Wednesday, October 5, 2022


Ask Dave: Can my RV have soft floors even without a water leak?

Dear Dave,
Can soft spots develop on the floor of my 5th wheel trailer without being caused by water damage? We have a 2017 Primetime Crusader Lite, model 30BH. The soft spots started 2 years after we bought it new, mainly at high traffic areas. No signs of water anywhere in the rig. Had the rig checked for exterior and plumbing leaks but none found. When I removed a floor register, I noticed the actual laminated wooden part of the floor was maybe 5/16″ thick, definitely less than 3/8″. Couldn’t see how far apart the joists were. There’s about 1 1/2″ to 2″ of high density foam underneath the flooring. Anyway, is it possible to have delamination and/or soft spots without any water damage? Thank you very much! —Tom L.

Dear Tom,
Yes, there are several things that can cause a soft floor, including delamination and a breakdown of the block foam insulation.

First, let’s take a look at how the traditional trailer floor is constructed. Like most Forest River products, they do not show construction in the brochure, rather pictures of glitzy stuff like a fireplace and the kitchen faucet.

Here is an exploded view of a Winnebago floor from one of their brochures.

Most trailers start with a welded steel frame and I would assume your FR was purchased from Lippert or another Original Equipment Manufacturer (OEM) in Elkhart. The floor has a underlayment fabric, thin luaun wood sheet, block foam insulation with some wood framework around the perimeter and sparingly through the middle, and then the upper paneling which you indicated was less than 3/8”. These are all laminated with an adhesive and vacuum sealed and FR calls it Eternabond construction. Most manufacturers used ½” or thicker upper flooring for rigidity, so yours could just be the thinner material breaking down and feeling soft. Another item that happens is the adhesive loosens, which is called delamination. So there is a separation between layers, again feeling soft.

One other issue I have found is the block foam breaks down and becomes soft as there is little or no framework in high traffic areas. About the only thing you can do is peel back the carpet or flooring and inspect the wood. Maybe even cut out the wood area that feels soft and check out the insulation. In several soft floor cases we have cut out the wood, pulled out the insulation, and built a “ladder” made of 2x4s to lay down in the high traffic area, then fill the holes with insulation. If the upper wood flooring was soft, we would replace that with StructureWood and use the ladder as framing to support the upper wood flooring.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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10 days ago

welll, maybe we’ll wait untill RV builders will feature HD models for us fat people…
there are bariatric beds-600-1000 lb cap…

15 days ago

I agree with Spike, Most RV’s are junk and made very sloppy and cheap.

Bob M
7 months ago

I was in brand new travel trailers yesterday at the CNY RV show and noticed two travel trailers that had spongy spots on the floor. Don’t remember the brand. Some RV companies are terrible at showing in brochures and on the internet what materials are used to construct their RV’s

7 months ago

I’ve seen floors delaminate, not in motor homes but brick & motor homes! I did remodeling for about 15 years & had a customer that her 20 year old unit kitchen floor felt weird! When I got it apart the 5/8″ plywood was delaminating! seems that the ply was installed on 24″ centers rather that the normal 16″ centers! That caused the ply to flex & eventually come apart.It cost a lot of money to re-build that floor. The really bad part there were 15 more units that are going to have the same issue.
As far as what Dave said about “StructureWood” there are several different types & brands & all of them not equal. Just depends mostly on the quality of the glue & procedure when manufactured! I know that when building a RV, they are very concerned about weight.

Tom Hosack
7 months ago

Here’s a good vid showing the fix. I had a 2013 Jayco Ultralite that had this issue in a couple of high traffic areas. Traded it in before it before in got too bad.

7 months ago

I have the foam floor in my unit. It is a disgrace to the art of engineering. Is going to fail one way or another. Imagine building a house with styrofoam blocks for a foundation. I know the argument is about the weight but this floor construction method will fail in time.

7 months ago

Several years ago I was at an RV show and my mother-in-law, who is not at all large, was walking around in a Heartland 5th wheel. The floor was like a trampoline, giving significantly underfoot. So, even insufficiently built showroom units can have soft floors that I imagine only get worse with time.

My goodness…what designer/engineer in their right mind thinks FOAM is a good long-term structural support to replace 16″ O.C. joists covered by minimum 1/2″ plywood for a floor! Two reasons come to mind: 1) Cheap to produce; 2) Weight reduction. Both at the cost of quality and long term durability.

This is one of the reasons I continue to say that many of today’s RV’s are junk. Look under the covers of the glitz and the “build” is substandard.

Last edited 7 months ago by Spike
Gordy B
7 months ago
Reply to  Spike

I built houses on and off for over 50 years, the only time we use luaun on floors was to make a smooth base for tile or linoleum. The floor described is only good enough to get it out of warranty. The foam will definitely break down in high traffic areas. with only luaun as a a base because it is too thin, and the 5/16 plywood will only hold as long as the foam supports it. If the unit was mine, I would remove the floor covering in all the traffic areas and add a 1/2 inch of plywood before the existing floor breaks down any more. You may want to trim a little off the bottom of the doors or a few drawers, but the floor will give you more years of service. A bit of unsolicited advice if you are shopping for a unit, find out how the floor is constructed before signing on the dotted line. The floor is the foundation of your unit, it has to be solid to last. If you plan to full-time it is critical!! HAPPY TRAILS