Go Back  DoItYourself.com Community Forums > Interior Improvement Center > Insulation, Radiant and Vapor Barriers
Reload this Page >

Replace Basement Joist Fiberglass Insulation with Foam Boards

Replace Basement Joist Fiberglass Insulation with Foam Boards

Reply

  #1  
Old 04-04-19, 08:47 AM
M
Member
Thread Starter
Join Date: Jul 2016
Posts: 23
Received 0 Votes on 0 Posts
Replace Basement Joist Fiberglass Insulation with Foam Boards

Good Afternoon all,

I have hopefully three quick questions.

First a little on what I am looking to do:

I am currently beginning a project to finish my basement. One of the items I want to take care of while I am doing this is to replace the fiberglass insulation in the Joists. There were quite a few pests in the past and its in bad shape. What I was curious about was is it possible to replace the fiberglass with the foam insulation boards as they are more pest resistant.I know that the foam boards require a ignition barrier.... So
questions are as follows.

1) Would placing a 5/8 inch sheet of sheet rock over the foam board in between the joists be sufficient as an ignition barrier?
2) Is there any issue you all can see that would make that a bad plan?
3) Is there a better material I can install myself other then the foam boards or fiber glass that would insulate and be pest resistant?

Regards,
Masoric
 
  #2  
Old 04-04-19, 09:44 AM
2
Member
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 1,099
Received 80 Votes on 68 Posts
If you are going to finish the basement you should provide heating/cooling.

If that space is heated/cooled you do not need insulation between it and the finished space above.

You can get foam insulation board that has ignition-proof facing.

Drywall below foam board would also provide the required ignition protection.
 
  #3  
Old 04-05-19, 03:01 PM
M
Member
Thread Starter
Join Date: Jul 2016
Posts: 23
Received 0 Votes on 0 Posts
Thank you... for the response. The way the basement is constructed the joists sit on top of the poured concrete wall. The 8 inches of space on top of the concrete only has plywood, wrap and siding between the outside world and the basement so I feel that it is necessary to have something in there even if I finish the basement. I did not realize that you could foam insulation with ignition-proof facing. I will look into that.

Thank you again.
 
  #4  
Old 04-05-19, 03:20 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 26,807
Received 852 Votes on 780 Posts
It makes sense to do your rim with at least 2" of rigid foam. Only reason to insulate the rest is for sound dampening. The insulation you want is called Thermax if you don't want the extra work of covering it.
 
 

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