Wet subfloor in a 2007 Safari FB 25'

[zayd]

Good evening, everyone.

I recently acquired our first Airstream -- a 2007 Safari SE LS 25' with the front queen, purchased from the original owner.

I'm using the winter to take care of anything I need to tackle before our season begins in the spring. First up: I noticed the vinyl in the rear street-side corner had curled up, so I investigated. One discovery led to another, and I cleared out the front dinette and bench to see the full extent of the situation:



This is the same shot with an overlay of the moisture content readings:



The higher concentration of moisture is around a particular deck screw which is more rusted than the rest. That spot (about 1.5" radius) is wetter than the rest of the damage and the plywood is swollen more noticeably there. About a foot towards the rear of the trailer from that spot, there is a fair bit of mold growth.

I took a look underneath and didn't see any obvious intrusion points, although that spot definitely seems to be where the water is coming in. But given the sheer area of wet plywood, it seems there has to be intrusion elsewhere as well. Or can water from that point travel to cover that entire area? As for integrity of the plywood, I'm not yet sure if it is soft enough to warrant replacement or if it can be dried out.

My other hypothesis was the rear bumper vulnerability that I've read about here. But if that were the problem, I'd expect to see moisture across the entire width of the rear.

Another observation: the rear street-side curved window (the dry corner) was replaced by the original owner after a break-in. The replacement was a factory welded-frame window. Could the moisture be coming into the other two mitered-frame windows where the sealant has likely failed?

I also cleared out the front bedroom and found some moisture there as well:



The damp spot in the center-right is at about 12-14% moisture content, while the rest is dry (5-8%). I've read about a spare tire mount problem that could introduce moisture. If that was the case, is this the spot in the floor where the problem would show up?

I'd appreciate your experienced opinions before I take it any further. I'm handy and will likely do any work myself to ensure it's done correctly. Thank you!

Zayd

[GMFL]

Water typically does not enter from underneath the trailer.
Check those panoramic windows for problems between the aluminum frame and glass.

http://www.airforums.com/forums/blog...nt-right-2995/

[A W Warn]

The plywood actually looks pretty good!

The first thing I would check: If your trailer has the rear bumper storage - The metal lid of the bumper storage intersects and penetrates completely through the exterior wall beneath the plywood into the interior. When water lands on that lid it can weep inward and saturate the wood floor. (search this forum for "wood rot rear bumper storage")

Typical leaks could be:
The perimeter of door, caulking or seals.
The perimeter of windows, caulking or seals.
The intersection of the end cap and roof/wall, especially the area near the end of the awning rail and awning brackets.
Roof penetrations - caulking at fan curbs, pan beneath AC unit, and caulk at plumbing vents.
Access hatches - seals or
Any light on the exterior - caulk screw and wire penetrations

Good luck!

[dmbecke]

I would pull the belly pan down on the back couple of feet from bumper forward and look from underneath
You will be able to see the extent of the problem
We looked at a 2003 with h same bumper issue

[Seemore2006]

We were told that some of the Airstreams had issues where the seam under the exterior trim (the horizontal band) wasn’t sealed. I’m not one ounce technical so this is my best shot at explaining -

Check where the upper body meets the belly pan (?) behind the trim over the rear bumper. The seam behind the trim was not sealed.

[skido23]

Check the marker lights on the roof. You can tell if they are leaking by getting on a ladder after a storm an looking thru the lenses. If you see a puddle of water inside the lens then you can be pretty sure that the water is entering the trailer thru the marker lights.

[Lucille915]

We have a 2006 Safari we bought second hand too. We have been chasing leaks for 4 years. Windows were a spot and also exterior lights. We have replaced the floor and epoxy patched the subfloor by the door. We are heading to JC this summer to get a pressure check and have the door realigned. Good luck to you!

[bradt]

I have a 2007 Safari 27 that I bought used and had similar moisture issues. Rather than the long story of all the repairs, here are things I learned as I discovered and fixed leaks. I found I really like Trempro 635 sealant.
Airstream has lots of areas where water can seep, or weep, between layers of materials. It can travel sideways a long way. Moisture at one spot can originate from a leak some distance away.
My 2007 had bubble foil on the underside of the plywood. It and the vinyl flooring above create a moisture trap. Moisture gets in by seeping sideways, and then accumulates, unable to drip out or evaporate. It can't ever dry.
All my marker lights leaked thru the mounting screws. They are not water tight as designed and leak thru the lenses. Moisture gets in the walls and goes down to the floor.
Roof penetrations caused some of my leaks. Inspect the caulk everywhere, and look for places where it has separated, formed a small crack, and no longer seals. Moisture can seep thru small cracks.
Fantastic fans can cause the roof to sag a bit and cause a puddle to form on one side of the fan, and the sag causes cracks in the sealant.
The belly band has many screws penetrating lots of areas. It has screws that go from the outside all the way to the plywood. Moisture can seep thru those screws.
Good luck and I hope you enjoy your Safari as much as I have mine.
Brad

[zayd]

All useful recommendations -- thank you. Right now, I'm waiting for some wet weather to pass so I can go out and continue the work. It will be in the 20s/30s, but I'd rather do this now than in camping season!

I'll check out everything suggested here and report back with findings when I have them. Thanks again for the guidance.

Zayd

[zayd]

An update while searching for the source of water intrusion.

I was hopeful that since my rear street-side plywood looked dry from the inside (see pics above), the bumper was not the source of the problem and I'd find a simpler fix. But dropping the belly pan and cutting away the reflectix proved otherwise. The plywood was wet the entire width of the back edge, right up against the rear bumper. That confirms that the bumper plate leak is my source (or at least the main one). Moisture readings were near 50% in some areas and the far corner in the picture below was crumbling.

Now it's time to research what it takes to replace the whole rear piece of subfloor.

[bradt]

Sorry you found so much moisture, but not a surprise. You can fix it to be nearly good as new.

My opinion is the reflectix insulation was well intended, but was a mistake because it created a moisture trap. I removed as much of it as i could get to.While you have the belly pan down, use a razor knife and remove as much as you can reach. Reflectix only provided a slight amount of insulation. I have not noticed any insulation difference with the reflectix gone.

Next spray every inch of bare plywood you can see with a 10% solution of Timbor, available from doityourselfpestcontrol.com or other sources. It will stop and prevent further rot. Spray from the top side too. Several applications.

Check under the bed and make sure the protective plastic has been removed over the carpet. If not, use the razor knife. I found the carpet damp. The idea is to make it possible for every thing to dry.

The carpet is stapled to the floor around the perimeter where it meets the wall. Remove all the staples so you can lift up the carpet and inspect for moisture. The carpet will stay put because the bed is on it. You dont gave to staple it back down. Spray the bare plywood under the carpet w Timbor.

You will find a black paint coating the plywood around the perimeter. My opinion is this was also a mistake. It sealed the surface and traped moisture inside. I used the razor knife can cut lines thru the black paint so it could breathe and also sprayed Timbor so it could soak in.

Evaluate if you can spot patch with epoxy products to repair your floor. It is a more involved process replace the floor. Not really hard to do, but more steps.

Use a straight edge and cut the vinyl flooring. You can decide to put new flooring just over the repaired area and have a seam, or, otherwise all the flooring in the whole trailer has to be replaced. That is a big job since so much furniture and cabinetry, plumbing and electrical are affected. I chose to allow a seam and now it does not bother me. But that is another decision to make.

My floor damage was beyond repair and I replaced about 4 feet of it. There are lots of little screws into the edge of the plywood from the belly band, which needs to be removed, all which are not sealed and water wicks in around the screw threads. Most screws will be rusty. You will want a new chrome vinyl bumper strip in the belly band when you are done.

There are large bolts that firmly fasten the aluminum shell to the plywood and to the steel frame below. They are hidden inside the double wall of the aluminum shell. These have to come out to remove and replace the plywood. They are hard to remove and I cut them out with a grinder.

Access to these bolts requires removing the interior aluminum planels, a straight forward but tremendous amount of work. I located the bolts from underneath and used a sharp new 2" hole saw to cut access holes in the interior aluminum wall at each bolt location. The holes are covered afterwards with tidy snap in hole plugs. Most are covered by furniture and I decided that although not historically accurate, they were not visible and did not detract from the Airstream aprearance. Not for everyone, but something to decide.

Meanwhile, during disassembly, notice how moisture has travelled sideways thru the plywood, and between layers such as under the vinyl floor, or under the bumper hinge plate. That is the thing you must eliminate by sealing the entrance points.

Good luck and enjoy the adventure. The Air Forums are invaluable along the way.

Brad

[A W Warn]

Originally Posted by zayd

An update while searching for the source of water intrusion.

I was hopeful that since my rear street-side plywood looked dry from the inside (see pics above), the bumper was not the source of the problem and I'd find a simpler fix. But dropping the belly pan and cutting away the reflectix proved otherwise. The plywood was wet the entire width of the back edge, right up against the rear bumper. That confirms that the bumper plate leak is my source (or at least the main one). Moisture readings were near 50% in some areas and the far corner in the picture below was crumbling.

Now it's time to research what it takes to replace the whole rear piece of subfloor.

Since the plywood is such good shape, there is no reason to replace the plywood. All you need to do is stop the leak, dry out the plywood, if there is some separation in the plies of the plywood repair appropriately, then install new floor covering.

This is what I did>

first
http://www.airforums.com/forums/f456...de-109059.html

second
http://www.airforums.com/forums/f36/...xy-108608.html

[skyguyscott]

Hopefully, you can dry out and salvage the existing plywood subfloor.

Replacing the subfloor is a real pain, but many have done so, there is some good advice here; you can search the forum on ways to do it.

There is a small group of us here who passionately believe in using Coosa Board as a replacement subfloor; it is a composite material used in the marine industry that is just as strong and easy to work with as plywood, but only 2/3rds the weight and is virtually water-proof, mold-proof and critter and varmint-proof as well. Yes it is more expensive than plywood, which is undoubtedly why AS doesn't use it instead. But it is totally worth it, IMHO to avoid ever having to replace the floor ever again!

[Isuzusweet]

Originally Posted by skyguyscott

Hopefully, you can dry out and salvage the existing plywood subfloor.

Replacing the subfloor is a real pain, but many have done so, there is some good advice here; you can search the forum on ways to do it.

There is a small group of us here who passionately believe in using Coosa Board as a replacement subfloor; it is a composite material used in the marine industry that is just as strong and easy to work with as plywood, but only 2/3rds the weight and is virtually water-proof, mold-proof and critter and varmint-proof as well. Yes it is more expensive than plywood, which is undoubtedly why AS doesn't use it instead. But it is totally worth it, IMHO to avoid ever having to replace the floor ever again!

A big plus one for Coosa board; (heck I'd demand Airstream build a new trailer with it right from the get go). I'm Coosa biggest airforums fanboy.

Water absorbtion is less than 1%; basically moistened the outside.

Here is my experience with subfloor rot and Coosa board.

http://www.airforums.com/forums/f311...me-106269.html

Cheers
Sidekick Tony

[zayd]

AW, I'm very tempted to leave the plywood in place. I could probably epoxy-impregnate that corner well enough, although there will be a good chunk of it that is inaccessible and under the shell. But the corner is crumbling and I'd feel better about pulling the rotten subfloor out and assessing and addressing all the water entry points. Haven't decided yet, so thanks for the perspective (and great write-up) on that option.

Brad, roughly how many access holes did you have to drill? As you said, most of them will be covered by furniture. And even for the ones visible under the dinette, I wouldn't mind a way to peek into that void in the future to check for moisture running down from the windows or above.

Scott -- If I employ Brad's hole idea and leave the inner skins installed, does that take the tedious work out of floor replacement? If I can get to the shell screws that way, the remaining fasteners are easy to remove and -- theoretically -- I should be able to slide the old subfloor out the side/back of the trailer and slide the new one in the same way.

Zayd

[skyguyscott]

Originally Posted by zayd

Scott -- If I employ Brad's hole idea and leave the inner skins installed, does that take the tedious work out of floor replacement? If I can get to the shell screws that way, the remaining fasteners are easy to remove and -- theoretically -- I should be able to slide the old subfloor out the side/back of the trailer and slide the new one in the same way.

Zayd

Sadly, no. By far, the most tedious part is fitting in the new floor under the shell. (unless you do a shell off, then it's easy, except for the part where you lift off the whole shell) I don't know any way to do this that does not first require you to pull out everything sitting on the floor you are replacing.

You could drill access holes to the bolts, then try to unscrew them or grind them off through the access holes you have drilled, but I guess I just don't understand how that approach would save you any time or effort over simply drilling out the pop rivets in each interior panel and having full and easier access to the bolts. Pulling off the interior panels isn't difficult and while you will want to be careful in handling the panels to avoid cutting yourself or denting or damaging the panels, is pretty straight forward and you then gain full access to all the bolts and can also assess the insulation, and critter trails, the rear tail lights, wiring etc. And you also then won't have to worry about denting or scraping the interior panels when you fit the new floor in.

I do find that sometimes shortcuts take a lot longer.

[zayd]

Originally Posted by skyguyscott

Sadly, no. By far, the most tedious part is fitting in the new floor under the shell. (unless you do a shell off, then it's easy, except for the part where you lift off the whole shell) I don't know any way to do this that does not first require you to pull out everything sitting on the floor you are replacing.

I see. The area is already cleared out, but it sounds like working in the new floor is the issue. Would it have to be done from the inside (in pieces, I assume)? Or once all the fasteners are removed/cut, could the old be pulled out from underneath the shell on the outside and the new replaced that way? Just want to understand where the difficulty will be so I can weigh my options. Also note that I am only removing the last piece of subfloor, which is roughly 4x8’ in my trailer.

Zayd

[skyguyscott]

Yes, either way can work. Cutting the floor into sections does help ease the installation, especially when doing it from the inside. You will, of course, want to make the cuts so the edges rest on a section of the frame underneath. The slight disadvantage to this is you now have a seam where water/air/gnats, etc can move (but you can seal it) and the seam isn't quite as structurally strong as one piece would be.

Because of the rounded corners, you'll need to use the old floor as a template, then position the new floor so it fits just right, and abuts tight against the existing sections (sure, easy with the shell off, but....man!)

After you take out the old floor, you can see if there is any frame issues to take care of. Coating the frame with POR 15 seems to be the consensus here on being the best way to protect the frame from corrosion, but it's not the most pleasant stuff to work with.

Going to all this effort only to install more plywood, IMHO is nuts. Plywood wicks moisture, warps, harbors mold, attracts bugs, rots and for what? So you can save a few hundred bucks, only to have to do the whole thing over again in another ten years when you are going to be even older? Put something down so that when water inevitably finds its way to the floor again, the water can't damage it, even if it freezes, stands there for a while, or steadily drips.

[bradt]

Here are some photos of the holes I cut. I realize this is not for everyone, but I thought it worked OK.



The idea is to remove the old bolts, and insert new ones from the bottom up. You can add washers and nut from the top thru the access hole and then tighten with a socket wrench. I planned the location of the hole to allow for the ratchet handle to rotate.
There were 3/8" bolts thru frame members and self tapping floor screws in other areas. Since no access to install self tapping floor screws, I used 1/4" bolts. I used all grade 5 bolts and nuts since they were strong and easy to work with.



You can see all the holes, one for each bolt or screw.





Holes are drilled out from below with a long bit. Once the new flooring is slid into place under the wall, the holes have to be drilled out again to pass thru the flooring and shims if used. I used 1/2" Coosa board and added 1/8" aluminum shims. I could drive the shims into place afterwards, so I had some wiggle room to get the flooring in place.







Once complete, I used 2" press in knockout plugs to cover the holes. I got black plastic onces, but there are all kinds to choose from.

Since they are all behind furniture and the dinette, the fact that they are there does not bother me.

I used Coosa board and spliced it in the middle over the extra wide center frame member. I replaced about 42" of floor instead of 48". This meant I had to cut down the width of the Coosa board a few inches and that is the strip in the center. So, all done with only 1 sheet of 4x8. Same would work with plywood. I fastened down the floor panels with self tapping floor screws, the super corrosion resistant type sold by etrailer. They require a pilot hole to be drilled first.

I hope you can see how this process works. I was pleased with the rate of progress and the results.

Brad

[zayd]

Originally Posted by skyguyscott

There is a small group of us here who passionately believe in using Coosa Board as a replacement subfloor; it is a composite material used in the marine industry that is just as strong and easy to work with as plywood, but only 2/3rds the weight and is virtually water-proof, mold-proof and critter and varmint-proof as well. Yes it is more expensive than plywood, which is undoubtedly why AS doesn't use it instead. But it is totally worth it, IMHO to avoid ever having to replace the floor ever again!

Scott & Tony -- are you using Bluewater 20 or 26? I'm getting a quote on 5/8" 4x10 Bluewater 26 (to eliminate the need for a seam). Minimum order is 5 sheets, but I suspect I won't find a shortage of AS owners in the midwest that would take a sheet or two.