Loose frame bolts and deterioration of floor.

[Ak Ron]

I started doing some spring cleaning on my 2004 Outback and noticed that the two front bolts were loose. I couldn't tighten them as the heads would turn. Cutting through the floor fiberglass showed that the waferwood around the carriage bolt head there was soft and very wet. (PS: This photo is from the door side front storage area)

It seems the only way water could have gotten in is from below, possibly from the loose bolt??

Any ideas on what to do now? I want to dry the wood somehow and replace the bolt, probably using a large washer or plate inside. I will probably want to re-seal the interior fiberglass too like it was.
Ron.

[RRJR]

I would dry out the wood as much as possible then fill the hole with a good waterproof putty and then put a large washer on new bolt and snug it up securley.

[Thomas G.]

Originally Posted by RRJR

I would dry out the wood as much as possible then fill the hole with a good waterproof putty and then put a large washer on new bolt and snug it up securley.

I would dry out the wood, then fill an oversized hole with fiberglass resin, then drill the correct sized hole in the middle for the bolt.

[RRJR]

When redrilling it's best to drill upward thru the chassie to get a correctly centered hole.

[Glenn Baglo]

Check out Git-Rot. I used this product on my old boat.

BoatLIFE | How to use "Git"-Rot

[Carol H]

I would give Trillium/Outback a call to see what they would do to fix it if it were at their factory .

[Francesca Knowles]

That looks like particle board to me...that stuff is like a wick once water gets started. Can you tell how far the "wet" has spread, and does the rest of the subfloor seem sound?

Francesca

[Ak Ron]

Thanks for all your ideas!
I worked some more today on it and (timidly) expanded the hole to about 4x4". still finding wet stuff and soft as well. I have a question in to Outback for their thoughts also. Will let you know what advice I get from them. I fear this could get bigger.
The lesson from this for me is to keep those bolts tight so water doesn't have a chance to get in...maybe even seal the bolt hole with something at the time of manufacture..

[Donna D.]

Humm, you think it came from underneath... has the trailer been parked? I can't figure out how water jumps from ground to a bolt unless the trailer is parked in a puddle to the bolt. Is it possible it's wicked during driving in the rain or do you think something is leaking from above?

[Ak Ron]

Not sure how these are constructed, but I am imagining a sealed bottom with a wafer wood sandwich between fibreglass...no way for water to get in except through a hole in the outer skin. Driving in wet weather might allow it if the bolt was loose..it seems like there is a rubber gasket between the shell and the frame which, if tight, might prevent water getting in.

[Francesca Knowles]

I disagree that the water is likely to have intruded from the bottom in this case. The body sits flat on the frame, and the bolts go through two layers of fiberglass, the subfloor, and two inches of the frame itself. That's a long way for enough water to climb to saturate the subfloor.

I think it's more likely that the water has gotten in from above- the trick is going to be to find out just where.

Francesca

[David Tilston]

Did you say the hole is now 4" across? I assume that is just on the inside. What type of wood is it? Hopefully not particle board.

[steve dunham]

Why don't trailer manufacturers use treated plywood (foundation grade) like they use in homes for basements ? I know it would cost more but would go along way in stopping rotted floors and since it is sandwiched in fiberglass or sealed in fiberglass resin and covered it would not be exposed to human contact.

[Thinh]

...Just do the work like....mine. I found out the previous owner had leaks from front window's frame. So, I cut out all the rotten woods, replace with the same thickness, new, fix the leaks and .....TESTING IT WITH GARDEN HOSE AT MAXIMUM RATE OF WATER FLOW. Good luck, Buddy. Here are some photos of mine:...You could see in the photo one of my front bolts, brand new, heavy trucks' bolts with new and thick washer. F.G resin cover on top after tightening.

[Thinh]

...One more thing from my works..Once for all...Any new piece of wood/stud to be put in, I gave it a coat of...water proof chemical and after installed, cover them with resin if possible...Just share my works...

[Ak Ron]

Another update: I talked to Outback today and they said basically they would cut out a piece, dry it for a while, replace piece and then fiberglass over after bolting. Outback says they currently use plywood for this floor material.
Attached is a current photo of the project.. The hole is about 4"X4". The wood is definitely wafer wood or OSB. At this point I think I will put a fan on it for a week to dry as much as possible, cut a piece of pressure treated plywood, replace bolt with stainless steel one, cover it all back with resin/fg. I am still exploring any possible entry point for the water, but the way this is built I don't see how water from the inside could get through the FG floor. The damage also seems concentrated around the bolt hole.

Steve: PT wood makes a lot of sense, along with using all stainless fasteners, and galvanizing trailers like boat manufacturers do. I'll bet this fgrv group could design the ultimate RV that would last centuries!

thinh: wow...what a project.

[Francesca Knowles]

I wonder about the structural integrity of sticking a piece of plywood in there, more or less just next to the surrounding material. Shouldn't it be "joined" somehow? It'd be one thing if this was a patch of floor elsewhere, but this is a major fastening point that helps hold the shell to the frame. Even if covered with fiberglass cloth, I think it will be seriously weakened.

It might be appropriate to consider performing the repair as planned, but relocating the fastener to a different, structurally sound place farther along the frame but in the same general area.

Francesca

[Thinh]

You got that right, IMO, Francesca. Not only I reinforced the frame with extra cross members at beginning of project, but I also glued at the joint of any new plywood which will be put in for replacement. I screw it down at the edge with a few metal plates along the cut to make sure no weight affected to the F.G shell below....

[Andrew Gibbens]

Here's my suggestion of a boatbuilding repair to that problem. Let in a decent size piece of plywood, so that there is room to work around the frame rail and so the joint between the patch and the original floor isn't too highly-stressed. Laminate fibreglass top and bottom to connect the patch to the floor. It's not perfect to leave out the area over the frame rail, but it'll do.

To laminate fibreglass overhead like this, lay it up downhand on a piece of plastic, then press the fibreglass/plastic combo into place on resin-wetted plywood and carefully peel off the plastic, using a resin brush to keep it in place.

This would be about as strong as the original floor, though that be more repair than it really needs.

[Raz]

My previous camper used bolts and self drilling screws to secure the trailer to the frame. While the bolts were fine the self drilling screws rusted out in about 3 years. I suspect either the screws stretched or the floor compressed (or both) and allowed water between the floor and the frame. I discovered the issue when I noticed the tops were rusty and the screws could be turned by hand. In some cases the screws were 1/2 there original diameter. Curiously, Scamp uses the same type of fastener to hold the floor down on there trailer yet no one has reported any problems.

In regard to the current issue, I would consider adding a metal plate to Andrew's solution. Good luck, Raz