Soft spot in floor

[Luke Croll]

Good afternoon. I have a soft spot in the floor of my 2011 Laredo 300RB. It is right above my grey tank and has been getting worse little by little. The spot is not much bigger than 2'x2' and everything else around it is very solid. When driving this spot in the floor is covered by my super slide. It is right next to my front living space heating floor vent. I initially thought it was just shoddy construction right around the vent but it seems to have gotten worse. My kitchen sink is w/in 3' of this leak but I assumed that it just dropped right into grey holding tank. Any help would be lovely. I am not shy about pulling up flooring or dropping the bottom either, I am just wondering if anyone has had a similar problem with their unit. Thanks again.

[ctbruce]

It may not be a leak at all. It could be the Styrofoam breaking down in a sandwich board floor. That would be the 1st place that I would look.

[JRTJH]

I agree with Chip. It's been about 5 or 6 years that the manufacturers have been using what Keystone calls "Helium technology" to reduce trailer weight by as much as 2,000 pounds... Part of that is the foam laminated floors in the light weight trailers. It sounded good back then, but now that they've been in use for a while, it sounds like we're hearing more and more reports of "spongy" or "soft spots" on the floors.

It could be water damage, but I wonder if some of the complaints might stem from the floor "delaminating" in areas of heavy use by "heavy footed users".... Areas like the "jumping off spot" for kids to get out of their bunks, the space right in front of the kitchen sink and stove, or areas where people stand and put a lot of weight on a small "footprint" of the floor.....

The construction is typically either a 1/4" OSB top layer glued to 1.5" of white construction foam and the bottom is a 1/8" luan panel. On some models, manufacturers opted to glue two of the 1/8" luan panels to form a 1/4" top panel.

So, if you can imagine "stomping" on a sheet of 1/4" OSB in the same spot for several years, that may be what you'll find rather than water damage... Be sure to let us know what you find because several members are facing the same situation and it may not be water leaks.....

[Luke Croll]

Thank you for the input. I thought that might be the case. This is a very trafficked area since it is right next to the counter. Everyone has to walk right over it to get through the kitchen to the rest of the trailer. I am 6'5 and about 245 so I walk with a thud haha. I am planning to tear into the floor from the top first. I will let you know what I find. Best case scenario being just a weak sandwich floor is there a known way to strengthen the design? Or will I be able to just rebuild what has failed? Thanks again.

[JRTJH]

If you repair from the top, you may be able to pull the weak/damaged flooring out, reinstall rigid foam board (pink stuff from Lowe's) and if you use slightly thinner foam, you could install 3/8" or even 1/2" OSB or plywood and come very close to the same overall thickness. The rub is that you need to maintain the same clearance for the slides, so any modification will need to address slide movement.

Keep us posted as your project develops.... Good Luck !!!

[Msmith2054]

Good afternoon. I have a soft spot in the floor of my 2011 Laredo 300RB. It is right above my grey tank and has been getting worse little by little. The spot is not much bigger than 2'x2' and everything else around it is very solid. When driving this spot in the floor is covered by my super slide. It is right next to my front living space heating floor vent. I initially thought it was just shoddy construction right around the vent but it seems to have gotten worse. My kitchen sink is w/in 3' of this leak but I assumed that it just dropped right into grey holding tank. Any help would be lovely. I am not shy about pulling up flooring or dropping the bottom either, I am just wondering if anyone has had a similar problem with their unit. Thanks again.
I have a 2013 Laredo 291tg with what appears to be the same problem. My soft spot is right next to the floor heat register, but I am detecting a few other spots that also seem to be giving way. I usually walk around barefoot in the tt and am 270 lbs, heavy on the heel. Just recently I can hear a distinctive cracking sound like splintering wood right by the register.
I am planning on pulling the flooring up and seeing what the problem is this winter. Any thing you find will probably be similar to what I will find, so please share. I will do likewise. Anybody else can chime in also, especially about what I should find after I remove the vinyl floor? How is the subfloor installed over the frame? What method is used to attach it?

[wiredgeorge]

Why not remove the heater vent to see if there is any indication of damage; perhaps wetness or signs of wetness. If a repair is needed, it would be easier if you knew a little more to zoom in on better answers. Sounds like you have the same construction as noted previously in this thread based on age. I would also take a close look for signs of water penetration up top; Look in nearby cabinets that might have a line with water in them to start the investigation. Water can also get in via window seals and the like so check these things before ripping into the floor.

[megamile]

I have same issue at kitchen floor heat vent on NY 2017 Hideout 315 RDTS. Very small spot about 6" right at one side of register. No water or dampness there at all; no lines or leaks, and no spillages either, doesn't seem to be getting larger but I weigh 330 lbs and am concerned... Any ideas on how to strengthen it without having to rear up the floor?

[Msmith2054]

Why not remove the heater vent to see if there is any indication of damage; perhaps wetness or signs of wetness. If a repair is needed, it would be easier if you knew a little more to zoom in on better answers. Sounds like you have the same construction as noted previously in this thread based on age. I would also take a close look for signs of water penetration up top; Look in nearby cabinets that might have a line with water in them to start the investigation. Water can also get in via window seals and the like so check these things before ripping into the floor.
Thanks George, but there are no water issues. Even did a pressurized soap bubble test. Just trying to get as much info as I can on construction so I know what I “should” see when I pull the vinyl flooring up, such as, sandwiched foam board laid across the top of framing, or what?

[JRTJH]

You "should see", starting at the top, a thin, vinyl floor covering, a 1/4" OSB (or two 1/8" luan ply sheets), 1.5" white rigid foam sandwiched between the aluminum floor stringers which are 2x2 or 2x3 square tubing, and an underlayer of 1/8" luan. The entire assembly is "wrapped" in DARCO, which is a "black plasticized, nylon reinforced, waterproof fabric" (think blue poly-tarp). All of this is laid on top of the steel frame rails and fastened to the outriggers along the extreme side edges of the floor. The inside walls are then placed in location, the shower and large floor standing cabinets are installed, then the outside walls are placed in position and secured to the outriggers with bolts through the floor.

Taking the trailer floor apart will be "impossible" if you try to do it in one piece because the walls are fastened above the floor. You'll need to carefully identify the location of the floor stringers, then remove the flooring in layers, being careful not to damage the underlying structures. You'll need to work around the "rigid heat ducting", the floor stringers and any electric runs that might be embedded inside the floor. Typically the electric/plumbing runs are under the floor or above the floor (inside cabinets) but as sure as you "decide they're not embedded in the foam is the one time you cut through something important and not repairable.... So, be careful.

There are a few threads in the past couple of months with photos of repairs people have done to their sandwiched flooring. Looking at those photos will give you some ideas on what you "might" find.... MIGHT is not always what you'll see in your specific trailer......

[JRF16]

You "should see", starting at the top, a thin, vinyl floor covering, a 1/4" OSB (or two 1/8" luan ply sheets), 1.5" white rigid foam sandwiched between the aluminum floor stringers which are 2x2 or 2x3 square tubing, and an underlayer of 1/8" luan. The entire assembly is "wrapped" in DARCO, which is a "black plasticized, nylon reinforced, waterproof fabric" (think blue poly-tarp). All of this is laid on top of the steel frame rails and fastened to the outriggers along the extreme side edges of the floor. The inside walls are then placed in location, the shower and large floor standing cabinets are installed, then the outside walls are placed in position and secured to the outriggers with bolts through the floor.

Taking the trailer floor apart will be "impossible" if you try to do it in one piece because the walls are fastened above the floor. You'll need to carefully identify the location of the floor stringers, then remove the flooring in layers, being careful not to damage the underlying structures. You'll need to work around the "rigid heat ducting", the floor stringers and any electric runs that might be embedded inside the floor. Typically the electric/plumbing runs are under the floor or above the floor (inside cabinets) but as sure as you "decide they're not embedded in the foam is the one time you cut through something important and not repairable.... So, be careful.

There are a few threads in the past couple of months with photos of repairs people have done to their sandwiched flooring. Looking at those photos will give you some ideas on what you "might" find.... MIGHT is not always what you'll see in your specific trailer......Had same problem with our 2016 Outback Terrain. Started developing soft spots around all three floor vents. Started to feel like the floor was going to give way. I opened the bottom and placed additional cross supports between frames close to the vents on both sides. Used 1x2 rectangular tube so that there was clearance for the heat ducts. There is still a little flex in the floor.

The sandwich floor is very poor construction and doesn't have any good solutions for repair. The bottom thin plywood was loose on the entire bottom. This should be the strongest layer but is the weakest. Very poor bonding of weak materials. Then there are the stresses of just the fastening the floor to the frame, flexing from walking on it and traveling. This is why I chose to support from underneath. Also when the screws holding the vents stripped I put glue in the holes which I found out later had dissolved the styrofoam.

I suspect there is moisture due to condensation from the tanks that affects the cheap bottom plywood.

[German Shepherd Guy]

This is a big job. Had a 2007 Zepplin. Water damage in the bedroom. Had to replace floor. Top layer 3/16 plywood/ then 1.5" foam/ then 1/8" bottom, which was plywood too! There was no sub structure, only the plastic wrap that enclosed the bottom of the trailer and then the ground! I had to build a 2x2" frame and then put 1/8" tempered board on the bottom. Then bolt the frame to the few and far between aluminum cross members. Then "joist" the frame with more 2X2 and then put 1.5" foam insulation in and then cover the whole with 3/16 tempered fiber board top. Worked like a champ but I was truly astonished when I first removed the linoleum. Had no idea. I think preventing moisture condensation is crucial in a TT. :facepalm:


Oak

[Bill Kidd]

We just bought a 2010 Outback 210RS and I have the same problem. I removed the vents and the boots and found that when they were cutting the floor to allow for the vents they used a skill saw. So instead of a nice clean cut rectangle, they cut past the corners and that is where the floor begins to de-laminate. It is clearly a manufacturing issue. If they had used the appropriate tool for the job, there may not have been any issues. I plan on removing the liner on the bottom and adding aluminum supports. I was very disappointed to find this from what seems to be a well built camper.