Unfortunately,
this material eats blades alive. For example, if you cut fiber cement
all day you will need 2 or 3 blades a day to maintain a high quality
cut.
In addition, cutting fiber cement is very dusty. Protect your lungs
with a respirator. (A warning is printed on each Hardiplank bundle:
"Caution: This product contains silica, which has been known to
cause lung damage; use proper respiratory protection." Also wear
ear plugs. My little brother is the sawman for our outfit. He found
a lightweight dust mask called Dustfoe 66 at Highland Hardware in Atlanta
which works well.
The instructions say you can cut Hardiplank with a special knife, but
we found it did not work very well. The knife scribes a line, then the
siding is snapped, similar to how Plexiglas is cut. The edge is not
as clean nor as smooth as a saw cut.
Also, I must warn you that cutting Hardiplank is very hard on saws.
A saw used on Hardiplank won't be much good at fine cutting wood after
a house or two. The lumberyard believes the dust gets into the saws
and wears down the bearings. We have a saw that is used only for Hardiplank
and it is never used to cut wood. Keep this in mind when pricing a fiber
cement job.
Nailing
Nailing Hardiplank is similar to nailing other sidings-it can be either
blind nailed or bottom nailed. We prefer blind nailing everywhere possible,
and since we are old fashioned, we use hammers. I know some will disagree,
but this product looks best when hand-nailed. I have found power nailers
to either overnail or undernail, especially over foam sheathings. If
overdriven, the nails will compress the underlying foam sheathing, giving
the siding a wavy look. Foam sheathing is desirable from an energy standpoint,
but harder surfaces such as plywood and oriented-strand board (OSB)
are much easier to nail into and make for a better looking job.
One way to get the best of both worlds is to use foam sheathing and
then nail a 2-1/2-inch plywood strip nailer on each stud. This is called
a vented rain screen. Not only will this give you a better, stiffer
surface to nail to, but it will ensure long-term protection of the materials
behind the siding. If water does get behind the siding it can drain
away or dry out in the gap created. If you are using wood sheathing,
most manufacturers recommend using building paper under the siding and
corner boards to prohibit wood rot.
To blind nail we use 3-inch roofing nails. The large heads of the nail
help force the siding flat against the wall and close most gaps where
the siding laps the preceding piece. Before handing up a piece, my brother
would scribe a line with a combination square 1-1/2 inches from the
top, which shows just how far down to nail. The lower down you nail
the fewer gaps you will have. You can also use the line as a guide for
the next piece, although its a good idea to chalk a line about every
3 runs or so to keep things straight.
You only need pilot holes at the ends. Drill pilot holes a little smaller
than the nail shank to protect the corner. We also pre-drill a hole
when we are forced to bottom nail. When a nail is driven through an
undrilled place, the nail will bust out the backside, like a shotgun
blast, blowing out so much material that the nail really doesn't have
a lot to hold to. It won't take much to pull the piece loose. Pre-drilling
prevents this problem. Yeah, it takes a little longer to do it this
way, but you won't have to fool with loose siding and unsightly holes
later on.
When we nail on the bottom, we use number 10 galvanized screws or ringshank
nails. Don't overdrive them past the surface- aim for flush or maybe
a tad proud of the surface. To keep from having to nail at the ends
at some boards, you can use what is called preformed metal joints. Use
them when the siding breaks between the studs. They do increase the
speed of the job somewhat, but I really don't like the look, nor the
fact that the joints are not as stable, which makes caulking difficult.
In this case, putting Hardiplank over foam does make working the joints
a little easier when you don't have to worry about compressing the foam
at the joints.
— Jim Buchta, "Fiber-cement siding products gain popularity", www.startribune.com