Two materials, and they are not two versions of the same product. One hangs and one is fastened. One is cut with a knife and one is cut under dust control. One arrives in cartons a single installer carries. Here is the comparison from the install side.
Weight and handling decide the crew before the colour does
Fiber cement is a cement-and-cellulose composite. It is dense, it is heavy by the square, and a long plank is a two-person carry, not because one person cannot lift it, but because a plank carried at one end flexes, and a flexed plank cracks. Long runs go up off staging or a lift rather than off a step ladder, and the delivery has to land somewhere it can be stacked flat, off the ground and covered, because a wet stack is heavier still and it moves.
Vinyl arrives in cartons, one person carries them, and a bundle can be walked around a house without a plan. That difference shows up as labour hours long before it shows up anywhere else, and labour is the larger share of a siding price.
It carries into the parts of the job nobody quotes out loud, too. A second storey in fiber cement wants staging rather than ladders, and staging wants a place to stand and a way in around fences, air-conditioning units and planting. The tear-off comes off heavier as well, so the container is sized differently. Access is a real line on a fiber cement bid and close to a rounding error on a vinyl one.
Substrate: what each material needs under it
Both want the same wall behind them: a weather-resistive barrier lapped shingle-fashion, flashing at every head, sill, penetration and roof-to-wall junction, and a nailable substrate. Neither material is a substitute for any of that.
The difference is flatness. Fiber cement is rigid and does not conform, so a wall out of plane shows as a shadow line along every course, and the remedy is furring before the first plank rather than adjustment during. Vinyl hangs, and it telegraphs the same defect as a wave. Same wall, two symptoms.
Both carry clearance requirements the manufacturer publishes: to grade, to roofing, to decks and to horizontal surfaces. Fiber cement sitting in ground contact wicks, and that is the single most common cause of the bottom-course failures we get called out to look at.
Fastening: the two materials are opposites
Vinyl hangs
A vinyl panel is not fixed to the wall. It is hung from a nailing hem and it has to stay free to move along its length, because the panel is measurably longer on a hot afternoon than it was on a cold morning.
- Drive the fastener in the centre of the slot, square to the wall
- Leave the gap under the head that the manufacturer publishes; the panel has to slide beneath it
- Leave the specified end gap where a panel enters a receiver or a corner post, sized for the temperature on the day it was hung
- Never fasten through the face of a panel
- Never seal a panel end into a J-channel; that is the detail that turns ordinary thermal movement into a permanent buckle
- Lock the starter course properly, because every course above inherits that line
A nail driven tight is the most common vinyl defect in the trade, and the wave it produces is almost always blamed on the panel.
Fiber cement is fastened
A plank is fixed, not hung. Depending on the product and the exposure, the instructions call for blind nailing at the top edge or face nailing, with a fastener reaching a specified penetration into framing or a rated nailable sheathing.
- Set the fastener flush, not countersunk. An over-driven head crushes the board, loses holding power and dimples the face where it did it
- Pre-drill near ends and edges where the instructions call for it
- Use the corrosion class the manufacturer specifies: hot-dip galvanised or stainless. The wrong fastener bleeds rust down a light-coloured wall inside a season
- Treat butt joints the way the installation instructions treat them, with joint flashing behind the joint where it is specified. A bead of sealant is not a substitute for a piece of metal
- Seal cut ends before the plank goes on the wall
Those instructions are a document, not folklore. Fastener spacing, nailing pattern and corner-zone requirements come out of it and belong on the scope sheet where the crew can read them.
Cutting: dust is the difference, and it is a scope item
Cutting fiber cement releases respirable crystalline silica, which puts dust control inside the scope of the job rather than at the end of it. OSHA’s respirable crystalline silica standard for construction governs how that cutting is done, and the practical controls are the ones a good crew already works to: shears wherever the cut allows, because shearing produces almost no airborne dust; a dust-collecting circular saw with a matched vacuum and a diamond blade where a saw is required; cutting outdoors and downwind of the house; and respiratory protection where the method calls for it. Dry-cutting fiber cement with a standard blade in a closed garage is the version that should never happen, and it happens.
Vinyl cuts with tin snips, with a fine-tooth blade run in reverse, or by scoring and snapping. The trap there is temperature: cold vinyl is brittle, and a panel that would snap cleanly in July cracks in January. Score deeper, warm the panel, and expect more waste on a winter job.
On a tight lot this is a neighbour conversation as well as a safety one, and it belongs in the pre-start briefing rather than in an apology afterwards.
Finish, colour and the repair you will make in year seven
Vinyl carries its colour through the extrusion. It cannot peel and it never needs paint; the trade-off is that the colour is fixed for the life of the panel. The risks are fade on a hard elevation, and matching a colour that has aged a decade or gone out of production when a panel finally needs replacing.
Fiber cement comes prefinished or primed for field paint. That is a repaint cycle you are signing up for, and it is also why a damaged plank can be made invisible: cut it out, replace it, prime the cut ends, touch in the finish.
Heat deserves its own sentence. A dark vinyl on a hard west elevation is a decision that cannot be reversed, and concentrated reflected sunlight off a neighbouring low-emissivity window can distort a vinyl panel in a way it will not distort a cement one. Where that geometry exists on a lot, it changes the material recommendation for that wall specifically rather than for the house.
The repair unit differs too. A vinyl course unlocks with a zip tool and a single panel comes out. A fiber cement plank is cut out and replaced, which is a longer job with more preparation around it.
Side by side, from the install sheet
| On the job | Vinyl | Fiber cement |
|---|---|---|
| Handling | Cartons, one-person carry | Dense planks, two-person carry, stacked flat and covered |
| Substrate demand | Nailable and reasonably flat; telegraphs waves | Nailable and flat; shows plane errors as shadow lines, often needs furring |
| Fastening | Hung from a nailing hem, centre of slot, head standing off | Fixed; blind or face nailed to a specified penetration, set flush |
| Cutting and dust | Snips, reversed fine-tooth blade, score and snap | Shears or a dust-collecting saw with a vacuum; silica controls apply |
| Movement | Significant along the panel with temperature; end gaps are mandatory | Dimensionally stable; joints handled by flashing and detail |
| Finish system | Through-colour, no repaint, colour fixed for life | Prefinished or field painted, repaint cycle, fully recoatable |
| Repair unit | One panel, unlocked with a zip tool | One plank, cut out and replaced, ends sealed and touched in |
| Where the cost sits | Material-led; installs fast on a sound wall | Labour-led; crew size, staging, blades and dust control |
So which one goes on the wall
The order we actually decide in. Exposure and any ignition-resistance requirement at the address come first, because that can remove a material from the list before anything else is discussed. Then substrate condition, because a wall that needs furring changes the labour on one material more than on the other. Then the finish appetite, because a repaint cycle is a real, recurring cost that a household either wants or does not. Then budget, understanding that the gap between the two is mostly labour rather than material.
Colour is the last question, not the first. Both materials will do most of what a colour chart promises. Neither will forgive a fastener schedule improvised on the wall.
The material pages carry the profiles and the brands we hang: siding and fiber cement.