How bad is this 2004 TAB floor ?

MikeT

A friend is selling a 2004 TAB T16 (number 299 manufactured in November 2003) that is in excellent condition except for some questionable areas in the floor. Everything works: Cool Cat, power converter, Northern Breeze vent fan, Norcold 3 way fridge, etc. It has all options except propane heat and includes cover, external tent and external canopy. The trailer has mostly been covered and parked in a local campground so the exterior and bottom look almost new. Total towing distance since 2004 is probably less than 2000 miles.

My concern is the floor. Inside the door sill and spanning about 6 inches into the interior, the floor is soft - see picture. If I pushed hard with the tip of my left shoe, it might go through the floor top layers. Underneath, the floor waterproofing mesh membrane looks fine and is tighty adhered except under the entry door area and on the left side under the Cool Cat. In those 2 areas the mesh membrane has delaminated. Pushing up on that area there is a crunchy noise that may just be the mesh moving or may be delaminated plywood. At the door sill, the floor sags almost 1/2 inch where it meets the cabin wall. Looking underneath, the floor has sagged at the outside rear of each wheel well where the vertical cabin wall meets the floor. See the circled area in the 2 underneath pictures, the sag is at least 1/4 inch.

I am wondering if the original Dutchman floor design was adequate. Much of the cabin wall and roof weight is bearing on the edge of a floor structure that cantilevers out from the Alko chassis rails. That cantilever is bound to flex some, but does 1/4 inch sag at the outside rear of wheel wells indicate impending strucural problems ?

I could cover and reinforce the 2 soft areas with metal above and below, but that wont address the sag at rear wheel wells.

It would help to know if others who own Dutchman TABs observe any sag of the cantilevered floor similar to my pictures. Does the new floor used by NuCamp since 2017 have a stronger structure that does not exhibit any sag as it cantilevers out to meet the cabin walls ?

Thanks, Mike

Grumpy_G

Not many people around with the early T@bs. The soft spot and crunchy noise definitely is a problem. If the trailer is in an area with high humidity I could imagine condensation crept in under the door and through the cool cat opening. The body is not solely supported by the floor (at least for later built units), there are wooden beams running across at the front and rear plus all the interior cabinetry helps supporting the outer shell. 

Is the "drop" only in the areas you mentioned or is it noticeable up and down the length of the trailer ? That would give an idea how much of the floor compromised. 

VictoriaP

@Geo, can you advise? I know you have knowledge on these.

Sharon_is_SAM

DM floor info here:

https://tab-rv.vanillacommunity.com/discussion/comment/114121#Comment_114121
https://tab-rv.vanillacommunity.com/discussion/comment/44911#Comment_44911

https://tab-rv.vanillacommunity.com/discussion/14426/dutchmen-t-b-owners-with-original-floor
https://tab-rv.vanillacommunity.com/discussion/comment/89153#Comment_89153
https://tab-rv.vanillacommunity.com/discussion/comment/48459#Comment_48459

Geo

@MikeT,  From your brief description and pics it seems as though you are dealing with a rotten floor.
The most susceptible areas in DM T@B's are the wheel wells, front corners, cool cat opening, and door bottom.  The crunchy sound at door area is delaminated plywood, the sagging edges is the floor structure falling apart.
The luan plywood used by Dutchman is not water resistant nor did they use waterproof glue. 

IMHO  -  you need a whole new floor. . .  It's worth it to make your vintage T@B new again.

  

VictoriaP

@MikeT NuCamp does sell & ship a replacement composite floor, for several thousand dollars (not sure of exact cost this year). The composite floors do not rot the way the old Dutchman floors did. Then you have to either DIY the install (a major undertaking, as you can see from Geo’s pics, the entire shell must be removed) or have it done professionally, which of course, is more money. Last I heard, NuCamp can do the install at the factory if you are close enough to get the trailer to them.

MikeT

@Geo, On the 2004 TAB I am considering, the only water damage appears to be in the area of the Cool Cat on left side and door bottom on the right side. Everywhere else the underneath waterproofing mesh looks fine and is tightly adhered to the bottom plywood. Looking inside the rear bottom cabinets and under the front cabinets there is no evidence of water intrusion, although I have not pulled  up the vinyl flooring. The floor feels solid inside the cabinets. The plastic wheel wells are tight against the adjacent surfaces with no gaps. Caulking beads along the exterior aluminum and plastic trim (sides, bottom front, bottom back) are well adhered and look almost new, probably a consequence of the trailer being covered much of the time.

Does a Dutchman or NuCamp floor in good condition have any downward flex due to cabin wall loading at the cantilevered edges in front of and behind the wheel wells ? Or is any flex an indication that the aluminum tubing is abnormally bending, even though the plywood might be OK in those areas ?

Thanks, Mike

Nova

Hey Mike, Nova here. Geo helped me out with my floor replacement performed in 2021.  So, I bought the new floor from NuCamp and spent the big bucks.  It is far superior to the original that had a lot of wood and veneer that had black mold rot.  It seems very tight and solid now.  I do not feel sag and I am not a sight guy.  

Mouseketab

Per the factory tour, I took in June, getting a floor blank from nuCamp may be difficult or a long wait. They are currently out of the previous Dutchmen floor blanks they had created. They have switched the way the nuCamp floors are made and are working on R&D to make the Dutchmen floor blanks from the new materials.

MikeT

@Mouseketab Thank you for the information about nuCamp floors. Is the original vinyl floor in the DM TaBs glued down or just stapled around the perimeter ?

Mike

Mouseketab

MikeT said:

@Mouseketab Thank you for the information about nuCamp floors. Is the original vinyl floor in the DM TaBs glued down or just stapled around the perimeter ?

Mike

Stapled. I removed my original vinyl to monitor any wetness. I will eventually need a new floor, but mine is not rotting, it's just the internal frame that is warping.

Geo

@MikeT,  The downward flex at the edges of your floor is most likely due to the aluminum internal floor framing failing. The framing plus plywood together creates a unibody style structure to give it it's load capacity. The AL frame have spot welds that rely on the plywood glued to it (considered as one unit) for its structural integrity.

Several folks here have done creative patches and repairs to limited areas of their floor. I have not heard how many were successful as follow up posts on many projects is limited.  


You definitely do not want this to happen. . .

MikeT

@Geo That picture shows the importance of floor structure and wall-floor connecton integrity. To really understand the condition of the floor structure, I would probably have to remove the rear floor cabinets, the Cool Cat and the lower kitchen cabinets. Then the vinyl floor covering could be removed to reveal the condition of the plywood.

Thanks, Mike

rfuss928

MikeT
It's very important to understand that the floor strength is totally dependent on the bonds between the core (aluminum tubes) and the skins (plywood sheets).  Any one of the components on there own are incapable of any meaningful support of the trailer loads.  Much like corrugated cardboard is just three sheets of paper without the glue.  Even if the plywood looks solid (unlikely). if the 18 year old bonds between it and the aluminum tubes are failing (likely), the strength is lost.  One of he first sign of a sagging floor is in the wheel well areas of the interior.  You will find the tops of the side benches do not sit flat and square any longer and the center support is breaking loose from the outer wall or inner framing. (Some examples pictured below).  High mileage and rough roads aggravate the condition.
Everything is repairable but this problem is not a matter of patching or replacing bad areas.  The floor assembly has to be one single solid structure.  
Good luck...
Bob

Bench top center support - outer wall


Bench top center support - inner bench front

MikeT

@rfuss928 Thanks for the pictures. On the 2004 TaB I am considering, the bottom benches do not have the problems shown in your pictures. Probably that is because the trailer has traveled so few miles and the floor assembly has not been stressed much from road bumps and vibration. In the tabtrailers@groups.io internet group I found a picture of the original TaB aluminum floor frame (see below). That frame looks way undersized - the aluminum tubing walls are very thin and there is not much surface area for bonding to the plywood floor skin.

The floor assembly transfers the cabin wall/roof loads (probably several hundred pounds) to the top of the AlKo frame members. Those loads are cantilevered about 1 foot out from the AlKo frame and place great stress on the floor structure. No surprise that cantilevered sections of the floor sag after years of loading, even if the plywood is not damaged by moisture.

With steel tubing and braces, the cantilever sag could possibly be reduced. The best fix is a new floor that is properly designed to withstand the cantilever loads and moisture intrusion.

Mike

Original DM TaB aluminum frame. This person ended up fabricating a new floor with thicker wall tubing, additional braces and marine grade plywood

rfuss928

MikeT  You're on the money with your understanding of the floor structure and loads.  If everything is "perfect" the structure is a strong, lightweight platform for the trailer body and very limited contents.  If you follow the GVW rating on the trailer, there is only room for 2-300 pounds additional depending on options (like the CoolCat).  That means one can add very little to the trailer.  If it didn't come with the trailer it is added weight including kitchenware, water, tents, awnings, bedding...  It adds up fast.  Then to make matters worse, perfection is fleeting and the capacity decreases as flaws develop.
The photos from the old forum may be those from a friend who had a very detailed thread on his complete floor rebuild and replacement process.  He often said he should of bought a floor from NuCamp in retrospect.