Replies

1. 
   esch5995 | Jan 14, 2022 07:49am | #1

   I would not recommend it it will delaminate pretty quickly. No exterior finish lasts for long.

2. 
   john_c2 | Jan 14, 2022 08:39am | #2

   No no no no. Interior plywood will disintegrate outdoors. Doesn't matter what you do to it.

3. 
   elmaduro | Jan 14, 2022 11:31pm | #3

   You can go up a few price points and use marine grade plywood & finishes. Take a stroll through a marina and you’ll see this combo holding up well.

4. 
   rob_ss | Jan 15, 2022 04:45am | #4

   As others have said, no. Wasting your time and money. Don't even bother with exterior or marine ply - neither are intended to get wet that often and will look crap regardless. They go grotty round the edges fairly quickly.

   That having been said, paint is excellent protection and an exterior grade ply painted with 2-3 coats of something thick should last a good few years.

   What works REALLY well is treated lumber.
   I buy kiln dried outdoor framing lumber. It's expensive (OTTOMH about 30% more than a standard 4x2) and rip into strips which you can use to make patterns. I've even made outdoor giant kumiko.
   You may have to pick through the pile to get relatively knot-free bits as strips will break at knots, or kink, but they do last for many years.

5. 
   eddo234 | Jan 15, 2022 11:07am | #5

   I try to avoid chemically treated wood if there are safer alternatives, and there are. White cedar, cypress, and redwood come to mind immediately, redwood and cypress being more expensive than cedar. I use white oak, which is also excellent, but that’s because I have lots of it on my land that I cut and saw myself.

6. 
   user-1118538293 | Jan 15, 2022 01:10pm | #6

   Some of the medium to low (BC & lower) grades of exterior plywood sold at the box stores have gotten so bad in my experience that they are not holding up at all outdoors even with paint. Delaminating plies most often, and even if protected from water, it seems the thermal cycle of the seasons and night and day is enough to make them self-destruct.