OSB for Shed Siding (?)

[croy]

Is OSB a good choice for exterior shed siding (painted)?

[hubops]

Most people think that it looks ugly. Painting will involve re-painting, every .. ? .. years. Depending on the size of the shed - board & batten might satisfy most people's esthetics. It's what I did for a few small garden sheds, over the years at different homes. My neighbour just replaced a large tin garden shed < ~ 14 ft. x 10 > that was on a nice concrete slab with a board & batten shed that stands a few feet taller and it looks & functions great. John T.

[Ed Pawlowski]

Be sure to paint the edges, that is the most vulnerable area. See below.

OSB's other moisture challenge has to do with dimensional stability - in other words, OSB can irreversibly swell, especially at the edges, when it gets too wet. This is not a decay issue, but swelling can cause other difficulties in construction. ... In addition, OSB is bonded with waterproof adhesives.

[Theodore]

OSB is prone to moisture absorption and swelling. You'd have to paint all 6 sides with oil-based paint to help keep that from happening. I would not do it, unless you want to patch in perpetuity. As an alternative, I just built a shed (9x16) last year and used 19/32" thick T1-11 siding. I chose the thicker panel because the thinner one (11/32") felt like I'd punch through if I accidentally hit it while parking the lawnmower or something. I painted two (2) coats of white oil based primer ("Zinsser Cover Stain 1 gal. White Oil-Based Interior/Exterior Primer and Sealer" from Home Depot or Lowes) on outside and 4 edges, and 1 coat on inside. Oh, and the whole thing is min 9" off the ground, built on concrete sonotubes, to keep the splashback from the ground/soil from rotting out the bottom of the facade or structure. And, I included Z-channel metal flashing on the panels at gable ends, also to help protect against water entering an edge. Looks beautiful after one northeast winter, and is built like a tank. My method is definitely not as cheap as using OSB, but I'll be living here for quite some time and wanted it done once and right, without regrets.

[Theodore]

to be clear: I painted two coats on outside and 4 edges OF EACH PANEL, and 1 coat on inside OF EACH PANEL. It took quite some time, but again, I've _no_ regrets.

[gfretwell]

It is better as a base for some kind of siding with a good vapor barrier and flashing to route water away.