Underseal?

Hiya.
Well, Swampy is having a bit of a major refurb. Half of the floor was completely soggy, so I've spent today hacking up the soggy stuff to put some new ply down tomorrow.
My query is what should I put onto the underneath of the ply to use as underseal?
Thanks peeps
Kim

We used Tetraseal applied with an underseal gun. You could also use schutz. You can probably get them in brush on form as well.

if its WBP/marine grade ply then i wouldn't use anything as when it does get wet,it will dry out with out any problems.I used tetrosyl to replace the underseal that had come away exposing the OSB Board.