Subfloor Installation/rust protection

I have a question about applying the rust protectant before doing your subfloor. I have a 2019 sprinter in very good condition. The rust spots are almost nothing and the paint on the floor is basically unscratched in most places. Do you paint the whole floor with it or just the high touch spots/ vulnerable areas? I see some builders recommend both ways but I’m not sure which route to go. To be clear, I’m definitely going to apply the anti-rust coating, it’s just the amount I’m going to use that is in question.


I hate answering questions with questions, but in this case I think it’s relevant…

Will your rust protectant protect it better than the original paint?

I believe I would base my decision on that answer…


"Be the reason someone smiles today!" ~ Van_Dweller

That’s my question too! lol

I feel like a complete coating on the entire floor is generally for older, very used vans with many rust spots. I would think that the manufacture’s paint is protection enough but then I see other people coating the whole floor regardless of rust spots and I’m confused.

I’m at that exact point, also with a Sprinter, and floor is in good condition. I’m going to grind the rust spots (back edge is the worst), rust treat those areas, then intending to put a coat of hammerite over the complete floor. I’m not convinced that it will add protection but I just like the idea of a continuous membrane (paint) over the whole area!