Using T1-11 siding- questions

[MushCreek]

I'm working on building my barn here in SC, and it will be sheathed with T1-11 plywood as the only sheathing/siding. I came up with a plan to keep the bottom edge further from the dirt, and wanted to get opinions. My plan would be to use maybe a 1X6 pressure treated at the bottom of the wall, overlapping the concrete slab a bit to keep the rain out. Then I would put Z-flashing over it, and then start my T1-11. I would space the plywood so the bottom edge could dry after a rain. I think I would need a backer block where the 1X6 and T1-11 meet to have something to attach the Z-flashing to. Does this sound like a reasonable improvement over just running the T1-11 down over the slab edge?

Also- when using a single layer of siding like this, How do you flash windows and doors? It is a barn, so minor leakage would be tolerable, but I'd like to keep the whole thing from rotting out too quick. Any experience?

Internet is sketchy here, so I might not respond for a while!

[Ernest T. Bass]

I'm no expert, but the PT starter board sounds like a good idea to me. Pole barns use a PT skirt down to the dirt all the time. You might want to fasten with deck screws to prevent cupping and apply a stain or something..

Some people may say to install the windows first and the T1-11 like siding, but I think if it were me I'd sheath first. I'd stick the windows on the outside with plenty of caulk behind the nailing fin and rip some trim to conceal it all. Prime all sides of the trim, and another bead of caulk after it's installed.. If the windows are gonna see a lot of rain, I'd also cut a groove/kerf at an upwards angle into the T1-11 above the windows as deep as possible and slip a rain cap flashing in (much easier to do before the windows are installed). G/L!

[BRUTAL]

PERSONALLY, I would use 4x8 sheets of hardi plank instead. a few $$ more, but then you dont need to worry. Then you can come back with either pine or cedar 1by to board and batten it for a barn look and to hide the seems. Youll be doing corners too and trimming the windows and doors so it would all tie in. You can use trim boards in Hardi plank also, but then those get alot more costly. i was going to use T1-11 siding too, but decided against it after thinking long term and the differance in cost. I bought all Hardi plank to side my 14x20 and hardi plank 1bys to trim windows and doors from Lowes for $600 with a 10% coupon you can pick up at the post office in Mover packs:)

[JRR]

Are Hardi-Planks recommended by the manufacturer to be used as sheathing?  I've done a wee bit of reading at their website, seems they usually show it going on top of plywood, OSB, or braced studs.  ??  May be OK for non-residential ... not sure.  I think they expect it to be used only as "siding".

[MountainDon]

Hardie does mention using their products over braced wall (diagonally placed) studs. I've seen one illustration of that on their instruction pages, all other show it being applied over sheathing with weather resistive barrier between. Maybe for a shed but I would not do that for a cabin or other residence myself. Hardie also illustrates it being applied over 1" maximum thickness sheet foam without sheathing. Personally I can't see doing that as that inch of foam will allow movement.

My thoughts are that since something like 7/16" OSB sheathing supplies so much more anti racking strength to a wall one is better off using the sheathing even if the code authority in the area might be okay with inlet braces.