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Author Topic: Expandable foam, yes or no?  (Read 690 times)


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Expandable foam, yes or no?
« on: August 14, 2017, 04:35:08 PM »
  Quick question for you "long time" rv'rs, I recently purchased my first 5th wheel and on my way to my destination, I had a blowout. It tore the belly membrane, the insulation out, and broke the plastic fender. My question is, is expandable foam ok to use to fill in the space where the insulation was before I fix the membrane or should I get replacement insulation? Thanks


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Re: Expandable foam, yes or no?
« Reply #1 on: August 14, 2017, 04:40:27 PM »
I would not use it. There is electrical, gas, water and sewer lines in that area and if you ever need to work on any of these the foam would definitely be a problem.
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Re: Expandable foam, yes or no?
« Reply #2 on: August 14, 2017, 04:52:28 PM »
For a quick - so I can travel - repair, skip the insulation.  Just duct tape the bottom liner and fender to prevent further damage, put a big, decorative Band Aid on it.  Fix it right when you get home or to your destination.

As Tom said, if the foam gets around plumbing and electrical, it can cause headaches if you ever need to get to or trace those components.  If you are simply going under a holding tank or floor with no plumbing or electrical, you would be okay, but remember, IT EXPANDS!
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Re: Expandable foam, yes or no?
« Reply #3 on: August 15, 2017, 02:23:42 AM »
If the area is too large or stressed to trust duct tape, use what the NASCAR teams do:
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Re: Expandable foam, yes or no?
« Reply #4 on: August 15, 2017, 05:28:00 AM »
I would replace the insulation just the way it was and then replace the membrane.
 Expandable foam is only used to  fill the gaps around the pipes that penetrate the floor.

Jack L