How to add a missing back panel through the inside of a cabinet

Question

I have an open gap in the back of my kitchen cabinet drawer area that I want to seal up with a panel since there is a musty draft from the exposed old masonry back there. I also want to keep rodents out. I have some thin wood panels that I can cut up to put back there but I don't know how I would attach it since I would not be able to get to it from behind and only can push it up through the cavity.

It's also hard to get a larger piece of wood back there since the rails go almost to the back and there isn't a lot of room to maneuver.

Should I cut an 1/8" thick panel of wood exactly to size, bend it in there somehow and then attach it with something - maybe some sort of thing that lets me nail it into the side somehow?

I'm tempted to just use some thin foam - but not sure how resistant that would be to rodents.

Answer 1

Small angle/corner/L brackets should work.

Make the panel about 1/8 inch less than the width of the inside of the cabinet(will need to check, just guessing here).

Screw the panel to the brackets with the other end facing the front.

Push the panel to the back and then can screw the brackets to the sides.

Caulking should seal the openings.