About a month ago we built a small 8 foot handicap ramp out of pressure treated plywood. Didn't treat it with anything. We had a lot of rain. Noticing a long of cracking going on along the vertical plane.
Also made side barriers using plywood. The porous sides face horizontally. I'm getting a bit of warping already. Need to seal off the top. I have some door weather strips I'm going to seal off the openings.
Found a can of Minwax Indoor/Outdoor Helmsman Spar Urethane in the cellar. I was thinking of spraying it over all the surfaces. Probably give it a few coats. Would this be the way to go or should I apply something else and/or use a brush?