Siding Repair & Replacement Calculator — Repair vs Replace
Enter your wall area and damaged area, pick your material, and get a patch cost range next to the cost of re-siding just the damaged zone — plus the 15% / 30% decision tree contractors use to call it.
Repair or Replace? Quick Decision Calculator
Net wall face after windows and doors. One typical wall is 200–400 sq ft.
Rough is fine — length × height of cracked, rotted, or hail-damaged zones.
Your Verdict
RepairHow the math works: patches = damaged sq ft ÷ 10, rounded up — one patch episode handles roughly a 10 sq ft zone. Patch rates: Vinyl $50–150, Cedar lap $75–200, Cedar shake $200–500, Hardie $100–300, Metal $60–180. Replacement uses the installed midpoint including tear-off: Vinyl $11/sq ft, Cedar lap $20, Cedar shake $25, Hardie $18.50, Metal $13.
Repair or Replace: The 15% / 30% Decision Tree
Every repair-versus-replace argument collapses into one number: what share of the wall is damaged? Under 15%, patching almost always wins because mobilization — showing up, setting ladders, matching the material — dominates the bill, and you pay it once. Above 30%, repeated patch episodes, fragile old material, and color drift push the piecemeal route past the cost of a clean re-side. The 15–30% band is the judgment zone. Here is the tree.
Under 15% of the wall is damaged → Repair
Emerald zone
Isolated damage on otherwise-healthy siding is the cheapest problem in the trade. One trip, one patch episode, done. Your calculator result at 6.7% damage (80 of 1,200 sq ft) shows why: roughly 8 patches at $400–$1,200 versus $880 to re-do the damaged strip — and the patch route keeps 93% of the wall untouched.
What tips it toward repair
- Siding is under 10 years old and the catalog color is still stocked.
- A new Hardie wall with one hail-cracked plank — textbook single-plank repair at $100–$300.
- Damage is mechanical (impact, one storm) rather than systemic (rot, moisture).
- Sheathing behind the damage probes solid with a screwdriver.
15–30% damaged → Evaluate before you commit
Amber zone
In this band the money alone doesn't decide it — three factors do. Price both paths, then weigh them against the age of the siding and whether a color-matched patch is even possible.
What tips it either way
- Age of siding: 20-year-old vinyl has gone brittle — it snaps during removal, so each “one-panel repair” breaks two more panels and the patch zone grows on its own.
- Color match availability: discontinued dye lots mean the patched wall shows a checkerboard even when the repair is structurally perfect.
- Hidden rot: open one suspect course; if the sheathing behind is soft, the damage is bigger than the visible footprint and the estimate doubles.
- Two or more walls damaged? Mobilization repeats per wall — replacement starts to win at roughly half the per-wall threshold.
Over 30% damaged → Replace the wall, not the pieces
Rose zone
Patch crews charge per trip and per matching headache; install crews charge per square foot and roll. Past 30% damage you are paying trip pricing on a third of the wall — the arithmetic flips permanently. Replace the full wall face once, with one waste factor and one color batch.
What confirms it
- Cracked, brittle 20-year-old vinyl snaps during removal — the repair consumes the salvage and the neighbors' panels too.
- Damage follows a moisture path (missing flashing, sprinkler spray) — patches will rot again in the same spots.
- Patch quote exceeds 60% of the full re-side quote for the same wall: stop, re-side.
- You already patched the same wall twice in three years — the third patch is the down payment on the re-side you postponed.
Contractors price repairs per patch episode, roughly one 10 sq ft zone per episode. Five cracked panels scattered across a wall can be five episodes — five mobilizations of setup, matching, and sealing — even though the total damaged area is tiny. Cluster your damage map before you call, because one episode covering five adjacent panels prices nothing like five distant ones.
What a Patch Costs, Material by Material
Patch pricing is not a scaled-down version of installation pricing — each material fails differently, comes apart differently, and punishes a careless remover differently. These five cards reflect how repair crews actually quote: per patch episode, per hour range, and per pitfall they know is waiting behind the damaged piece.
Vinyl Siding Repair
$50–$150 / patch
Time: 1–3 hrs · Skill: DIY-able
The friendliest repair in the trade. Vinyl unlocks: a $15 zip tool releases the interlock on the course above, the damaged panel slides out, a new one snaps home, and the course above re-locks over it. No sealant, no fasteners showing, no drying time — which is exactly why the contractor minimum feels steep for a ten-minute swap. You are mostly paying for the truck roll.
Watch for
- Dye-lot color drift: the same color name from a different production run sits visibly off-shade next to sun-faded panels.
- Cracking brittle neighbors: panels older than ~15 years lose flexibility, and prying near the damage snaps the adjacent lock legs.
Cedar Lap Siding Repair
$75–$200 / patch
Time: 2–4 hrs · Skill: DIY-able with care
Cedar lap comes off face-nailed, and that is the whole story of this repair. Each board is nailed twice into studs, so removal means either pulling nails through the face of the board above or splitting the board you came to save. New cedar is forgiving; weathered cedar splits along the grain the moment a nail head resists. Prime all six sides of the replacement board before it goes up.
Watch for
- Splitting face nails: backed-out nails lift the overlap above; pull them through the waste board instead of hammering them flat.
- Hidden sheathing rot: cedar hides moisture damage well — probe the wrap behind the lowest course before you close the wall up.
Cedar Shake Repair
$200–$500 / patch
Time: 3–5 hrs · Skill: Pro recommended
The most expensive common patch, and the one most often underestimated. Shakes are replaced as whole vertical columns — you cannot surgically remove one shake mid-column, because its neighbors overlap it on both sides and the courses above are woven through it. Extraction is where the cost lives: brittle old shakes shatter, and every shattered shake extends the column you must replace.
Watch for
- Breaking shakes during extraction: split old shakes with a hook blade and slide fragments out rather than prying the column whole.
- Woven courses: shakes interlace with felt or the courses above — restore the weave, or the patch channel water behind the wall.
Hardie Plank Repair
$100–$300 / plank
Time: 1–2 hrs · Skill: DIY with caution
Fiber cement repairs cleanly once the plank is out — the material is dimensionally stable and paintable, so a close color match is achievable with a quart of exterior latex. The cost driver is everything around the cut: silica dust control outdoors, the right diamond or polycrystalline blade, and the patience to unfasten blind nails without snapping the plank you intend to keep.
Watch for
- Dust control when cutting: fiber cement dust is silica-bearing — cut outdoors with a saw shroud and HEPA vacuum, never dry-saw over the porch.
- Blind-nail damage: nails hidden under the course above shear planks during removal — locate and back them out before flexing anything.
Metal Panel Repair
$60–$180 / panel
Time: 1–2 hrs · Skill: DIY-able
Steel and aluminum panels are mechanical swaps: unsnap the fasteners, slide the damaged panel up and out, nest the new one in and refasten. Physically it is the easiest large-panel repair in the trade. The hard part is visual, not structural — paint technology has changed enough that a ten-year-old panel and a fresh one from the same color family can disagree loudly in afternoon sun.
Watch for
- Color fade matching after 10+ years: order the replacement from the original finish code if it exists, and expect a two-shade difference on south-facing walls.
- Oil-canning on refastening: overdriven or over-tight screws pin the panel and ripple the flat — fasten snug, not crushed.
Patch work: removal, match, sealPhoto: UnsplashCaulking a warped shake or a bowed vinyl panel seals in whatever warped it. If a board moved, moisture or fastener failure moved it — find the cause, fix the substrate, then patch. A $6 tube of caulk over a $2,000 sheathing problem is the most expensive shortcut in exterior repair.
A Worked Repair Example: 8 Cedar Shakes
Numbers beat adjectives, so here is a complete patch quote built line by line — the kind of math a shake-repair crew runs in their head before they quote you $700 and it sounds arbitrary.
The patch: 8 shakes, 3 columns
The alternative: re-side the wall
The damaged share is 24 ÷ 288 = 8.3% — comfortably inside the emerald zone. The $720 patch is exactly 10% of the $7,200 full re-side, and that ratio is the whole argument: at low damage percentages, patch labor priced per square foot of affected area beats install labor priced per square foot of total wall. The crossover, in this cedar-shake example, lands somewhere above 30% — which is precisely why the decision tree draws the line there.
Color Matching: The Hardest Part of Any Patch
Structurally, most siding repairs are simple. Visually, they are brutal, because color never stays put on an exterior wall. UV light, manufacturing lots, and finish chemistry all drift — and a patch that is perfect in every mechanical sense can still be the most visible thing on the house.
Vinyl: the dye-lot problem
Vinyl is pigmented in production batches, and every batch drifts slightly — same color name on the label, marginally different shade on the wall. Stack five years of UV fading on top and a brand-new “identical” panel reads like a repair from across the street. This is dye-lot drift, and no amount of installer skill removes it.
Hardie: match the official name
Hardie ColorPlus plank is matchable by official color name — the finish is baked in the factory, so the same name is the same color across production runs. For discontinued codes, cross-reference the stamped code on the back of an existing plank; distributors can map old codes to the current palette, and unpainted primed plank can be topcoated to close any residual gap.
Harvest donors before buying
Before you order anything, walk the house looking for hidden donor pieces: behind shrubs, behind the AC unit, on the north wall, inside the garage gable nobody sees. A weathered panel pulled from behind the hydrangeas will match your visible wall far better than a fresh carton — and the fresh carton then patches the hidden spot where nobody compares shades.
Cedar: silver in 2–3 years
Cedar weathers to silver within 2–3 years of UV exposure, so any new patch stays brighter than the wall around it for at least two seasons. Your options: stain or prime the whole wall face later so everything converges, or patch the least-visible wall first, let it weather, and use it as the donor bank for the street-facing walls.
New patch, old wall — the shade gapPhoto: UnsplashCalculating a Partial Clapboard Re-Side
Sometimes the damage bands horizontally — rotted bottom courses, splash-back from a grade problem, snow-thrower scars. That is a partial re-side, and the question becomes: how do I calculate how much clapboard siding I need for just the damaged courses?
Partial re-side formula
Area = Damaged courses × Exposure × Wall length, then + 10% wasteConvert area to lineal feet: lf = Area × 12 ÷ exposure-inches. Boards needed = lf ÷ board length, rounded up.
Worked example: 3 rotted courses on a 40 ft wall
The same logic scales up. For a whole home shingle siding replacement, you stop thinking in courses and start thinking in squares: total wall area minus openings, plus a 15–18% waste factor for woven shingle courses, priced at full installed rates. That is the territory of a full re-side calculator flow rather than a patch quote — and we maintain two tools for exactly that step up in scope. The takeoff & waste calculator turns your wall measurements into an order quantity with the right waste factor per profile, and the cost calculator matrix prices the full re-side across every material side by side, so you can compare the partial-repair number you just computed against the whole-wall number before you commit either way.
Rot concentrated in the bottom 1–2 courses is usually a moisture problem (grade contact, missing starter flashing, sprinkler overspray), not a siding problem. Pull one course and probe the sheathing and sill plate before ordering your 11 boards — if the substrate is soft, the correct order is carpentry first, clapboard second, or the new courses will rot on the same schedule as the old ones.
DIY vs Pro Repair Costs
The DIY discount on siding repair is real but uneven — it is largest where the material is forgiving (vinyl) and smallest where specialty tools or extraction skill dominate (shake, fiber cement). Here is the honest side-by-side.
| Material | DIY materials cost | Pro patch cost | Skill |
|---|---|---|---|
| Vinyl | $20–$60 (zip tool ~$15) | $50–$150 | DIY-able |
| Cedar lap | $80–$150 | $75–$200 | DIY-able with care |
| Cedar shake | $80–$150 materials | $200–$500 | Pro recommended |
| Hardie plank | $60–$120 (fiber cement blade, dust mask) | $100–$300 | DIY with caution |
| Metal panel | $30–$90 | $60–$180 | DIY-able |
Neutral note on ladder safety: most DIY repair injuries come from the access, not the siding. Set extension ladders on level footing at the correct lean angle, keep your hips between the rails, and never stretch sideways past the rail to reach one more course.
DIY ladder falls are the real cost driver in home siding repair — a single two-story patch saves perhaps $100 in labor but puts you on an extension ladder handling a pry bar, a nail puller, and a brittle panel at the same time. Two-story patches are usually pro territory: the crew has staging, standoffs, and the repetition to move fast at height. Ground-level repairs are where the DIY discount is actually safe to collect.
Where to Go From a Patch Quote
Whether you arrived searching for a siding repair calculator to price one damaged corner or comparing vinyl siding repair cost against a full re-side, the rest of the decision lives in the tools on this site. The main siding calculator handles full-wall material takeoffs and installed-cost estimates for every profile, the all siding calculators hub covers coverage, gables, takeoff waste, and material-specific math, and the siding guides library walks through installation, maintenance, and buying decisions in plain language. Price the patch here, price the wall there, and let the 15% / 30% tree make the call.
Frequently Asked Repair & Replacement Questions
How much does it cost to repair vinyl siding?▼
A single vinyl siding patch typically costs $50–$150 per patch from a contractor, with most repairs finished in 1–3 hours. The price covers unlocking the panel with a zip tool, swapping the damaged piece, and re-locking the course. DIY material cost is only $20–$60 because a zip tool costs about $15 and individual panels are cheap — the contractor price is mostly labor and trip charge.
Is it cheaper to repair or replace siding?▼
Repair is almost always cheaper when damage stays under 15% of the wall. Example: 80 sq ft of damaged vinyl on a 1,200 sq ft wall is 6.7% damage — roughly 8 patches at $400–$1,200 total, versus about $880 to replace just the damaged area tear-off included, or $13,200 to re-side the whole wall. Between 15% and 30% damage the numbers converge and age plus color-match availability should drive the call. Above 30% damage, replacement usually wins because patch labor scales worse than full-wall install labor.
How much does cedar shake repair cost?▼
Cedar shake repair runs $200–$500 per patch because shakes must be replaced as whole vertical columns — you cannot patch one shake mid-column without breaking its neighbors during extraction. Shakes are installed with a woven interlock, so each removal disturbs the courses above and below. A worked example: replacing 8 shakes across 3 columns in a 12-inch exposure wall affects 24 sq ft and totals roughly $720 ($600 labor at $25/sq ft plus $120 material at $5/sq ft).
How do I calculate how much clapboard siding I need for a repair?▼
For a partial re-side, multiply the number of damaged courses by their exposure, then by the wall length. Worked example: the bottom 3 courses of 6-inch clapboard rot on a 40 ft wall: 3 × 0.5 ft = 1.5 ft tall × 40 ft = 60 sq ft. Add 10% waste for 66 sq ft. Convert to lineal feet at 6-inch exposure: 66 × 12 ÷ 6 = 132 lf. With 12 ft boards, order 132 ÷ 12 = 11 boards.
Can you match old vinyl siding color?▼
Sometimes, but expect dye-lot drift. Vinyl made in a different production run carries the same color name yet can sit slightly off-shade, and after 5+ years of UV exposure the installed panels have faded further from the current catalog color. Best practice is to harvest donor pieces from hidden spots — behind shrubs, behind the AC unit, or on the north wall — before buying new. If the patch must be visible, plan to re-side the least-visible wall first and use it as the donor source.
How much does a Hardie plank repair cost?▼
Hardie plank repair costs $100–$300 per plank professionally, with DIY materials at $60–$120 including a fiber-cement blade and dust mask. The higher contractor price versus vinyl reflects the tools involved: fiber cement must be cut with dust control, and blind-nailed planks can crack if extraction is rushed. A single hail-cracked plank on a newer Hardie wall is a textbook repair — not a re-side.
What percentage of damage means full replacement?▼
A common working threshold is 30%: when more than 30% of a wall's area is damaged, replacement of the whole wall usually costs less per square foot than piecemeal patches, because patch labor includes repeated mobilization, matching, and careful extraction that full install crews avoid. Under 15% damage, repair is the optimal strategy in most cases; the 15–30% band is an evaluate zone where siding age, color-match availability, and hidden rot decide it.
Related Siding Calculators
Hardie & Fiber Cement
Coverage, cost, and board count for James Hardie 7.25″/8.25″...
Vinyl Siding
Vinyl Double 4, 4.5, 5 coverage tables, shake siding, board-...
Wood Siding
Cedar lap, clapboard, shake, and shingle coverage, board foo...
Metal Siding
Corrugated, ribbed, standing seam, steel lap, and aluminum s...
Board & Batten
Board width and batten spacing tables, center exposure formu...
Garage & Shed Siding
Garage and shed siding takeoff: 5 standard size presets, gar...
Linear Feet Converter
Convert siding square footage to linear feet and board feet ...
Siding Cost
Siding cost calculator for 6 materials: vinyl, fiber cement,...
Takeoff & Waste
8-step siding takeoff with waste factors by material, nail c...
Coverage & Exposure
Coverage for all 10 siding profiles: D3–D6 vinyl, lap 4–8 in...