Underside of PUP

Discussion in 'First Time & New Camper Owners' started by Tacoma_Jim, Nov 5, 2011.

  1. Tacoma_Jim

    Tacoma_Jim Member

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    As I got down to drain my tanks, I noticed the underside of the flooring is exposed. It is OSB ( Oriented Strand Board ) and appears to be totally raw. I know that rain from above won't damage it, but living in the Northwest, will I have problems driving in the rain and water kicking up underneath? Has anyone sealed their underside? And if so, with what?
     
  2. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    Thia question comes up often from newbies. The answer is that you are not suppose to seal it. The underside of the floor and the bunk ends is supposed to be left just as it is so it can breath and thereby expel moisture. If you seal it you will promote rot. I don't know about what other brands say in their owners manuals but Fleetwood/Coleman addressed this in theirs and included a support statement from Weyerhaeuser, the manufacturer of the OSB they used.
     
  3. Dusty82

    Dusty82 Active Member

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    This topic comes up at least a half dozen times a year, and there are always varying opinions. This is just my opinion and it's worth every penny you're paying for it, but I say leave it alone. Pup floors are left untreated to let the flooring breathe and dry completely should it get wet from above or below. Some will disagree with me, but to those people I say that all you have to do is take a look at the number of pups built in the 60s and 70s that are still on the road that have an untreated floor in them.

    There are exceptions to every rule, of course. You'll see threads here on The Portal about people replacing rotting floor sections. If you look a little deeper, however, those repairs are usually needed due to a leaking roof or roof seal - not because the floor rotted from the bottom up.

    Anecdotally, I can tell you that I've scrapped a 1975 and a 1978 Coleman pup within the last 18 months, and in both cases the floor was just fine. In fact, the floor from the 1975 is being used in another project.

    Just my 2ยข - I'd leave it be.
     
  4. Blkvoodoo

    Blkvoodoo Member

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    But.....

    What if a guy covered the underside with say, chicken wire ( real small mesh ) to attempt to keep rodents at bay, then maybe another cover of landscape fabric . lets the bottom breathe and controls some of the splash up from road spray.

    just throwing darts here, it's new, it still smells new ( and smokey ) and would like to keep it that way.

    need to find the LP leak before I cover anything though, wasted a full tank of LP in a week, not happy about that ( the tall guy with the beard left the valve open ) [:I] [8]
     
  5. Tacoma_Jim

    Tacoma_Jim Member

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    Thanks guys. That makes a lot of sense.
     
  6. RotnMom

    RotnMom Am I there yet?

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    Well crap...now I gotta go crawl under my pup to take a photo. I'm pretty sure the last time I was under there, the wood looked like it had been lightly spray painted...like an undercoating.

    Now, if only the rocks would warm up before I have to lay on it. [;)]

    [:D]
     
  7. Blkvoodoo

    Blkvoodoo Member

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    It probably is, I know mine is ( I was just under it 20min ago winterizing stuff )

    mine looks like they were scared to actually paint it, but just put a promise of color on it to make it look pretty

    the original question asked was one I asked not long after joining here or the other ( PUX ) board. don't remember which, and got pretty much the same response given today.
     
  8. RonJ

    RonJ Member

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    My 1982 Rockwood looks like it received a thin coat of black paint and still looks good. Maybe I should just give my roof a thin coat of paint [;)]
     
  9. Flyfisherman

    Flyfisherman New Member

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    Yeah, The Starcraft tech folks told me that lightly colored black paint on the bottom was actually a sealer put on when being built. They said the special sealant/preservative used was actually was clear but they added a tad of black coloring so it could be seen and then everyone knew it had been treated, from the factory to the dealer to the customer.
     
  10. mtnkube

    mtnkube Member

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    mine is also painted with a very light coat of black. I work at a paint store and can tell you that the amount of paint on the OSB(at least on mine) is not going to do any sealing of the wood. It is still able to breath. I personally will not seal mine because i like the idea of it being able to breath. if i seal the bottom then any water that gets on the top will not dry as fast.
     
  11. turborich

    turborich Active Member

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    I know that many folks are against sealing the underside, I am not one of them. I can see no reason to leave it exposed. My Jayco has a black sealant sprayed on it from the factory, my old Starcraft had aluminum covering the entire bottom.

    You can do as you wish but if it were me I would seal it with something to prevent rot. You read about rotted floors all of the time. How on earth does the untreated underside allow the camper to breath? There is vinyl flooring covering the wood anyways. I don't buy it one bit and think it's just a cost saving thing.
     
  12. Dusty82

    Dusty82 Active Member

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    It's your pup, do as you wish. I just know that floors in both of the 30+ year old pups I scrapped were in fantastic shape without any treatment at all. The TT that I scrapped, however, had the underside of the entire floor covered by a thin 1 piece aluminum sheet. That floor rotted from about the center back due to a roof leak. Water from the leak traveled down the framing and pooled on top of that aluminum sheet and rotted the floor. I think I took a piece of plywood about a foot square out of the entire rear half of that floor - the rest looked like chewing tobacco.

    Yes, you read about rotted floors all the time, but look a little further and you'll see that in the overwhelming majority of those cases, the rot was caused not by the floor being untreated, but rather from a roof leak, failed top seal, or some other water entry point.

    Having said that, if you can seal the entire floor - top, bottom, and all of the edges - then you'll probably be fine. Basically, you'll have to encapsulate it in whatever sealer you're going to use, but it is doable. Still, based on the number of 30+ year old pups still on the road with untreated floors, I have to ask, why bother?
     
  13. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    I left mine* exposed for three reasons: 1)The manufacturer of the wood product said to leave it exposed; 2) The manufacturer of the trailer said to leave it exposed; 3) The dealer that sells the brand said to leave it exposed.

    Since the OP owns a 2008 Fleetwood Tacoma the information I provided on Nov. 5th is reason to leave it exposed for him. If you want to get facts and make a decision based on them I recommend that you contact the manufacturer of your PUP and see what they say.


    *I'm speaking of my Fleetwood Yuma, which I owned for three years before moving to a TrailManor.
     
  14. scorp28

    scorp28 Member

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    I agree with leaving it exposed also. My 2 pups are 37 & 43 years old and both are original floors and both in great shape. I do have one question though that somebody might be able to answer for me. What is with the Poly Flex underbelly material that Jayco is using to wrap their floors with? Does anybody know what purpose it serves?
     
  15. PattieAM

    PattieAM New Member

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    Fleetwood/Coleman uses "Structurewood", which requires air to 'breathe'. Accordingly, one should not coat the underside of the PUP.
     
  16. turborich

    turborich Active Member

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    It wouldn't be an issue if you didn't live in the rain & snow. Don't you guys think the moisture is going to eventually damage the underside of the wood? Have you ever left OSB out in one rainstorm? You can toss it out because it swells.
     
  17. apachejeep

    apachejeep New Member

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    Ok, I'll have another take on this. My opinion, for what its worth.....I don,t have OSB on my popup, but plywood. When I first purchased the Apache, I noted the underside very dry. Went ahead and dry coat the underside with wood sealer. Dry coating to me means, dipping the paint brush in sealer, dabbing the brush on a cotton rag, then applying. The dry ply soaked it right up. Can't speak for OSB or the other opinions expressed, but I did not want to have dry rot. Of course I live in a dry climate , but take all the opinions, and do what's best for you. OSB may have a sealer within, so the Manufacturers recommendations are most likely correct. Myself, a lot of times I don't follow the rules..... But thats just me.
    Good Luck!
     
  18. LjohnSaw

    LjohnSaw So many fish, so little time...

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    Its interesting to see this topic come up so often. I've been on this board for about 5 months and I think this is the third go round.

    Just an observation - OSB is a bunch of wood bits, sprayed with glue and bonded together under high pressure. I would almost go as far to say each piece is encapsulated with glue. When I have used it in construction, it has a very waxy, slippery surface. My guess is it is the glue and it is pretty waterproof. While I have seen old pieces that seem to be swelled and somewhat loose looking, I think that is from exposure to the sun (UVs) rather than water.

    Now it being OSB, it does not really have an "end grain" to soak up water. It will take in some water from the edges but it's not going very far, unlike plywood.

    Just my [2C]
     
  19. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    What is so difficult for you about accepting what both the manufacturer of the wood product and the manufacturer of the trailer say?

    (BTW, I do live in a lot of rain and sometimes snow. When I sold my PUP after three years the bottom looked -- and was -- perfect.)
     
  20. turborich

    turborich Active Member

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    What is so difficult about you acknowledging that OSB swells if left out in the rain?

    If you want to leave it untreated then I could give a rats ass. I'm just stating the obvious.

    You wouldn't build the siding of your home with untreated wood, so why would you leave the underneath of your camper untreated?

    You refuse to think outside of the box. I'm sure the owners manual states that the ABS roof will last a lifetime too! [LOL] Is it going to hurt anything if somebody takes a proactive approach at extending the life of their floor? Why does it have to be your way or no way? If you don't want to seal the floor then don't! If you do then what's it going to hurt?

    Why do they sell Thompson's water seal?
    Why do people seal their wooden deck?
    Why do people seal their concrete?
    Why do people seal their cars paint?
    Why do people undercoat their cars underside?
    etc, ect, etc.
     

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