DIY Chatroom -  DIY Home Improvement Forum
    DIY Forum     DIY Blogs     Photos     Woodworking     Advertise     Contact Us  

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!
Go Back   DIY Chatroom - DIY Home Improvement Forum > Home Improvement > Insulation

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-22-2011, 11:00 AM   #1
Newbie
 
Join Date: Mar 2008
Posts: 21
Default

Adding attic insulation


I'd like to add some insulation to my attic. I just had the house sided and re-roofed, so I now have a vented soffit and ridge vent. I know I will need to put in some rafter shutes, baffles or whatever you want to call them in between the rafters. I presently have about 7 inches of blown in insulation on my attic floor which is under the reccomended amount for S.Eastern Pa. So my question is this , Can I use unfaced batts on top of the blown in insulation running them perpendicular to the joists, or do I need to use more of the blown in insulation? Thanks.

rakuz66 is offline   Reply With Quote
Join DIYChatroom.com

Join the #1 DIY Forum Today - It's Totally Free!

DIYChatroom.com - Are you about to start a new home improvement task and need some help? Do you need advise on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that DIY Chatroom is a great community to join. Best of all it's totally free.

Join DIYChatroom.com - Click Here
JOIN FOR FREE


Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. DIYChatroom.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any home improvement task!
Old 07-22-2011, 01:54 PM   #2
Member
 
Join Date: Jan 2010
Location: Pennsylvania
Posts: 523
Default

Adding attic insulation


You can use the batts. That's a great way of mitigating the thermal bridging caused by the joists. While you're up there, you might want to check the existing insulation for dirty spots, which would indicate air intrusion. Seal up any gaps.

operagost is offline   Reply With Quote
Old 07-22-2011, 02:12 PM   #3
Architectural Designer
 
AGWhitehouse's Avatar
 
Join Date: Jul 2011
Location: Connecticut
Posts: 1,363
Default

Adding attic insulation


While your crawling around adding the chutes and batts, add a tyvek air barrier on top of everything as well. Air movement within fiberglass batts greatly reduces the effectiveness. So if you put an R-30 batt up there without an air barrier, then you only really be getting an R-20, or so gain, as the top layer of batts will be compromised do to attic air movements. So, for the $150 or so that a tyvek roll costs, you'll reclaim that lost R-10 or so.
__________________
Life's too short...so enjoy it!

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
AGWhitehouse is offline   Reply With Quote
Old 07-22-2011, 02:18 PM   #4
Member
 
Join Date: Jan 2010
Location: Pennsylvania
Posts: 523
Default

Adding attic insulation


Does the Tyvek block moisture? That would be bad.
operagost is offline   Reply With Quote
Old 07-22-2011, 06:02 PM   #5
Moderator
 
Join Date: Mar 2009
Posts: 8,770
Default

Adding attic insulation


If blow-in fiberglass, yes that will reduce the R-value, by compressing the existing. If blow-in cellulose, just use more, it will also stop any convective loops in your blow-in f.g.: The "biggest loser" in fiberglass insulation....

Tyvek (58 perms) won't block moisture, (I've repeatedly sited that) compared to Typar (16 perms), which will. Moisture movement optimum is 18-32 perms....

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
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
Attic project - Would like opinions whataboutj Insulation 6 06-29-2011 04:07 PM
Adding Insulation - getting around in attic VelvetFoot Building & Construction 2 11-13-2009 02:49 PM
Adding insulation to only a portion of an attic? curls00 Building & Construction 22 10-27-2008 10:41 AM
attic insulation question dderolph Building & Construction 10 11-03-2007 06:21 PM
Proper Attic Insulation reikiray Roofing 5 08-04-2007 11:59 AM


Top of Page | View New Posts


All times are GMT -4. The time now is 03:45 AM.


© 2003 - 2010 The Building Network LLC