JohnnyC wrote:

I am putting fiber cement claps on a small building. I've seen two
ways to do the corner boards. Either put the corners on the building
first, then butt the siding -or- put up the siding with the corner
boards on top of the siding.

Do you have a preference? The installation instructions for the
hardiboard show it both ways. I was thinking of putting the corner
boards on top of the siding would be a lot easier because I wouldn't
have to be so precise with the cuts on the claps.

Cornerboard on top of siding
----------------------------
Advantages:
* Easier measuring of siding.
Disadvantages:
* Ten times as much caulk.
* Harder to get the cornerboard straight.

Siding butted to cornerboard
----------------------------
Advantages:
* Lots less caulking.
Disadvantages:
* You have to be careful measuring.

Suggestions
-----------
* Put the cornerboards on first.
* Be sure to put factory ends together in the field (where two pieces
of siding butt up to each other). The joint will be prettier.
* Get those butt joints nice and tight.
* Leave just a little space for expansion, no more than 1/8", between
the siding and the cornerboard.
* Don't align the top edges of adjacent pieces. Hold a straightedge
under the bottom edge of the siding to align the new piece to the one
already on the wall. The width varies just a little, and the bottom is
what will be visible.
* Caulk all the vertical joints. Don't caulk the bottom edges--water
needs a way out.
* Rent or buy the scissors to cut the HardiBoard. The dust from sawing
it is awful.

--
Steve Bell
New Life Home Improvement
Arlington, TX