A coil nailer with good depth adjustment is the tool of choice for nailing fiber-cement siding. After trying guns from several manufacturers, I settled on Hitachi's NV83A2, which has a precise and reliable depth-of-drive adjustment.
Even using depth adjustment, I have to turn the air pressure down to avoid overdriven nails. I usually start at around 80 to 85 psi, then vary the pressure depending on the type and thickness of the sheathing and how many layers of siding I'm nailing through.
Overdriving is a big issue with fiber cement: Drive a nail too deep and you cut through the facing, weakening the siding and leaving a deep hole that's difficult to fill. Setting nails by hand is quicker than trying to fix ones that are overdriven. In visible areas where I want the job to look perfect — such as around the front door — I set the depth so the heads are a little proud; then I set them by hand.
I use a 4 1/2-inch angle grinder fitted with a sanding disk to smooth out butt joints, elevation mismatches, and rough edges of trim. A 36-grit disk works well for general material removal; 80 grit is good for final smoothing. The sanding disks don't last very long, but even after they're too dull for fiber cement they're suitable for softwood. I always wear a respirator with a HEPA filter when I'm sanding.
I have an all-terrain forklift with a workbasket that I consider invaluable for installation. It holds all my tools and about 100 shingles at a time. Luckily, the coastal areas where I build are relatively flat and there's usually enough space to reach all sides of the house.
An all-terrain forklift with a workbasket holds tools and siding and provides a safe elevated platform.
When the forklift can't get access, the author uses pipe staging.
Hiding Face Nails
I caulk every exposed nail with latex caulk. Most folks just dab the hole with a tube of caulk and then smooth the blob with their finger. Coil nails often leave a small piece of collation wire that can prick your fingers, so it's a good idea to hammer down any protruding wires as you go along. There's no need to worry about the wire rusting; it's stainless.
For smoothing the caulk, I have a plastic auto-body spreader — the kind used for applying Bondo. This tool vastly improved my caulking: It produces a smooth finish that makes the nails almost invisible when painted. It also saves a lot of wear and tear on the fingers.
A Bondo spreader is ideal for pushing caulk into holes created by face-driven nails.
Surprisingly, the spreaders work great on wood-grain siding, too — I just hold them at a right angle to the grain. Since they're so cheap, I always carry an extra in my toolbelt in case I drop one from the scaffold.
Most fiber-cement siding manufacturers produce shingles, and I've used these on a few houses. They're expensive, though, and come in limited patterns and exposures. Plus the shingle material can be extremely brittle.
After a while I figured out that making make my own shingles with siding scraps cost me about the same as buying manufactured ones. At first I used them only for gable details, but my customers liked the look so much I now put decorative designs on other parts of the house.
I make the shingles out of either smooth or wood-grain lap siding, depending on the customer's preference. I use different widths of siding so that I can get different shingle widths without having to rip material on a table saw. In general, fiber-cement siding has a 1 1/4-inch overlap, so 4-inch-exposure lap siding measures 5 1/4 inches wide, which is a good shingle size.
The length of the shingles depends on the exposure you want and the complexity of the decorative cuts. Because we get a great deal of wind-driven rain on the coast, I usually use "three-ply coverage," which means there are three layers of shingles on the wall at any point. This guarantees proper overlap when I have different widths or fancy cuts mixed together in complex designs.
A rule of thumb for three-ply shingling is that shingle length should be three times the exposure. Since I like a 4-inch exposure, most of my shingles are 12 inches long. With plain (square-butt) shingles in more moderate climates, two-layer coursing should be adequate. With two-layer coursing, shingle length should be twice the exposure plus 2 inches.
Cutting. I cut the shingles to length with a 12-inch chop saw mounted on a homemade stand. Since each piece of siding weighs about 15 pounds and I normally cut five 12-foot pieces at a time, the stand is very sturdy. An angled stop block prevents dust buildup, which would otherwise cause the shingles to get progressively shorter. The number of siding pieces that can be cut at once is typically determined not by the saw's capacity but by the amount of weight that can be slid along the table.
The author's saw stand is sturdy enough to support up to five 12-foot lengths of lap siding — a good 75 pounds of material.
Stops made from wood scraps can be quickly screwed to the top for repetitive cuts.
Once the shingles are cut to length, the pattern can be cut. This is usually done with a stop block and with the saw set at an angle. If the points on diamond shingles exceed the maximum angle of the chop saw, I use a jig to hold the shingle perpendicular to the fence. I generally cut 10 shingles at a time because that's the maximum number I can get my hands around; also, using stacks of 10 makes counting easy.
After the blanks are cut to length, shingles are given diamond points and diagonal cuts on the miter saw.
A simple jig screwed to the saw stand holds a stack of shingles perpendicular to the fence when the angle exceeds the saw's capacity.
The final step is to ease the bottom edge of the shingles, which I do with an angle grinder and an 80-grit sanding disk.
Single edges are eased with a small angle grinder equipped with an 80-grit disc. The tool is enclosed in a plywood box; a large nail holds down the paddle switch.
One person can easily make 1,500 to 2,000 shingles in a day; I find that it's a good task for a helper or a less experienced crew member.
Matt Thompson owns Thompson Construction in Bokeelia, Fla.