Purchased an enclosed car trailer and interested to see if anyone has waterproofed the underside wood exposed to the elements. I live in Florida and rain and water on the roads is a constant problem in the summertime. I see there is some type of treatment on the wood but looks weak. Has anyone tried Flex Seal or something else to help preserve the wood or see issues with sealing?
Todd
No matter what you spend on enclosed trailers they are all pretty cheaply made. For mine I just sprayed the underside with Thompson water seal and hit it again every couple years. Seems to be working because it's still good and it's parked in the grass most of the time. Bigger issue is to constantly check for roof leaks.
Quote from: aboss4tg on February 12, 2026, 05:45:22 AMPurchased an enclosed car trailer and interested to see if anyone has waterproofed the underside wood exposed to the elements. I live in Florida and rain and water on the roads is a constant problem in the summertime. I see there is some type of treatment on the wood but looks weak. Has anyone tried Flex Seal or something else to help preserve the wood or see issues with sealing?
Todd
Once I was certain it was 100% dry and the humidity level in the building I had the trailer is was below 50%, I hit my original 1996 Hallmark 20' enclosed car trailer with a truck bedliner out of a spray can. The modern equivilent would be Herculine or Raptor.
Remember that like undercoating any coating will attempt to seal out the elements (where supports are located its going to be difficult to do 100%) but it also traps any moisture that does get into the wood promoting rot.
Hi to all,
Years ago we discovered a product called Penetrol made by Flood. Works just like they claim, and you can paint over it. I kinda like the Thompsons water seal idea as well, I think any bed liner type spray would only trap moisture. Might be worth talking with a person that specializes in wood/marine
And get their opinion.
R.R.
Appreciate all the response and will check into a few options described. I understand the concerns with a complete seal and trapping moisture, but my biggest concern is the front panels as past trailers have usually leaked, and the wood was rotten and had to be replaced.
Todd
I solved that problem by purchasing a Featherlite. I should've done it the first time.