You don’t want to go out and do something crazy to your boat. When she needs a little tender loving care, you have to do something. Living on a budget makes it hard to call in a repair man for every issue but using the right materials can make a huge difference. Here is the start of a debate that’s currently going on about using pressure-treated plywood.
[wish2fish] posed an engineering question: I know we have discussed pressure-treated versus marine plywood many times. Some of the philosophy about not using pressure-treated lumber on a pontoon probably came when they used arsenic as a preservative. While watching a video about Harris FloteBote pontoons they specifically say they use pressure treated plywood.
[BobG] agreed: I’m guessing most manufacturers use pressure-treated plywood. I know Avalon/Tahoe does.
[Moser] offered his input: I follow some restoration forums too and the consensus there is to stay away from pressure-treated on aluminum boats. There is a chemical or electrical reaction between the wood and the aluminum. There are different types of pressure-treated plywood, some better than others, but most folks on the restoration forums stay away from it. I redid the interior on my Sea Nymph over the winter and used Auruco Exterior Grade plywood for my decks. I sealed it with three coats of polyurethane. If I had to re-deck the pontoon I would use the exact same stuff.
[jimrs] has been there: If they use pressure-treated plywood, you will find a membrane between the wood and the alum when you take it off. It’s thin but protects the alum from the wood. My neighbor just took his off and that’s what we found.
[PontoonMoose] shared his success: I used pressure-treated 5/4 deck boards to re-deck my pontoon when the floor gave up. I stripped everything down to bare metal, then coated all metal parts that the pressure-treated wood would be touching. It’s been re-decked for two years now. Two weeks ago I had to pull a board up to get to some wiring and I saw no damage to either the board or the metal. I bought the 5/4 deck boards about six weeks before I installed them and set them in the sun and rain and would turn them once a week. Part of it was to let them dry and shrink to size but also to let some of the treatments get bleached out. I put them down and now could not be happier.
Do you have personal experience to share? Or do you just want to learn more? Log on to the forums and search for the “Pressure Treated Plywood” thread to read up and see pictures of Pontoon Moose’s successful restoration project. The forums are located at