r10 and vinyl siding vs r5 + the r value you'd have from your existing x90?

Your thoughts?

hellothere123 is offline   Reply With Quote
Old 02-16-2012, 10:40 AM   #2
Member
 
AGWhitehouse's Avatar
 
Join Date: Jul 2011
Posts: 1,378
Rewards Points: 0
Default

2" foam or Foil Back?


2"@R-10 is XPS and at that thickness is considered a class II vapor retarder. The foil facing is likely considered a class I vapor retarder. Best to make sure you're not creating a double vapor barrier system and create the "Sick building syndrome". The walls need to breath...

__________________
Life's too short...so enjoy it!
AGWhitehouse is offline   Reply With Quote
The Following User Says Thank You to AGWhitehouse For This Useful Post:
Windows on Wash (02-16-2012)
Old 02-16-2012, 02:36 PM   #3
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,242
Rewards Points: 64
Default

2" foam or Foil Back?


Quote:
Originally Posted by AGWhitehouse View Post
2"@R-10 is XPS and at that thickness is considered a class II vapor retarder. The foil facing is likely considered a class I vapor retarder. Best to make sure you're not creating a double vapor barrier system and create the "Sick building syndrome". The walls need to breath...
+1

Foil facing is going to make it Class I in about 99% of the cases.

Be careful of that moisture trap.
Windows on Wash is offline   Reply With Quote
Old 02-16-2012, 05:20 PM   #4
Member
 
Join Date: Aug 2008
Location: Canada
Posts: 212
Rewards Points: 0
Default

2" foam or Foil Back?


I'm sorry...I don't know what you are trying to say...dumb it down for me a bunch!


Thanks!
hellothere123 is offline   Reply With Quote
Old 02-17-2012, 11:13 AM   #5
Member
 
Join Date: Aug 2008
Location: Canada
Posts: 212
Rewards Points: 0
Default

2" foam or Foil Back?


anything further?
hellothere123 is offline   Reply With Quote
Old 02-17-2012, 02:42 PM   #6
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Rewards Points: 0
Default

2" foam or Foil Back?


Please ask the identical question in one forum, not multiple areas, thank you.

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 02-17-2012, 02:46 PM   #7
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Rewards Points: 0
Default

2" foam or Foil Back?


1. How thick are the walls?

2. Is there poly vapor barrier inside? Hence the concern of a faced foamboard outside and poly inside. Unfaced XPS foamboard (2") exterior and poly inside will work if the inside air leaks are stopped.

3. Where in Canada are you located (to find your insulation requirements)?

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 02-17-2012, 08:45 PM   #8
Member
 
Join Date: Aug 2008
Location: Canada
Posts: 212
Rewards Points: 0
Default

2" foam or Foil Back?


Quote:
Originally Posted by GBR in WA View Post
1. How thick are the walls?

2. Is there poly vapor barrier inside? Hence the concern of a faced foamboard outside and poly inside. Unfaced XPS foamboard (2") exterior and poly inside will work if the inside air leaks are stopped.

3. Where in Canada are you located (to find your insulation requirements)?

Gary
Sorry

2x4 walls
vapor barrier is installed on inside
Saskatchewan

I think it should be alright...everyone around here does that..some even go with a R12 insulation on the outside

I'm not totally sold on the benefits vs cost of doing this...

Funny thing is some people will put the 2" foam insulation ontheir house but won't replace the windows until they have the money...I think windows are the biggest loser in terms of losing heat / cold for your house..I dunno
hellothere123 is offline   Reply With Quote
Old 02-17-2012, 11:32 PM   #9
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Rewards Points: 0
Default

2" foam or Foil Back?


Compare the square footage of walls to windows. If older R-9 f.g. batts with air movement, you need the added insulation for your climate. 2" f.b. is fine without facing as I said earlier. No vapor problems: http://docs.google.com/viewer?a=v&q=...4EyM707m0gPdXQ

Cruise around here: http://oee.nrcan.gc.ca/publications/residential/8584

Drain your cladding; http://www.buildingscience.com/docum..._enclosure.pdf

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 02-18-2012, 06:13 PM   #10
Member
 
Join Date: Aug 2008
Location: Canada
Posts: 212
Rewards Points: 0
Default

2" foam or Foil Back?


Thanks..I'll read up
hellothere123 is offline   Reply With Quote
Old 02-19-2012, 07:51 PM   #11
Member
 
Join Date: Dec 2008
Location: South Western Ontario
Posts: 955
Rewards Points: 0
Default

2" foam or Foil Back?


I sided a house in Regina in 1976 with X90. Why not strip down in the spring and do it right. For the money you will spend you can probably pay a couple of kids $100 each and dig in. For the improved level surface it will likely pay you back in a proper seal and fight off those COLD winters!!!!At least if you strip it you can use up to date material and inspect the whole structure, seal your windows, etc.

Chemist1961 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
Crawlspace Wall Insulation Earnie Building & Construction 28 10-23-2012 06:59 PM
How to patch around a 2" x 4" hole in back of furnace darlingm HVAC 16 08-22-2011 06:22 AM
Using Foam Insulating Sheathing over Studs wiz561 Building & Construction 4 08-28-2010 09:53 PM
Need help making a 'back band' around window/door casing. RickDel Carpentry 3 07-15-2010 03:13 PM
closed cell vs open cell foam insulation amonalisa Building & Construction 1 11-06-2008 09:39 PM




Top of Page | View New Posts

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