Blown in through top of wall?


  #1  
Old 03-06-08, 10:49 AM
H
Member
Thread Starter
Join Date: Mar 2008
Location: Winnipeg, Manitoba
Posts: 9
Upvotes: 0
Received 0 Upvotes on 0 Posts
Blown in through top of wall?

I've heard that if there is access to a top of a wall, (as one might have in a 1 1/2 story house) cellulose can be blown in through the top. The question this raises with me is if holes are drilled in the top plate of a wall every 16" to facilitate the installation of the cellulose, won't this seriously compromise the structure of the wall?
I appreciate any input.

Glenn,
Winnipeg
 
  #2  
Old 03-06-08, 11:08 AM
D
Member
Join Date: Sep 2005
Location: ohio
Posts: 193
Upvotes: 0
Received 0 Upvotes on 0 Posts
As far as I know there is usually no load on an exposed top plate. At any rate the holes needed to blow in are only 2 inches diameter. If you do it make sure to use a fill tube and not just a nozzle to avoid settling.
 
  #3  
Old 03-06-08, 02:39 PM
M
Member
Join Date: Feb 2008
Posts: 77
Upvotes: 0
Received 0 Upvotes on 0 Posts
"thar she blows"

Make sure that there are no firestops or obstructions to keep the insulation from going down. We typically blew cavities using two holes per cavity that would really pack it in. I am not sure about down from the top.

You can blow it in until you get resistance. By using a hand timer you can see how long it is taking. If it fills too fast you know you have some blockage. Also you can take a fish sinker weight on a mono-filament line to make sure that the cavities are open.

Remember that blowing will find any opening including some electrical box fixtures or any opening such as spaces around plumbing.

Jim
 
  #4  
Old 03-06-08, 03:48 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Posts: 27,061
Received 1,910 Upvotes on 1,716 Posts
The blowers I have used only require a hole that is 1 1/8" or so. If you make holes through the top plate to insulate, when you are done insulating, the holes would best be filled with a fire-rated sealant such as Great Stuff Pro- gaps and cracks- fire rated foam.

Some area require all top plate penetrations to be sealed in this manner to slow the spread of a fire.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: