knee wall question for finished attic space.

Reply

  #1  
Old 07-13-08, 08:06 PM
Member
Thread Starter
Join Date: Jan 2008
Location: VA
Posts: 330
knee wall question for finished attic space.

Ok, so I just learned what a knee wall is. Please be gentle.

I have a bedroom in a finished attic. I got behind the knee wall and see that the knee wall is insulated.

The home is a cape cod style home built in 1948.

What I don't understand is this:

At the top of the knee wall are the roof rafters. There is a space between the knee wall and the roof of about 4 inches.

This space is completely filled with insulation.

When it is hot out, the knee wall gets pretty warm to the touch and warms the room up.

Is that area (the area between the roof rafters at the top of the knee wall) supposed to be insulated?

I don't see any form of insulation behind the knee wall, but then again, I am very new at this and don't know what to look for.

I am wondering if stopping ventilation between the attic and the area of the knee wall is causing part of the excessive temperatures, or if this area should be completely plugged with insulation?

Thanks
 

Last edited by jj94auto; 07-13-08 at 08:42 PM.
Sponsored Links
  #2  
Old 07-14-08, 07:45 AM
Member
Thread Starter
Join Date: Jan 2008
Location: VA
Posts: 330
Originally Posted by jj94auto View Post
Ok, so I just learned what a knee wall is. Please be gentle.

I have a bedroom in a finished attic. I got behind the knee wall and see that the knee wall is insulated.

The home is a cape cod style home built in 1948.

What I don't understand is this:

At the top of the knee wall are the roof rafters. There is a space between the knee wall and the roof of about 4 inches.

This space is completely filled with insulation.

When it is hot out, the knee wall gets pretty warm to the touch and warms the room up.

Is that area (the area between the roof rafters at the top of the knee wall) supposed to be insulated?

I don't see any form of insulation behind the knee wall, but then again, I am very new at this and don't know what to look for.

I am wondering if stopping ventilation between the attic and the area of the knee wall is causing part of the excessive temperatures, or if this area should be completely plugged with insulation?

Thanks
Please help me with this one...
 
  #3  
Old 07-16-08, 06:08 AM
Member
Thread Starter
Join Date: Jan 2008
Location: VA
Posts: 330
Since no one has answered, I am going to assume that this area should not have insulation stuffed in it.
 
  #4  
Old 07-17-08, 10:16 AM
Member
Join Date: Jan 2008
Location: Greenville, SC
Posts: 15
I wouldn't think you would want to stop ventilation up along the underside of the roof decking between the rafters from the soffit up to the roof peak. I know they make those styrofoam channels that you can put against the underside of the roof deck that prevents blockage of that area for ventilation. Perhaps put those in between the joists above the knee wall, then add insulation on the backside of the kneewall (in the attic) making sure not to block ventilation from the soffitt area. I would think you can use additional styrofoam channels to keep the insulation from blocking ventilation in that area as well.

I'm no expert, so maybe someone could help this guy out. All I know is that blocking this ventilation, if the attic is indeed intended to be vented, is a no no.

Good luck.
 
  #5  
Old 07-18-08, 06:01 AM
Member
Thread Starter
Join Date: Jan 2008
Location: VA
Posts: 330
Originally Posted by OOC-OOC View Post
I wouldn't think you would want to stop ventilation up along the underside of the roof decking between the rafters from the soffit up to the roof peak. I know they make those styrofoam channels that you can put against the underside of the roof deck that prevents blockage of that area for ventilation. Perhaps put those in between the joists above the knee wall, then add insulation on the backside of the kneewall (in the attic) making sure not to block ventilation from the soffitt area. I would think you can use additional styrofoam channels to keep the insulation from blocking ventilation in that area as well.

I'm no expert, so maybe someone could help this guy out. All I know is that blocking this ventilation, if the attic is indeed intended to be vented, is a no no.

Good luck.
Thanks for chiming in!!

Could you please tell me about these styrofoam channels and what they are for?
 
  #6  
Old 07-18-08, 08:06 AM
Member
Join Date: Jan 2008
Location: Greenville, SC
Posts: 15
I found a good picture in this bruchure from a Kansas utility company- see page 4 of the document. I don't know what they are called in the big box stores, but I've seen them aplenty in there. They are pretty cheap. It's the prefabricated truss chute or baffle that is stapled to the under roof decking between the trausses to make sure that insulation doesn't go all the way to the roof deck. These make sure that there is an air channel from the soffit vents to the roof vents. I'm sorry I don't know there exact name of the item. I know in the hardware stores here, they are styrofoam and I think pinkish in color- forgot the brand. Mayber Owens Corning since they're pink.... but don't remember.

http://www.worryfreehome.com/energy_...insulation.pdf
 
  #7  
Old 07-21-08, 08:10 AM
Member
Join Date: Nov 2001
Location: USA
Posts: 1,873
http://www.eere.energy.gov/buildings...rica/26447.pdf

This site will also give you some insights on knee wall insulation, access and ventilation.
 
  #8  
Old 07-28-08, 06:22 PM
Member
Join Date: Jul 2008
Posts: 3
Here's a couple of ideas...

You say when it gets hot your knee wall heats up. Do you have adequate attic ventilation?

Is your roof insulated? If not that may be your problem. Converting any attic space into a room can make for a hot living space if you don't have proper insulation or ventilation.

This website is totally dedicated to do it yourself home insulation tips and advice and maybe you can find some answers:

Itchy's Do It Yourself Home Insulation

Good Luck
 
Reply


Thread Tools
Search this Thread
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 On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 06:25 PM.