Spongy floor repair

[neil]

Sent: 11/25/2002

I have a flooring problem in a 1983  26.5 ft. Winnebago. The floor is an insulated sandwich panel. The floor has de-laminated and has spongy areas. Are there any easy fixes?

[HAL]

Sent: 11/27/2002

HAL HERE. BY MY BOOK FOR 79 IT SAY'S TO:

   
• PULL BACK THE CARPETING IN THE PROBLEM AREA AND MARK THE EFFECTED FLOOR SURFACE.
• WITH A CIRCULAR SAW,REMOVE THE TOP LAYER OF PLYWOOD AT THE MARKED FLOOR SURFACE AREA
• CUT  OUT THE DAMAGED STYROFOAM CORE MATERIAL AS REQUIRED.  NOTE: MAKE STRAIGHT LINE CUTS WITH 90* CORNERS IF POSSIBLE.
• CUT NEW SECTION OF STYROFOAM AND PLYWOOD TO THE EXACT SIZE OF THE CUT-OUT    AREA. GLUE INTO PLACE.
• IT IS RECOMMENDED THAT A 1/2" BEAD OF SCHNEE-MOOREHEAD 5522 SEALING COMPOUND BE APPLIED ALONG THE PLYWOOD SEAM OF THE REPAIRED SURFACE.

[Alaska Gal]

Sent: 1/2/2002 1:02 PM

I'm in the process of doing my 1966 winnies floor I was advised to use what they call green plywood, 1/2" and on top place a board called underlayment board. 1/4" two boards equal 3/4" board for floor using 3"screws, also was told to use a sealer on 2x4's in floor (keeps squeaks out) back side of underlayment board spread a water proof glue lay on top plywood.. good luck .. My first time .. ak gal

[Alan]

Sent: 1/5/2002

I have a 1976 that the floor also felt spongy in several places. I took out the carpet , and removed the dinette. Got 2 sheets of 3/4 plywood. We placed the plywood down with drywall screws (countersunk). sparkled the screw heads and sealed the plywood. put down some new indoor/outdoor blue/gray carpet and replaced the dinette with a flex steel jack-knife sofa (Just fit). The floor is firm. No soft spots. The sofa gave us a little more room.

Alan

[WoodCoDogs]

Sent: 5/25/2008 2:30 PM

I also have an older Chieftain that has a soft floor in the center of the flooring where you walk/stand in the kitchen area...I am wondering if I should just lay down a sheet of OSB screwed to the good part of the floor and put carpet over that?...Or should I go ahead and make it a real project and remove the soft spot in the floor?...Or do I have to completely gut the Winnie and replace the entire floor?...Any advise?

[Oz]

Sent: 5/25/2008

I have a spot just like that too and I'm interested in finding out as well.  It seems to me that, if you just cut out the affected area and glue in a replacement piece, if there isn't anything underneath to support it, what would keep your foot from going right through when you step on it?   I never had the sub floor up so I don't know "what lies beneath".

[Slantsixness]

Sent: 5/25/2008


Well...

Let's see....

No. To repair a soft area, you don't have to replace the entire floor. But... you will have to "gut" (remove) the cabinetry in order to do it right....

If you have an area... lets say the kitchen/ dinette floor area that is soft, (which is common)

Simply remove the dinette, and the kitchen cabinets. This may sound obnoxiously severe or complicated, but it's not. just a series of screws to the floor, walls etc. You can have all this out in  matter of a couple hours (or sooner if you're renovating these items...)
expose the floor. remove the carpet or vinyl, or combination of layers that became what is your floor today...

The main Winnie floor (the original floor) is a thermo panel... kind of... it's like a thermo panel wall, but, with 1/2" plywood on one side, and ist's about 1" thick... maybe 1 and a 1/2...

Anyway. remove the effected soft area. the damage, no matter how extensive will be obvious.   the floor is made up of several panels, much like the roof is. the panels are held up by the chassis frame. You can slice in a section, no matter how large, provided your repair spans the frame width wise. The original floor out to the edge of the motor home does not need to be replaced to remain strong. The replacement sandwich, Whether it's a thermo panel-like design, or simply multiple plywood layers, needs to be secured to the frame, and glued with a suitable waterproof adhesive to the original flooring. It's a little tricky until you see what you have to do with your own eyes..

Repairing a soft area is simple... sort of... but structurally, just replacing the Plywood and foam and gluing it back together as Winnebago says to do in the service manual is not rigid enough. Keep in mind, the repair manual is talking about a rig that would still be relatively new, so a soft spot or damaged area would be quite small... and that's probably not what is happening with rigs that are 30+ years old.. (think years of exposure to weight, moisture, spills, pet accidents, other accidents.. etc... once the upper wood layer is unsound, the problem will continue to get worse, and the foam underneath will continue to deteriorate too, in more than just the seemingly "soft" area.)

But a word of caution:
removal of the entire floor is a gigantic job. you would actually have to lift the walls off the floor to do that, or else face structural instability of the rig, or huge amounts of additional supports welded  to the existing Chassis frame.

These rigs were built (and still are, except for the ones made from Tour bus chassis...) from the frame up... meaning:
roof -- then it's Done!

Repairing an area of the floor that encroaches over the frame, or all the way to the sidewall, should have additional support framing added to the chassis frame (to have something to attach to!). This an be as simple as a 1X1 wood box frame secured to the chassis, or as elaborate as a welded steel sub frame... both would hold up quite well.

As you might have noticed a time or two, some winnies seem to have sags in the exterior walls, around the front, or behind the rear wheels. This is a sign of a failed or failing floor structure, and  it's not easy to fix when it's visibly noticeable from the exterior. taking care of the floor structure in a winnie is pretty important, since the floor holds up the entire coach.
Don't just let the soft spots "go" no matter how small... fix them!

Tom 

[labbie1]

Anyway, thinking that I might have to replace some of the floor, have a few soft spots that need attention.  Will be replacing that with either 3/4" or 1" plywood. 

[hose-man]

option to consider re: the floor soft spots.    Rather than tear up the floor, I added support for the soft spots from the underside.      The driveline lies more or less right below the walkway, which is where my soft spots were.    It was easy to work above the drive line, welding square tube between the factory cross beams to support the softspots in the floor.

The only caution I have is that the build up of oil & tranny fluid under your rig is flammable, which can make for an exciting moment or two while welding up cross bracing.    Not that I'd know anything about that........ W%

[labbie1]

I am not certain that there really is going to be much more to the floor than a couple of patches.  We only have one real soft spot and it isn't any larger than 6"x6" (if that).  The spot is actually developing into a small hole whose edges seem to crumble when you happen to step on it. The issue is the PO glued the carpeting to the subfloor with a substance only the almighty himself can remove .  If it wasn't for the glue on the carpet the fix would be easy. Unscrew the threshold about an inch away, roll back the carpeting, patch the spot and put everything back just the way it was. Since it is going to require tearing up the carpet to fix and I have been battling with dog hair removal from the carpeting it was decided to replace the floor covering to something more doggie freindly.
While I will certainly be around to help with this project Glenn is handling the "fixing" and I leave the end decision in his trusty researching fingers.
There is always the chance, as there is with all winnie projects once you've stripped away the carpeting this simple fix may be far more extensive than we ever imagined. Don't worry though we'll take things as they come, a lesson learned from fixing up a 100 y/o house.

[JDxeper]

You might look at a product like this to "shore up"  the soft spots.
http://www.jamestowndistributors.com/userportal/show_product.do?pid=1269&familyName=Smiths+Cold+CPES+Epoxy

JD
Note, you may be able to find a similar product that is less expensive.  Google it.
http://www.boatersworld.com/product/MP81121009.htm?utm_medium=productsearch&utm_source=google

[Froggy1936]

This  may or may not be what you want to hear. I replaced the floor in the bathroom due to major weater damage and rot at base of toilet. all turned out well. Then i had asoft spot at the entrance area. So i figured i would find the same thing. After cutting out a large area of original floor (that BTW did not show any water damage) I removedall the 1 in thick styerfoam insulation which had been compressed to 3/4 in below that is the steel panel that covers the entire area that the whole body sits on I installed new styerfoam and new plywood & added a 2inx2in oak board on top of the frame under the steel pan  recovered the entire floor, A nd it still feels exactly the same as it did before. What i reccomend is to ignore the soft feeling and spend your time elsewhere -  Frank 

[ClydesdaleKevin]

We have a soft spot just as you walk in...once you step off the steps into the kitchen.  Its a very large soft spot, easily 2x2.5 feet...and I have determined that it is indeed a design flaw.  If you look under the rig, its not supported by anything!  So we are going to weld in some cross braces to bear the weight rather than tear anything up.  You can actually watch the floor sag downward from under the rig when someone steps in that area.

Kev

[hose-man]

I did the repair/mod that kevin detailed above last year.   It was easy & effective.   2x2 square tube running from cross brace to cross brace under the soft spots.   Plenty of room to work above & around the drive line.   Just beware of any accumulated leaked oil or tranny fluid in the area you're welding.    It might be prone to ignite with the heat  of welding.   I had an exiting moment when I finished a weld & had to beat back some flames.

[LJ-TJ]

 Hm? Well I was going to suggest about the same thing. Get someone of weight to walk, stand, modestly bounce on the soft spot while you lie under the rig to see where it is giving. From that point you can establish if it is just a case of reinforcing it like the Kevin and the lads suggest.

[tiinytina]

Just wondering if anyone has tried durarock (cement board) over the ply, laying so seams are 90's to ply seams or solid sheet over seams etc, screwing and glueing it down to ply then laying flooring on top? This is what we do on home floors when putting down tile to stabilize the floor. Durarock will add weight and 1/2" height... This was Pat's thought on the topic.....

Tina

[ClydesdaleKevin]

Not a bad idea Tina...except the weight part...for us it would be impractacle since we are already carrying around about the max this Itasca is rated for.  That's why we didn't opt for tile or stone flooring, even though its the best for fulltiming it, especially with pets.  When we get that far we'll be putting in laminate flooring over the floor...that's as much weight as I want to add.  That's after we finish the cabinetry work and install the Splendide washer/dryer combo.

Kev

[hose-man]

Durarock, or Hardybacker are both good backing for tile over a fairly sturdy wood floor.   The problem is, the floor that already feels spongy is going to have too much give & will flex enough that the durarock & hardybacker will crack, break & degrade beneath the tile.   Result will be broken grout lines and popped tiles.  Not to mention that the floor will still be soft & spongy in that area.   

[RV Mech Tech]

hose-man is correct-  this happens on new RV's with a proper well prepared floor and subfloor in big high-end coaches -  have seen several of them with cracked tiles and grout - one so bad it had to go back to the factory and be re-done- but many of them do not have problems so must be in the preparation of the subfloor- also take into account that RV's twist and flex all the time so the subfloor must be solid enough so that there is no flexing at all- and as mentioned think of the weight added to the coach - In doing some bathroom renovations in the past in houses made in the 30's and 40's they have original tile usually in the bathroom only and they are still in good shape- take a look underneath in the basement ceiling and you see a three to four inch solid subfloor of concrete under the tile in a box structure .  Hm?

[tiinytina]

good thing to know! and here I thought it would be a new and innovative plan... ah well....
Tina

[stopngo]

This  may or may not be what you want to hear. I replaced the floor in the bathroom due to major weater damage and rot at base of toilet. all turned out well. Then i had asoft spot at the entrance area. So i figured i would find the same thing. After cutting out a large area of original floor (that BTW did not show any water damage) I removedall the 1 in thick styerfoam insulation which had been compressed to 3/4 in below that is the steel panel that covers the entire area that the whole body sits on I installed new styerfoam and new plywood & added a 2inx2in oak board on top of the frame under the steel pan  recovered the entire floor, A nd it still feels exactly the same as it did before. What i reccomend is to ignore the soft feeling and spend your time elsewhere -  Frank 

What i reccomend is to ignore the soft feeling and spend your time elsewhere

Best advice I ever heard. I like it. Saved me a lot of work