I used that 1/8" thick self adhesive, aluminum foil backed, insulation found at Lowes. I then bought a piece of that heavy duty rubber you make shower floors out of and glued/stapled it on to preserve water proofing. Much better than that black woven stuff they use.
Lynn & Diana Wagoner Three Boston Terriers 2011 Chevy 3500HD, DRW, 4X4 2014 Big Country 3650RL Retired
When that happened to me I went to a air cond/heating company and had them cut and bend a sheet metal panel the size I requested and installed that above the tires. So if I ever have another blow out I will not be having to deal with a hole in the slide out flooring. I found there was very little structure there and the metal panel was stronger than what it started out with. Cost was about $20 per side for cut and bent panels. I used a good caulk and non rusting screws to secure the new panel up into place. So far over about 6-7 years that has worked perfectly.
Stacey Frank 2016 Tiffin Allegro Bus 40AP 2019 Tesla Model X 2015 Cadillac SRX we Tow 1991 Avanti Convertible
I did see someone put rubber matting glued into their wheelwell to prevent damage.. above that.. wedges of foam with spray foam between? Or get really technical and figure out the arc, and cut foam pieces to fit and glue them all together?
Mike 2012 Winnebago Impulse Silver 26QP 2005 16.6 Double Eagle 2018 Jeep Wrangler JK previously Snowbird Campers, Triple E Motorhome and Fifth Wheel