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

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croy

On Mon, 28 Sep 2020 10:58:48 -0700, croy
wrote:

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


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.

On 9/28/2020 1:58 PM, croy wrote:
Is OSB a good choice for exterior shed siding (painted)?

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.

On Monday, September 28, 2020 at 1:58:59 PM UTC-4, croy wrote:
Is OSB a good choice for exterior shed siding (painted)?

--
croy

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.

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.

On Mon, 28 Sep 2020 10:58:48 -0700, croy
wrote:

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

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