Osb longevity

[/pine]

If you really don't need marine plywood (no inner ply voids and made with resorcinol glue) an excellent alternative is exterior grade Douglas Fir plywood...

 

[s219]

I forgot to mention to check out Advantech OSB floor decking. It's made to really hold up to water/moisture when building new homes where you're at the mercy of the weather. We used it on our new home, which was open to the elements during super storm Sandy, and I was amazed how well it held up. I have seen product demos where they immerse it in water for a long time and it comes out OK. The only issue might be price -- I don't know what it costs, but it's surely more expensive than standard OSB. So for a non-flooring use, it might not be cost effective compared to other options.

 

[forgeblast]

Home Depot also has a product called smart siding, it is durable.

 

[Raspy]

At about 15 to 30 bucks a gallon for paint, it doesn't take much to make up the price difference to a marine grade of plywood that will last years and years without any paint. I never liked OSB as I always found that small pieces always de-laminate and turn into large splinters ready to injure you.

I don't think you are really talking about a true marine grade plywood. Just an AB grade with relatively thin plies. Marine grade plywood costs about $100. or more per sheet of maybe 1/2". Crezon (sp?) exterior grade sign plywood is also a nice choice. It is made to be outside and with a coat of paint will last a long time. But OSB will last a few years if painted carefully too. I agree with the splintering and failing edges if not treated right.

 

[SirReal63]

Marine Grade plywood is not treated in any way to resist moisture. As /pine indicated, it is a structurally strong plywood, but it will rot just like any other plywood, and just as fast. What makes it different is the way it is constructed, all inner plies are B & Better grade with no voids or overlaps. This makes it structurally strong and is a carry over from a military spec. There are not many uses for it anymore, except in boat building, (which was the original use). I spent my 30 year career in building products and forest products and sold a lot of it over the years.

I would second the HardiPanel, other than the weight, it is a superior product that will outlast the hunter. Skip the LP product, it is just hardboard siding that has a resin impregnated in it. Treated plywood is good, but tends to warp as it dries out and is subject to delaminating over time. Advantech and Smart Shield are resin impregnated OSB, not a true exterior grade product, they were designed to extend jobsite exposure and handle the occasional rain. It is also a bit expensive and doesn't hold paint very well. Painted exterior grade Fir is an excellent option, holds paint well, is fairly light and super easy to work with.

 

[buckeyefarmer]

fwiw, I used osb as siding on my shed 18 yrs ago, and it's still in decent shape. it's rotted at the bottom where it's real close to the ground, and plants grew up beside it. everywhere else, it's fine. It was unpainted for about 3 yrs, and then it got one coat of paint. It's not as bad as some make it out to be.

 

[EddieWalker]

I am going to build a few 8x8 deer blinds this year and in an effort to keep the prices down I was thinking about using 7/16 osb which is about 1/3 the price of standard sheeting. Just wondering if we paint the osb how long could we expect it to last?

Why 8x8? I built my deer blind that size and it was a mistake. My theory was to be able to hold four people and even spend the night in it. So far I've never had more then two people in it and the only time anybody spent the night in there, they started a fire outside the blind and scared away all the hogs that had been coming there every morning like clockwork. The biggest problem with a blind that size is you can't see out all the sides of it without getting up and moving to the other side. I have my favorite corner where I see the most from, but I never know what's going on behind me.

OSB is a fantastic material for creating sheer strength to a wall and holding nails for things like shingle and siding. It is much better then plywood of a similar size because it doesn't come apart like half in plywood does. It's cheaper then plywood too. I wouldn't use it for anything left unprotected, and paint isn't going to protect it for very long.

Zip System comes with a coating that lasts quite awhile, but the cost is more and I'm not sure how long it will last. Smart siding is also an OSB product that is supposed to last forever as an exterior siding. I use it under porches where it's protected from the elements because I'm not convinced it's as great a product as those selling it say it is.

Any and every plywood option out there is going to need constant upkeep to last. Do you want to keep painting it or build it and be done with it?

If you build it with OSB, wrap it with house wrap and it will last a year without any issues, then you can come back and cover it with some sort of siding. My favorite is Hardie lap siding. It's easy to install and it lasts forever. You can also use Hardie sheething, but it's heavier and harder to work with.

And of course, there is always pressure treated plywood. I rarely use it for anything, but for this, it's probably the best value you'll find for something that will last and not require much time to build

Eddie