OSB3 will last for years without any protection. Vertically mounted (boarded up windows and doors for instance) do so; I've had OSB3 (it had had a couple of years over a window) covering a water butt. It's horizontal (obviously), rather humid underneath, doesn't drain and gets no sun for several months. It's been there for >15 years and is still sound (18mm thick) although sagging slightly - it does have several kg of washing basket on it sometimes, so that might explain the sag.
Have fun finding that too. Everything seems to be water-based and OSB manufacturers no longer seem to pre-seal the cut edges of OSB any longer
You mean resin on its own? Not together with cloth or strand glass matting?
I think I would be more inclined to use simple (single pack) polyurethane varnish. How weatherproof does it need to be? Does it see direct sunlight, or rain and gales straight off the Atlantic?
The enemy is cracking; does it get bent or see wide temperature ranges? I'd generally think of ply as having better life than OSB, especially proper marine (WBP) ply although that is much more expensive. But if you are not too worried about appearance OSB is not too bad.
I didn't even think of that and the longevity is excellent. Not sure what I'd use, BFLN! When I re-roofed the 'barn' (local name for brick-built shed, to differentiate it from wooden sheds, so not anywhere near Yorkshire's standards) I used 9mm OSB3 and put on a solvent-based preservative that's water-repellent for about a year before putting on the roof. Has the advantage of providing a 'ceiling' that is painted white to improve lighting. Too soon to tell how it'll last but, extrapolating somewhat, it'll outlast me!
As title - will it work?
The boards (4ft X 2ft) will get wet (but not immersed) I want to make them last s few months at least...
If so I have never had need to use fibreglass resin etc - any gotchas?
"When used externally all faces and edges should be treated with an appropriate preserver"
Finding what?
Concrete shuttering that my car will run on....
Appearance is unimportant.
Tried paints & bitumen, the edges start delaminating first...
Have something to add? Share your thoughts — no account required.
Ask the community — no account required