Siding Material Calculator

Vinyl vs. Fiber Cement vs. Wood vs. Engineered: The Trade-Offs

Each siding material targets a different point on the cost-durability-appearance spectrum. No single material wins in every category, so the right choice depends on your budget, climate, and how much maintenance you are willing to do.

Vinyl siding dominates the market by volume — roughly 30% of all US homes have vinyl siding — because it is cheap, easy to install, and maintenance-free. The material costs $1.00-$1.50 per sq ft and installs at $2.50-$5.00 per sq ft including labour. It never needs painting, resists moisture and insects, and comes in dozens of colours. The drawbacks are visual quality (vinyl looks like plastic because it is plastic), limited repairability (a damaged section often requires replacing the entire course), and vulnerability to extreme heat (vinyl warps above 160 deg F, which can happen on dark-coloured siding in direct sun against a south-facing wall).

Fiber cement (James Hardie, Allura, CertainTeed) is the premium choice for homes where appearance matters. It looks like real wood clapboard, resists fire (non-combustible), resists rot and termites, and holds paint for 15-20 years between repaints. The material costs $2.00-$3.50 per sq ft and installs at $6.00-$12.00 per sq ft. The downside is weight and brittleness — fiber cement planks weigh 2.5 lbs per linear foot for 8-1/4-inch exposure, and they crack if dropped or bent. Cutting produces silica dust that requires a respirator and dust control.

Wood clapboard (cedar, redwood, pine) is the traditional American siding material. Real wood has an authenticity that no manufactured product replicates — the grain, texture, and way it weathers are unique to each board. Cedar and redwood resist rot naturally and weather to silver-grey without treatment. Pine must be painted or stained and needs re-coating every 3-5 years. Material cost is $3.00-$5.00 per sq ft; installed cost runs $8.00-$15.00 per sq ft. Wood siding lasts 40-60 years with proper maintenance — potentially the longest lifespan of any option.

Engineered wood (LP SmartSide) offers wood aesthetics at a lower cost than solid wood, with better dimensional stability and rot resistance. It is made from wood strands bonded with resin and treated with zinc borate for termite and fungal resistance. Material cost: $1.50-$2.50 per sq ft. Installed: $4.00-$8.00 per sq ft. The 50-year substrate warranty is strong, but the product must be painted (it has no natural weather resistance) and the bottom edges must be kept above grade to prevent moisture wicking.

Siding Pricing and Accessory Breakdown

A complete siding job requires more than just the siding panels. Accessories (starter strips, J-channel, corner posts, undersill trim, soffit, and fascia) add 15-30% to the material cost. Prices as of March 2026, US national averages.

| Component | Vinyl | Fiber Cement | Wood | Engineered | |---|---|---|---|---| | Siding per sq ft | $1.00-$1.50 | $2.00-$3.50 | $3.00-$5.00 | $1.50-$2.50 | | Starter strip per lin ft | $0.40-$0.60 | $0.50-$0.80 | N/A (first course) | $0.50-$0.75 | | J-channel per lin ft | $0.30-$0.50 | $0.75-$1.25 | N/A (wood trim) | $0.60-$1.00 | | Outside corner per piece | $10-$20 | $25-$40 | $3-$6/lin ft | $20-$35 | | Drip cap (over windows) | $0.25/lin ft | $0.50/lin ft | $0.75/lin ft | $0.50/lin ft | | Housewrap per sq ft | $0.10-$0.15 | $0.10-$0.15 | $0.10-$0.15 | $0.10-$0.15 | | Labour per sq ft | $1.50-$3.00 | $3.00-$5.00 | $4.00-$7.00 | $2.50-$4.50 |

Housewrap (Tyvek, Typar, or equivalent weather-resistive barrier) is required under all siding types by code (IRC R703.2) but is often installed before the siding contractor arrives. If not, add $0.10-$0.15 per sq ft for material and $0.25-$0.50 per sq ft for labour. Housewrap must lap correctly (upper courses over lower, like shingles) and be integrated with window and door flashing to create a continuous drainage plane behind the siding.

Measuring Exterior Walls: Gables, Bump-Outs, and Dormers

Exterior wall area is harder to measure accurately than interior walls because of gable ends, dormers, bay windows, and multi-level roof transitions. A systematic approach prevents both over-ordering (expensive) and under-ordering (project-stopping).

Start with the rectangular portions. Each exterior wall is width × height. Walk the perimeter and measure each wall segment, including garage faces, bump-outs, and setbacks. Multiply each segment by its height and sum the results. Most estimators use the average wall height for simplicity — a 9-foot first floor and a 9-foot second floor with a 1-foot band board gives 19 feet of average wall height for a two-storey home.

Gable ends are triangles. The area of a gable is 1/2 × base × peak height. A 30-foot-wide gable with a 6/12 pitch has a peak height of 7.5 feet (30/2 × 6/12) and an area of 1/2 × 30 × 7.5 = 112.5 sq ft. Most homes have two gable ends. This area is often forgotten in estimates, leading to a shortage of 200+ sq ft of siding on a typical gable-roofed house.

Dormers add small wall sections on the roof. Each dormer has a face wall and two cheek walls. Measure each surface and add to the total. A typical dormer adds 30-60 sq ft of siding area.

Window and door openings reduce the siding area. Measure each opening (width × height) or use the standard deductions: interior doors = 21 sq ft, windows = 12-20 sq ft depending on size, sliding glass doors = 40-50 sq ft, garage doors = 128-160 sq ft. The total opening area on a typical home runs 15-20% of the gross wall area. If your openings exceed 20%, your house has a lot of glass — double-check the measurements because overestimating openings leads to under-ordering siding.

Installation Sequence and Common Failure Points

Siding installation follows a bottom-to-top sequence regardless of material type. Each course overlaps the one below, creating a shingle-like drainage plane that sheds water outward.

1. **Install housewrap and flash all penetrations.** The weather-resistive barrier goes on first. Flash window and door openings with self-adhesive flashing tape. The flashing sequence matters: sill first, then jamb sides, then head. This order ensures water flows over each lap rather than behind it.

2. **Install starter strip at the bottom of the wall.** The starter strip provides the angled surface that locks the first course of siding at the correct angle. Without it, the first course hangs flat against the wall and looks different from every course above.

3. **Install corner posts and J-channel.** These pieces frame the siding field. Corner posts go on before the siding so each course can butt into them. J-channel goes around windows, doors, and the soffit line to receive the cut ends of siding.

4. **Install siding courses from bottom to top.** Each course locks into the one below and nails at the top. Vinyl siding nails must not be driven tight — leave 1/32 inch between the nail head and the siding flange to allow thermal expansion. Fiber cement and wood are nailed tight because they do not expand as much. Stagger the end joints between courses by at least 24 inches (vinyl) or 16 inches (fiber cement) so that no two adjacent courses have joints in the same location.

5. **Final course and soffit trim.** The top course is cut to width, locked into the undersill trim, and capped. Soffit and fascia installation completes the exterior envelope. Soffit vents must provide adequate attic ventilation — typically 1 sq ft of net free area per 150 sq ft of attic floor area.

When Re-Siding Makes More Sense Than Repair

Patching damaged siding is cheaper than full replacement, but there are situations where the economics favour starting fresh. Understanding when to repair and when to replace saves money long-term.

Repair makes sense when the damage is localised — a few cracked planks, faded sections on one wall, impact damage from a fallen branch. Vinyl siding is the easiest to patch because individual courses can be unlocked, removed, and replaced without disturbing adjacent courses. The challenge is colour matching: vinyl fades with UV exposure, so new pieces never match old ones exactly. Replace the entire wall face rather than patching mid-wall to avoid visible colour differences.

Full re-siding is the better choice when the underlying housewrap or sheathing is compromised. If removing a damaged siding panel reveals rotted OSB, water-stained sheathing, or missing housewrap, the water problem extends beyond the siding itself. Re-siding the entire building lets you inspect and repair the sheathing, install fresh housewrap with proper flashing, and add exterior continuous insulation (R-5 to R-10 foam board) that dramatically improves energy performance.

The cost tipping point is roughly 30% — if more than 30% of the siding needs replacement, the labour savings of doing the full house at once typically outweigh the material savings of patching. A full re-side also provides a uniform appearance that patching cannot achieve, especially if the existing siding has faded or weathered unevenly over time. For the structural side of exterior wall projects, the [wall framing calculator](/calculators/structural/wall-framing-calculator) estimates studs and plates if any framing repairs are needed behind the siding.

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