Chair rail insulation

[Olympia_Lowlife]

Hey I’ve been looking through threads all morning and can’t find an answer. Has anyone successfully been able to get 2” XPS foam board stuffed into the cavity behind chair rail? I’m not really sure what to do if I can’t get it to fit. I’m doing 2 inch floor insulation and 4 inch total for walls and ceiling anyways thanks for your time

[HazMatt]

What's your space constraint behind the rail?
Might do well to put multiple plys of 1/2" board.
(It will be very helpful if you populate the fields in your profile, so we all know what sort of bus you're working with...)

[Olympia_Lowlife]

Hey I went and updated my profile but it is a 2002 Thomas MVP 84 passenger and I think the space was just shy of 2 inches I didn’t know if people liked to shave down 2 inch a bit or put smaller and spray foam around it or something

[o1marc]

2" won't fit in the cavity. I use 1/2" piece of Polyiso, foil outside, and then back that with 1" rigid pink.

[family wagon]

Have a look down the slot to see why the board won't go in. Are there rivets or other features blocking the way? Is the board simply too thick?


Pourable foam is an option you might consider.

[o1marc]

Originally Posted by family wagon

Have a look down the slot to see why the board won't go in. Are there rivets or other features blocking the way? Is the board simply too thick?


Pourable foam is an option you might consider.

The hat channels are only 1-1/2" , 2" will not fit.