Trailer floor and wall wood rot

Hello all! New to this forum. Found it through my search for resources on how to repair wood rot. Me and my partner just bought a 1984 Road Ranger 24? model 244 travel trailer. New to the game, I did my research on signs we should look for when buying a used RV, so I thought we were set but upon bringing home we discovered the holy grail of trailer damage (the guy who sold it was either negligent/completely oblivious or knew it because he said there wasn?t any water damage) ... super extensive wood rot. So far we?ve uncovered about 75% of the floor and in a part by the door (where it is the worst so I knkw we will have to address that leak) we can see the ground through the floor. A few (major) questions:

1) How should I remove the rotted floor? I have seen people post that they do it with circular or reciprocating saws l, but I?m worried about electric or gas or pipe lines in the floor, since I have no idea the layout of that stuff.

2) I?ve seen some people post about a metal flooring sheet under the subfloor. Do all rvs and trailers come with this? Or is it too old to hope that that is there?

3) Does anyone have any resources for used rv windows, screen doors and new doors? The ones on it are ok (a few with holes in the screen). I knlw that there is water damage in the walls that came in through the windows because there are soft spots around them.

Thanks for any help or advice!

Hi SiSi, Welcome to The RV Forum!

The best way to cut through the floor is with a circular saw set just deep enough to cut through the flooring without seriously nicking the supporting beams.  The advantage of a circular saw is you can precisely set the depth of cut, a reciprocating saw's blade goes up and down so it's more likely to hit stuff under the floor.

Look underneath the trailer - you should see the gas line running there.  It will likely be an iron pipe with copper tubes going up through the part of the floor that's under the cabinets to the stove, refrigerator, water heater and furnace.

The electrical wires usually run through the walls, not the floor.  Any wires run under the floor or through the walls will pass through the middle of the 2x3s or 2x4s so they'll be an inch or so below the floor surface  This way they're less likely to be hit by a stray nail and this is another reason to use a circular saw set just deep enough to cut the flooring.

If there's a metal undersheet, it will be underneath the supporting beams so you won't cut it while removing the flooring.

If you disconnect the trailer battery and unplug the trailer, all of the electrical wires will be dead just in case you come across one.  Use an extension cord to power the saw.

The best way to approach floor replacement is to grit your teeth and cut an inspection hole between the floor beams using the rotary saw.  Then you'll see what's underneath.  It will probably be fiberglass insulation, maybe a rectangular metal duct for the furnace if you have floor registers, and 2x4 beams.  Once you see what's there you can expand the hole until it's the size you need.

When you patch the floor, cut away until you come to one of the floor joists.  A 2x4 is 1 1/2" thick on it's edge, so cut the flooring down the middle of the beam so it can support both the remaining floor edge and the new piece.

Unless the windows are damaged, there's no reason to replace them.  RV windows are held in by sandwiching the wall between their inner and outer flanges.  Most leaks come from deterioration of the putty used to seal their outer flange.

Unscrew the inner flange and you can push the window and frame out from the RV's wall.  Fix whatever water damage is there, then apply new putty and bolt the window back in place.

Excellent and very comprehensive answer from Lou.

Thanks Lou! We just started our gutting yesterday and it will be a few weeks before we can get working afain possibly, but I will keep you updated and I?m sure I?ll have more questions?.

When replacing supporting beams in floors or walls, what kinds of screws should I be using? Should I place a vapor barrier between my new subfloor and whatever flooring we choose? (Still haven?t decided on what flooring, we ripped out some wood paneling flooring that was secured using screws just straight through the top, guy either didn?t know what he was doing or didnt care about the look).

Any reccommendations on rv flooring? Going for a relatively modern look, no tile due to weight. Something preferably acratch and water proof as we have several furbabies who will be living with us/around on my parent?s property.

Stainless steel deck screws would be my choice.  Water damage is incidious.  Unless you locate the source and stop it you will continue getting wet.  Once you have the floors opened up and fixed any rotten framing I would jot hesitate to use a vapor barrier of some sort.  Your end game is to stop any moisture.  I would lay the moisture barrier first, then floor joists, insulation followed by half inch plywood.  Marine ply would be best, butmprobsbly too expensive for your budget.  Home Depot sells a line of snap lock waterproof vinyl plank flooring that is not too thick and has a long life.  I would not hesitate to use something like that.

Donn,

I think the water damage was from leaking seals arund the door on that side of the trailer and on the other side seals around windows wore down due to age and it never was re-finished. The guy had told me he was second owner, first was an older couple who didn?t bother with maintenace. But the way this guy treated the trailer I could see that both owners didn?t care too much about it.

For the vapor barrier, you?re saying I should lay it below the joists? Wouldn?t I want to do it after i put the subfloor in and right before our flooring of choice? So that I don?t run into a rotting subfloor if another leak occurs?

I knew when I started pulling the floors up that I was going to be in for a long haul, which is exactly what I wanted, but just didn?t have allcthe knowledge necessary?

Thanks for the tip on the flooring choice and screws! Will definitely look into it.

I would put a water proof barrier down first.  If you were to put it on top of the joists the insulation would be exposed to the elements and not last very long.
When you get to the windows and doors be sure to use butyl putty tape between the window and wall.  That is your primary sealing.

donn said:

I would put a water proof barrier down first.  If you were to put it on top of the joists the insulation would be exposed to the elements and not last very long.

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In other words, the vapor barrier is the lowest most element.  The easiest way to install one is to work from underneath the trailer.  There may already be one in place in the form of a metal or plastic fabric underbelly, if it's intact that's all you need.  Otherwise remove the metal or plastic from underneath the trailer and replace it.

Here's one of many links on youtube demonstrating the repair of a trailer floor. This is a 9 part video. It' may give you some ideas on techniques, etc.

https://www.youtube.com/watch?v=W885oTyO3dU

So I checked under the trailer for that weather proofing and all spots that I can see water damage from top are good except right under the stairs. Totally destroyed from the constant weight put on the rotting floor which put weight on the rottig joists which pushed down and put holes in the metal underside sheet. Forum wouldn?t let me upload any pics I took because he file size it too large.
Once I get the flooring and rotten joists out how do i go about repairing this?
Do I still repair from the bottom/how would I secure or do I put it down in there from the top and seal the underside edges?
What material should I be using? Metal flashing from HD?

Be aware that if you have an aluminum framed trailer the slightest nick can cause a stress crack, so be careful with the saw depth.

I removed my floor one sheet at a time after gutting the inside.  It goes pretty quick, and there were wires run along one of the support beams, so be careful.

One thing is unless the damage is extremely localized, do yourself a favor and just replace the entire floor.  You may find other issues, and now is the time to find them.  Also avoid working around other items that you don't want to be bothered to remove.
These things are like puzzles, and everything is interconnected.  I wasted time (for instance) avoiding dropping the holding tanks, and had to work around them a lot only to have to remove them anyway.

Gods Country said:

Be aware that if you have an aluminum framed trailer the slightest nick can cause a stress crack, so be careful with the saw depth.

I removed my floor one sheet at a time after gutting the inside.  It goes pretty quick, and there were wires run along one of the support beams, so be careful.

One thing is unless the damage is extremely localized, do yourself a favor and just replace the entire floor.  You may find other issues, and now is the time to find them.  Also avoid working around other items that you don't want to be bothered to remove.
These things are like puzzles, and everything is interconnected.  I wasted time (for instance) avoiding dropping the holding tanks, and had to work around them a lot only to have to remove them anyway.

Click to expand...

So I?m pretty sure that the weather proofing/vapor barrier is only aluminum. The frame of the trailer doesn?t look aluminum, plus it?s from ?84, so I think it?s steel. I do only plan setting my saw to about 1/2 inch to avoid cutting any good joists and then using a hammer/crowbar/wide chisel to break the reat of it.

I took out the old toliet/plan on installing a composting toliet so do I really need to neep my black tank? Or can I drop and dump it? Watwr from shower and sink goes in greywater tanks tight?

Yes you did mention '84 duh. : 
I was referring to the frame of the box, not the trailer itself.  So yes I'm sure its wood.
Don't know anything about composting toilets, but if the tank isn't required I don't see any reason to keep it.

If you remove the black tank, check the routing of the bathroom sink drain.  Some trailers of that vintage routed the  bathroom sink drain to the black tank instead of the grey, to add some liquid to the black tank.

Not an insurmountable problem but something to be aware of.

Ah gotcha. Thanks for that heads up.

Due to the age, the frame and neck of trailer does have some rust spots on it, with the frame under being pretty much covered in rust but no visible weak spots. I have seen people cover the neck in rustoleum to help deter any further rusting, but should I consider doing that for the frame under the trailer? I wouldn?t want to put all this work in and in a few years it start getting weak due to rust. I do live in central CA near San Jose and don?t plan on moving it very often/taking on trips (truck I have now can tow but not the most comfortable to tow in) but I may upgrade to a bigger truck, just have no clue yet.

I would definitely fix all rust I can reach.  Use a wire brush on a power drill to remove the flakes and as much rust as reasonably possible.  Paint with Rust-O-Leum or similar Bare Metal Primer, then top coat the color of your choice.  Rust will continue to eat the frame unless it is removed and painted.

Grashley,

Do I need to wash/powerwash the frame after I sand all the rust away or can i just wipe/dust/blow it away? Only reason I ask is because I?d like to know if I needed to do this before or after I fix the water damage floors/torn holes in the metal weatherproof underbelly. I can?t wash the underside before because theres a hole in the metal sheet right up under where the stairs are.

Rust removal usually requires physical abrasion, i.e wire brush, sand blasting, manual scraping.  WHEN it is done does not really matter.  Do it when the frame is most easily reached.

Rather than use a Rustoleum type product once any flaky rust has been wire brushed I would use a rust converter type product - there are several brands. The true converters are usually a milky white chemical that you paint on slightly rusted area and it chemically bonds to and converts the iron oxide and turns it into a very hard, black paint like coating. Then I would primer, then paint.

This video is a great demo of just how well the converter works. If you choose to use a product like this note that you first pour a small amount in a clean, separate cup, then dip the brush in that. Anything in that cup must never be poured back to the main container because the rust from the brush will react with and ruin the whole batch.