In article 24fb9f2c-34a1-4a2a-8610-000b24b2dbb9
@j24g2000yqa.googlegroups.com, says...

We are planning construction of a garden shed to store garden tractor,
yard tools, and "stuff" (and regain use of my garage shop). We are
considering Smart Siding, Hardi Panel and T-11 (T1-11). Like the
looks of T-11 but have been unable to find pressure treated siding
used on some factory built buildings.

Is the siding going to be in ground contact? If not you don't need
pressure treated. Paint all exposed surfaces (that's top, bottom,
edges, and outward-face) before you put it up, use proper Z-flashing
properly gapped along the top, and keep it painted and it should last
longer than you will.

The Hardi panel looks good but their installation instructions require
a moisture barrier. This is a utility building and the siding will
also serve as sheeting. No interior finish. Will the cement fiber
panel hold up to long term use without sheeting and moisture barrier?
I have used a product similar to Smart and the building looks good
after 25 years but there is concern with Hardi.

The moisture barrier is not there to protect the hardi-panel, it's there
to protect the structure behind it. Hardi-panel is much like concrete--
it can hold and pass a remarkable amount of water. Having structure in
contact with it with no moisture barrier can result in the edge of the
structure in contact with the hardi-panel being kept damp and rotting.
Since it's covered by the hardi-panel you won't be able to tell by
inspection that it's rotting and your first notice may be when the shed
falls down.

Note that you can combine hardi-plank and t1-11 to good effect--if the
shed sits on grade the lower edge of the t1-11 will be closer to the
ground than is desirable--keep it painted and it will be fine but you
have to keep on top of it. If instead you put a foot or so of hardi-
plank at the bottom with aluminum flashing behind it, then a z-flashing
and t1-11 above, you'll end up with a pretty durable installation that
doesn't need much maintenance.


Any Experience?

RonB