Decided to replace floor - best paint / sealant to use?

[Texas Torpedo]

I just started the process of converting my 7x16' V-Nose cargo trailer and while removing all the wall boards to add insulation I discovered there are a few leaks (purchased trailer used). No big deal but I felt some flex in one of the floor boards about the same time and got the itch to pull the one furthest back up.. It seems to be in fairly good condition but while I'm going wild with this conversion, I might as well replace all of them. This also gives me an excuse (access!) to do a lot of mods under the floor..

That being said, I know I need to seal / weatherproof the bottom side of the new floor. Is there a specific product that you all recommend?

Thanks,
David

[BC Cargo]

http://tnttt.com/album_ ... c_id=84979

The above link shows my frame after 6 months old, so you may need some type of rust preventative paint for this as well. I used the same paint brand (but different color) on the under side wood because it said it was good for wood too. You should be able to do both with one gallon and have some left over for the studs, etc. Here is a link to the finished underside.
http://tnttt.com/album_ ... c_id=84993

I also glued the floor down with some PL200...this sealed the edges. You may notice that without the floor screwed to the frame that the cross members flex a lot. I ran a extra strip of metal on the underside to act as a cross brace. You can also see I ran my wiring in a PVC pipe to protect it. There are some more pics of the flooring in my album.
Good Luck

[8ball_99]

I'd get some good treated plywood for the floor. I used the same stuff the teardrop guys paint the bottom of their tears with.. Its henry asphalt emulsion used on roofs. Probably any brand would work. Its for wood and metal. I just painted the under side of all the wood with it. I then touched up any spots on the metal that didn't have a good coating.. My trailer already had some kind or tar or asphault coating from the factory on the frame..

[vreihen]

Playing devil's advocate, I was told by my trailer dealer that you should *never* seal both sides of a plywood floor. He said that the plywood needs to breathe, and every rotten floor in a CT that he's ever had to replace was because the owner tried to prevent the wood from rotting by sealing both sides. Don't know whether to believe him or not, but the floor in my car hauler is raw plywood underneath and painted inside from the Featherlite factory.....

[8ball_99]

Playing devil's advocate, I was told by my trailer dealer that you should *never* seal both sides of a plywood floor. He said that the plywood needs to breathe, and every rotten floor in a CT that he's ever had to replace was because the owner tried to prevent the wood from rotting by sealing both sides. Don't know whether to believe him or not, but the floor in my car hauler is raw plywood underneath and painted inside from the Featherlite factory.....

I'm not sure if I would buy it. I know the teardrop guys on here have been sealing the under side of their trailers for a long time. Most of them aren't even using treated plywood. With mine I really had no choice cause I also insulated the floor. Thats the main reason I sealed mine.. I didn't want foam insulation up against the wood floor with out a good coat of sealer on the wood.
Lots of RVs setup for cold weather have insulated floors with plastic covering the underside of the trailer. They also have insulated holding tanks. Which would pretty much seal off the underside of the trailer also. Course they probably have carpet inside some of the camper to though.

[Texas Torpedo]

Thanks for the info everyone! Much appreciated as I will be working quite a bit this week on the underside.

[Larry C]

Playing devil's advocate, I was told by my trailer dealer that you should *never* seal both sides of a plywood floor. He said that the plywood needs to breathe, and every rotten floor in a CT that he's ever had to replace was because the owner tried to prevent the wood from rotting by sealing both sides. Don't know whether to believe him or not, but the floor in my car hauler is raw plywood underneath and painted inside from the Featherlite factory.....

Playing devil's advocate +1.....
I used to own a 25' plywood cabin cruiser. It was painted on the outside, and left raw on the inside. I was told the same thing, plywood needs to breathe and dry out by leaving one side uncoated. Also, I owned a Jayco Popup, it too had no coating on the underside.

I have been wondering about this for quite awhile. How much water does the underside of a trailer even see? What it sees dries quickly. The biggest problem is the plywood contact with the metal of the frame. If this area is protected from water staying between these surfaces, I think the open bare wood should not need any surface protection, which actually may be a cause of the rot.

How many very old plywood floored trailers have any coating on the bottom?
IMO the floor rot issues come from water getting into the walls through windows or doors and rotting the floors from the inside not the outside.

Not very scientific, just my opinion.....

Larry C