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 01-06-2012, 11:47 AM   #1
Newbie
 
Join Date: Dec 2011
Location: New Hampshire
Posts: 13
Rewards Points: 10
Default

Insulating a valley


I have an exposed valley in the master bath about (5 square feet) that I need to insulate what would be the best way? There are 4 rafter bays in this the ends are not open to soffit vents. Also this is on the north side of house so no sun to heat up the roof. Cold climate area.
Thanks

altann is offline   Reply With Quote
Old 01-06-2012, 11:58 AM   #2
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,500
Rewards Points: 4,116
Default

Insulating a valley


Not sure what your really asking. Since a valley is on the roof what does that have to do with insulating the ceiling in that area?
In that small an area it should be fine if there's no soffit vents as long as the rest of the roof is vented properly.

joecaption is online now   Reply With Quote
Old 01-06-2012, 12:08 PM   #3
Newbie
 
Join Date: Dec 2011
Location: New Hampshire
Posts: 13
Rewards Points: 10
Default

Insulating a valley


Ten foot ceilings in bathroom and in one corner the valley is exposed running up through to attic.
Thanks
altann is offline   Reply With Quote
Old 01-06-2012, 12:09 PM   #4
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,500
Rewards Points: 4,116
Default

Insulating a valley


A picture may help on this one.
joecaption is online now   Reply With Quote
Old 01-06-2012, 01:12 PM   #5
Shut in w/o Home
 
seeyou's Avatar
 
Join Date: Dec 2008
Location: Lexington, KY
Posts: 696
Rewards Points: 500
Default

Insulating a valley


Quote:
Originally Posted by joecaption View Post
A picture may help on this one.

He's got a vaulted ceiling with a valley in it.

I'd say closed cell foam would be the best bet. Is the ceiling down?
seeyou is offline   Reply With Quote
The Following User Says Thank You to seeyou For This Useful Post:
jmiller (01-07-2012)
Old 01-06-2012, 01:23 PM   #6
Newbie
 
Join Date: Dec 2011
Location: New Hampshire
Posts: 13
Rewards Points: 10
Default

Insulating a valley


Valley is in corner over bathtub 10 foot ceilings through out. I was wondering if I was to use pink fiberglass should proper vents be put in just to keep insulation away from underside of roof plywood? Attic is well vented other than valley areas. Also 2x10 rafters


Thanks
altann is offline   Reply With Quote
Old 01-06-2012, 05:20 PM   #7
Member
 
Join Date: Jan 2012
Posts: 37
Rewards Points: 25
Default

Insulating a valley


Yes, keep insulation from touching underside of roof sheathing. I don't think you need to worry about ventilation. It sounds like its a small area not ending at cornice or ridge.
As a builder I am supposed to tell you that you need R38 insulation. I don't know if 2x10s will work. You may have to fur down.
BTW Why are you having to do this? Why didn't the builder do it? Are you aware of all the sealing and insulation requirements?
glkirk is offline   Reply With Quote
Old 01-07-2012, 10:23 AM   #8
Member
 
Join Date: Nov 2010
Location: Indianapolis
Posts: 84
Rewards Points: 75
Default

Insulating a valley


Quote:
Originally Posted by glkirk View Post
Yes, keep insulation from touching underside of roof sheathing. I don't think you need to worry about ventilation. It sounds like its a small area not ending at cornice or ridge.
As a builder I am supposed to tell you that you need R38 insulation. I don't know if 2x10s will work. You may have to fur down.
As a builder you should also know that IRC code requires ventilation, and there is no exception for being a small area or not ending at the eave/ridge. r806.1 http://publicecodes.citation.com/icod/irc/2012/icod_irc_2012_8_sec006.htm

A cathedral valley (yes I made that up) over a bathroom on the N side in a cold climate == ice damming.

CC spray foam applied directly to the underside of the roof sheathing would be the best solution, partly because it's one of the few options you have, but also because it is the best guarantee (IMO) that none of the warm humid air from the bathroom will get to the underside of the roof sheathing to melt accumulated snow and cause ice.
http://publicecodes.citation.com/icod/irc/2012/icod_irc_2012_8_sec006_par004.htm

My only concern would be that valleys tend to be one of the most leak prone areas of the house, and a leak could go unnoticed for longer due to the foam.
jmiller is offline   Reply With Quote
The Following 3 Users Say Thank You to jmiller For This Useful Post:
mae-ling (01-08-2012), seeyou (01-07-2012), Windows on Wash (01-08-2012)
Old 01-24-2012, 09:40 AM   #9
Newbie
 
Join Date: Dec 2011
Location: New Hampshire
Posts: 13
Rewards Points: 10
Default

Insulating a valley


This area of valley is about 25 square feet. I'm looking into spray foam sprayed on the underside of roof plywood. There are no soffit vent in this area because of valley. Only 4 rafter bays 4 feet long until they reach attic space. If I spray foam this area should I back it up with fiberglass insulation to meet sheetrock or fill the 2x10 rafter bays with spray foam? Also before sheetrock should a plastic vaper barrier be installed? And blocking where rafters meet cold attic?

Thanks

altann 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
Help with tricky valley wombosi Roofing/Siding 34 11-11-2011 09:22 AM
Need input on this open valley technique jogr Roofing/Siding 12 11-01-2011 07:49 AM
I&W around pipes and valley metal fastening diyroofer Roofing/Siding 0 09-12-2011 06:39 PM
Insulating basement ceiling - your recommendations? jtmann HVAC 8 11-24-2009 05:44 PM
Insulating brick above & close to grade Peter Shepherd Building & Construction 1 09-16-2009 07:41 AM




Top of Page | View New Posts

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