Insulation Question - 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 11-24-2012, 09:54 PM   #1
Newbie
 
Join Date: Nov 2012
Posts: 2
Rewards Points: 10
Default

Insulation question


Hi, everyone - first post for me so I'll try to make it quick! We are moving to a new home - attic has a 3/4" plywood floor with (I assume but have not been able to check) insulation underneath. Inspector gave it a roughly R24 rating. We would like to add to this. From a moisture standpoint, can I just roll out some R30-something insulation right over the plywood or would the plywood need to be removed? Paper-faced for a vapor barrier or unfaced? Thanks in advance!

Advertisement

tjniemann is offline   Reply With Quote
Old 11-24-2012, 10:36 PM   #2
Member
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 8,376
Rewards Points: 3,546
Blog Entries: 4
Default

Insulation question


right over the plywood should be fine. The vapour barrier needs to be at the ceiling level. Unfaced. You do not want two vapour barriers.

Advertisement

__________________
Do not PM with questions that can be asked in a forum. I will not respond.
joed is online now   Reply With Quote
Old 11-25-2012, 12:21 AM   #3
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Rewards Points: 1,000
Default

Insulation question


Do any air sealing you can while anything might be exposed; around elect wires, pipes, ducts, etc. Spray foam and/or caulking should work well. Cellulose blown over the whole area will do much better than FG batts.
jklingel is offline   Reply With Quote
Old 11-26-2012, 08:06 PM   #4
Newbie
 
Join Date: Nov 2012
Posts: 2
Rewards Points: 10
Default

Insulation question


Appreciate the replies. Specifically, why would the blown work better than the rolled?
tjniemann is offline   Reply With Quote
Old 11-26-2012, 08:12 PM   #5
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Rewards Points: 1,000
Default

Insulation question


blown cellulose will fill all voids and will slow down air movement better than fg. it also "crusts over" to further limit air movement through it.
jklingel is offline   Reply With Quote
Old 11-27-2012, 10:05 AM   #6
ink
DIY Enthusiast
 
ink's Avatar
 
Join Date: Jan 2010
Location: Maryland
Posts: 114
Rewards Points: 75
Default

Insulation question


Where do you live? Local climate will change your vapor barrier needs.
__________________
inK

Hammer in Hand, Dad on Speed Dial
http://www.mydadsshoes.com
ink is offline   Reply With Quote
The Following User Says Thank You to ink For This Useful Post:
Gary in WA (11-27-2012)
Old 11-28-2012, 06:57 PM   #7
Registered User
 
Join Date: Mar 2009
Posts: 9,993
Rewards Points: 2,052
Default

Insulation question


The plywood is a vapor retarder. Any (1/8") gaps under the plywood will effective allow moving air to rob you of insulation R-value added on top the sheathing. Still air has R-1 for 1-4". You may grow mold under the sheathing, check annually, with insulation on top.

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
Fixing multiple attic electrical issues before blowing in insulation darlingm Electrical 11 11-19-2011 10:19 AM
Another cape insulation question exiledgator Building & Construction 21 10-14-2011 09:42 PM
Garage insulation question trojanman1 Building & Construction 7 09-16-2009 03:51 PM
rafter insulation question Jeremy Hillary Boob, PhD Building & Construction 7 08-02-2009 09:19 AM
Insulation Question skavang13 Building & Construction 3 11-16-2008 06:08 PM




Top of Page | View New Posts