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 04-26-2012, 06:48 PM   #1
Newbie
 
Join Date: Apr 2012
Posts: 20
Share |
Default

Insulation Conundrum


I've tried looking for an answer to my insulation woes but I just get cross answers. I have a house built in 1953 in the Washington DC area. I was able to increase the insulation in the attic last year and I hope to do something about the walls soon. They have nothing but a fiberboard sheathing and old siding. I want to replace the siding which seems like a great time to do some air sealing and insulating. But how much and what options to choose is the question of the day. I have heard that blowing in cellulose from the outside without a vapor barrier on the wall side is a bad idea. I've read that if you vapor barrier the outside and then a layer of ridged foam that the cellulose is ok. Then there is insulated vinyl siding to consider. I know it only has a R value of about 2 but every bit helps doesn't it? I need help. Whats would be the best option without tearing into the inner walls? If you don't blow in cellulose should you house wrap then foam board on top? Please guide me out of this mess.

Lioncourt is offline   Reply With Quote
Old 04-26-2012, 07:05 PM   #2
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,010
Default

Insulation Conundrum


If you are looking for R-Value, don't be under the misguided impression that the foam backed siding products give you any.

This climate does not require a vapor barrier so the installation of one specifically would be uneccesary and potentially problematic.

If stripping the existing siding, now is your chance to fix a great many issues in the exterior wall insulation.

Pull everything down, air seal the larger gaps and cracks in the interior wall, install proper depth insulation, rigid foam to the exterior (tape and seal all seams) in a sufficient enough depth to prevent dewpoint, new siding.

Windows on Wash is online now   Reply With Quote
The Following 2 Users Say Thank You to Windows on Wash For This Useful Post:
ben's plumbing (04-26-2012), Tom Struble (04-28-2012)
Old 04-26-2012, 07:18 PM   #3
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 26,248
Default

Insulation Conundrum


http://www.energystar.gov/index.cfm?...sulation_table
joecaption is offline   Reply With Quote
Old 04-26-2012, 08:59 PM   #4
Newbie
 
Join Date: Apr 2012
Posts: 20
Default

Insulation Conundrum


Quote:
Originally Posted by Windows on Wash View Post
If you are looking for R-Value, don't be under the misguided impression that the foam backed siding products give you any.

This climate does not require a vapor barrier so the installation of one specifically would be uneccesary and potentially problematic.

If stripping the existing siding, now is your chance to fix a great many issues in the exterior wall insulation.

Pull everything down, air seal the larger gaps and cracks in the interior wall, install proper depth insulation, rigid foam to the exterior (tape and seal all seams) in a sufficient enough depth to prevent dewpoint, new siding.
Stripping the sheathing is probably cost prohibitive and perhaps excessive?
Lioncourt is offline   Reply With Quote
Old 04-26-2012, 09:39 PM   #5
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,010
Default

Insulation Conundrum


We usually find the fiberboards are trashed on and full of holes. They certainly are not real structural members and are removed pretty simply.

Depending on the structure of the home, you don't need to re-sheet the exterior and can apply the foam directly over the studding.

Dense packing cellulose would be more cost prohibitive than pulling the sheathing and installing traditional batting.

Pulling the board also allows you the ability to foam and seal any penetrations in the interior wall/envelop layer.

I agree with you that it is more expensive, however, I would be willing to bet that if you are doing foam and batting, it would probably be cheaper than foam and dense packing.
Windows on Wash is online now   Reply With Quote
The Following 2 Users Say Thank You to Windows on Wash For This Useful Post:
ben's plumbing (04-26-2012), Ravenworks (04-28-2012)
Old 04-27-2012, 11:31 AM   #6
Newbie
 
Join Date: Apr 2012
Posts: 20
Default

Insulation Conundrum


Interesting, I've never heard of a house without some form of sheathing (not just foam) I know the fiberboard isn't much for rigidity but Shouldn't there be something like an OSB or plywood to reduce stress on the drywall?
Lioncourt is offline   Reply With Quote
Old 04-27-2012, 11:47 AM   #7
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,010
Default

Insulation Conundrum


Quote:
Originally Posted by Lioncourt View Post
Interesting, I've never heard of a house without some form of sheathing (not just foam) I know the fiberboard isn't much for rigidity but Shouldn't there be something like an OSB or plywood to reduce stress on the drywall?
http://www.buildingscience.com/docum...ting-sheathing

You would need to check with your count to see exactly what they require but it can be done with other bracing methods than complete re-sheeting of the walls.

http://www.finehomebuilding.com/desi...hed-walls.aspx
Windows on Wash is online now   Reply With Quote
Old 04-27-2012, 12:05 PM   #8
Member
 
Join Date: Feb 2012
Location: Utica, NY
Posts: 514
Default

Insulation Conundrum


Correct to the above info. Dense packing Cellulose is much less that fiberglass bats and on top of that it is a better barrier for air infiltration.
framer52 is offline   Reply With Quote
Old 04-27-2012, 12:44 PM   #9
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,010
Default

Insulation Conundrum


Quote:
Originally Posted by framer52 View Post
Correct to the above info. Dense packing Cellulose is much less that fiberglass bats and on top of that it is a better barrier for air infiltration.
Dense packed cellulose is considered and air barrier but the amount of time it will take to do the whole home, and the expense could probably account for the complete stripping of the exterior, sealing, installing batts, and then doing a rigid foam exterior.
Windows on Wash is online now   Reply With Quote
Old 04-27-2012, 05:07 PM   #10
Newbie
 
Join Date: Apr 2012
Posts: 20
Default

Insulation Conundrum


I believe my house already has diagonal braces so this sounds feasible. Doesn't it make siding more difficult since you have to hit the studs and can't rely on the ply substrate? Wouldn't you use the foam sheets as a vapor barrier and tape all of the seams? any other considerations with this whole method?
Lioncourt is offline   Reply With Quote
Old 04-27-2012, 11:42 PM   #11
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,010
Default

Insulation Conundrum


Screw the foam board into the studs and use that are your alignment marks for the siding.

You are getting a bit hung up on the vapor barrier aspect. We don't need one in this climate but you do need a proper air barrier.

Tape and stagger the seams. Foam sections that are larger than the tape can cover.
Windows on Wash is online now   Reply With Quote
Old 04-28-2012, 06:52 AM   #12
Newbie
 
Join Date: Apr 2012
Posts: 20
Default

Insulation Conundrum


Sorry I'm using vapor barrier and air barrier interchangeably
Lioncourt is offline   Reply With Quote
Old 04-28-2012, 08:00 PM   #13
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Default

Insulation Conundrum


1. What type of siding have you decided on?

Check the fasteners on the Celotex fiberboard, many were structural when they first came out. I used it on houses around here in the early '70's, need to use ring-shank nails to get the minimal shear value; http://www.inspectapedia.com/structu..._Sheathing.htm

Check alongside an electrical outlet for fiberglass faced with paper or foil, only R-7-9, worth replacing as WoW said. Leaving it in place will change the exterior sheathing choice....

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 04-28-2012, 08:49 PM   #14
Newbie
 
Join Date: Apr 2012
Posts: 20
Default

Insulation Conundrum


No fiberglass at all. I need to rip some siding off to take a look at whats under. I'm thinking someones vinyl siding, not sure of brand etc yet.
Lioncourt is offline   Reply With Quote
The Following User Says Thank You to Lioncourt For This Useful Post:
Gary in WA (04-28-2012)
Old 04-28-2012, 10:28 PM   #15
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 6,010
Default

Insulation Conundrum


Quote:
Originally Posted by Lioncourt View Post
No fiberglass at all. I need to rip some siding off to take a look at whats under. I'm thinking someones vinyl siding, not sure of brand etc yet.
Alside Prodigy is my favorite in the foam back family of product.

If you put a rigid foam over the exterior, you can just as easily go with a hollow back.

Windows on Wash is online now   Reply With Quote
Reply

Tags
insulation; foam; wall, siding vinyl


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
Attic insulation over old attic floor beffreyj3 Insulation 6 11-18-2011 07:21 AM
Which insulation? Photos attached of room homiefb Insulation 1 08-16-2011 05:44 AM
Garage Insulation yamster Insulation 0 07-01-2011 01:30 PM
Rafter Vents and Insulation nofx1981 Roofing/Siding 15 03-10-2010 08:14 PM
Has anyone used Green Fiber blown in insulation? pomelo Building & Construction 7 02-10-2010 07:17 AM




Top of Page | View New Posts

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