Heat from cat. converter damaging my floor

[Thor2014]

Hey all. I'm wondering if anyone has had this problem, and what you did about it. I have a 2014 22 ft Thor Freedom Elite Class C motor home. The heat from my catalytic converter has melted my underbelly, and now the bottom layer of floor is really soft and causing soft spots when we walk inside the RV. Campers Inn quoted us around $10,000 to redo the entire floor, or for $2500 they could put a couple of metal support braces under the wood and add more underbelly to prevent further damage. I am wondering if there is a DIY fix I can do myself. I have easy access from under the camper, so I'm wondering if I can just cut out the bad wood and replace it? Or can I nail a piece of OSB over it for extra support? I plan on adding a thermal heat wrap and maybe spraying the existing heat shield with some hi temp silicone coating to protect the floor from further damage. Liquid wood stabilizer would be the perfect solution to restore the wood, except it is very flammable and I don't think I can use it because it gets so hot near the cat. I would appreciate any advice I could get on how to resolve this issue. Thanks!

[Bill Johnson]

Hard to tell by the photo angle but it looks like your heat shield is off to the side a little. You might be able to screw a piece of sheet metal across the two heat shields

[Thor2014]

You’re right, it is off to the side and not completely covering the exhaust system, which is why I guess this happened. I do plan on using sheet metal to ultimately solve the issue, but I also need to figure out how to repair the floor as well. Thanks.

[RACarvalho]

On our rig I noticed the floor, on the inside, would get really hot where we have the cat so I applied the below to the floor just above the cat.
It solved the problem.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Bill Johnson]

Originally Posted by Thor2014

You’re right, it is off to the side and not completely covering the exhaust system, which is why I guess this happened. I do plan on using sheet metal to ultimately solve the issue, but I also need to figure out how to repair the floor as well. Thanks.

Is it possible your catalytic converter can be loosened and turned so the heat shield is facing up. A person said they put a heat shield above on the bottom of the floor but Butyl tape can withstand temperatures up to 300 degrees Fahrenheit. I know it has that what looks like foil on it, but being exposed to this kind of heat that would burn a wood product In your case might start a fire. The original heat shield might only need a small piece of metal screwed to it to cover that left side

[Beau388]

I would spray the entire area with Lizard Skin Ceramic and then top coat it. I have done several of my cars and truck in the sprays and really like the results. It works muck better than the typical undercoat to stop rust, add insulation and noise control.
<https://lizardskin.com/>

[Mousemate]

Have you had the cat looked at to see if its bad...or if you are getting to much raw fuel into it and it is overheating to burn it off?

[Bill Johnson]

Originally Posted by Mousemate

Have you had the cat looked at to see if its bad...or if you are getting to much raw fuel into it and it is overheating to burn it off?

Walker mufflers says under load they can reach 1200 degrees, just right to Barbecue the floor of a motorhome without a heat shield

[Lt Keefer]

Originally Posted by Mousemate

Have you had the cat looked at to see if its bad...or if you are getting to much raw fuel into it and it is overheating to burn it off?

How many miles on the coach? Being a 2014, you could have a plugged cat, I would have it looked into.

[dkoldman]

Find a unsecure storage facility. Park it there and wait while you think of next steps.

[Bill Johnson]

Originally Posted by Lt Keefer

How many miles on the coach? Being a 2014, you could have a plugged cat, I would have it looked into.

Wouldn't his check engine light be on, if it's plugged his power would be down to nothing

[Thor2014]

7000 miles

[JimOIB]

Originally Posted by Thor2014

7000 miles

I don’t know what I’m looking at. Is that the floor after CW cut back the plastic barrier? The small black rectangle in the first pix is the damage? Or has that all been melted?

I’ll get under my coach on Monday and take a picture of the heat shields so you can compare.

As to your original question - I had water damage on the inside floor and found a grid work of metal cross beams that the floor is glued to - no fasteners of any kind. I cut out the floor and installed a new piece of plywood so it overlapped 1/2 of the cross beams. Used countersunk self tappers. The floor was 3/8 inch thick and plywood not OSB. Not sure about the underside.

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[JimOIB]

Sorry about the delay - didn’t back in town until last night. I have the same chassis as you but a few years newer. I can not see the floor of my coach due to the wide heat shield above the cat. In your pics it looks like half of the heat shield is missing or it has shifted. Just a data point for you - seems like the dealer would have noticed this. Heat shield issue needs to be resolved or any floor repair is for naught.

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[RC Osborne]

I purchased aluminum sheets at Lowes or Home Depot and then bolted them to the frame for a better heat shield. My hydraulic lines were too close and were bubbling. It worked great. On our dog house I Dynamat material and it helped with heat transfer and noise into the cab area. You might consider that as well.