Having made a relatively expensive mistake, I’m looking for some advice…
I replaced a 12mm, plywood ramp on a horsebox, the old ramp was six years old and was only rotting as the rubber matting had ripped allowing water underneath.
I used ‘standard’ (C grade) 12mm WBP ply, and painted it in £100 worth of granulated rubber paint. (Rubber matting was around the same price)
First few times the horse was loaded it would creak and crunch a little, six months later its gone spongy and is breaking up. Its sodden with water and lost all strength. I’d painted the front with this rubber paint and on the advice of the timber merchant, painted the reverse side in some old gloss paint as apparently I shouldn’t paint just one side.
So, replacement wise, should I use Birch Ply? Marine Ply? Wikipedia says Marine ply isn’t suitable for high moisture environments?! The ply obviously wasn’t strong enough in the first place, regardless of the moisture issue, but the stuff that I removed did the job fine and that was 12mm. I’m going to see if I can squeeze 18mm ply onto the ramp but not sure if it will increase the depth too much and prevent the ramp from closing.
Thanks for any help! Don’t want to make another mistake as its a huge side loading ramp that is about 2 metres square so takes two 8×4 sheets and is several days work!