Physical Impact Damage
Physical damage results from impacts like hail, baseballs, fallen branches, lawn equipment, and other direct contact. The damage pattern typically reveals the cause: round dents suggest hail, irregular holes suggest impact debris, and linear damage at ground level often points to lawn mower contact.
Vinyl Siding Impact Damage
Vinyl cracks rather than dents. Hail creates circular fractures. Other impacts cause irregular holes or splits. Cracked vinyl siding doesn't repair; the damaged sections must be replaced. Individual panel replacement costs $100-300 including labor when matching panels are available.
The main concern with vinyl impact damage is water entry. Small cracks may allow moisture behind the siding, where it can damage sheathing or cause mold growth. Inspect any cracked vinyl for evidence of water penetration.
Wood Siding Impact Damage
Wood dents and splinters from impacts. Small dents can be filled and painted. Larger damage may require board replacement. Wood repair is more forgiving than vinyl because damaged areas can be patched and blended.
Fiber Cement Impact Damage
Fiber cement (like HardiePlank) chips and cracks on impact. It's more brittle than wood but more durable than vinyl. Chips at the bottom edge of panels are common from lawn equipment contact. Small chips can be patched; larger damage requires panel replacement.
Aluminum Siding Impact Damage
Aluminum dents but rarely punctures. Hail creates dimpled patterns across large areas. Dented aluminum siding remains functional but looks damaged. Individual panels can be replaced, though matching old aluminum can be difficult.
Moisture and Rot Damage
Moisture damage is the most serious category because it indicates ongoing water intrusion that can spread to underlying structures. The Insurance Institute for Business & Home Safety estimates that water damage accounts for over 20% of homeowner insurance claims, with many originating from exterior cladding failures.
Wood Rot
Rot occurs when wood remains wet long enough for decay fungi to establish. Signs include soft spots that probe easily, discoloration (gray, brown, or black areas), paint failure, and visible fungal growth. Rot most commonly appears at:
- Bottom edges of siding near ground contact
- Around window and door trim
- Beneath gutters with drainage problems
- At horizontal surfaces where water pools
Rot repair requires cutting out all affected wood plus a margin of sound wood, then replacing with new material. Costs range from $200-500 for small areas to $2,000+ for extensive rot.
Mold and Mildew
Mold appears as black, green, or gray patches on siding surfaces. It thrives in shaded, humid locations. Surface mold on vinyl or painted surfaces often cleans off with appropriate solutions. Mold growing under or behind siding indicates moisture problems requiring investigation.
Water Staining
Staining patterns below windows, at wall transitions, or beneath roof edges indicate water pathways. The staining itself is cosmetic, but it reveals where water is running. Follow the stain upward to find the source: failed caulking, missing flashing, gutter problems, or siding installation defects.
Efflorescence
White mineral deposits on masonry and stucco indicate water moving through the material and evaporating on the surface. Occasional efflorescence after heavy rains is normal. Persistent or heavy deposits suggest ongoing moisture intrusion.
UV and Weather Degradation
Sun exposure degrades all siding materials over time. South-facing and west-facing walls age faster than protected exposures. UV degradation is inevitable but can be slowed by proper maintenance.
Vinyl Fading and Chalking
Vinyl siding fades and develops a chalky surface over 15-25 years. The chalking is degraded surface material. Fading is cosmetic but indicates the siding is aging. Once chalking becomes significant, the vinyl is becoming brittle and more prone to cracking.
Paint Failure on Wood
Paint on wood siding fails progressively: first chalking, then cracking, then peeling, then bare wood exposed. Each stage allows more moisture into the wood. Bare wood exposed to weather deteriorates within 1-2 years without protection.
Repainting every 7-10 years prevents paint failure from reaching the peeling stage. Once peeling occurs, preparation requires scraping and priming bare wood before painting.
Fiber Cement Color Fading
Factory-painted fiber cement typically maintains color well for 15-20 years. Site-painted fiber cement follows the same degradation pattern as painted wood. Faded fiber cement is purely cosmetic; the material itself remains sound.
Stucco Surface Deterioration
Stucco develops hairline cracks from normal building movement and temperature cycling. These hairline cracks are maintenance items requiring elastomeric coating. Larger cracks, bulging, or hollow areas indicate more serious problems with the underlying structure or moisture intrusion.
Installation Defects
Some siding problems stem from improper installation rather than age or damage. These defects may be present from day one but become apparent over time.
Vinyl Buckling and Warping
Vinyl expands and contracts significantly with temperature changes. Installers must leave room for this movement. When panels are nailed too tightly or too far from center, they buckle, warp, or crack when temperature changes force expansion against the constraint.
Buckled vinyl is usually cosmetic but indicates the siding will fail prematurely. The fix requires removing and reinstalling panels with proper techniques.
Missing or Improper Flashing
Flashing directs water away from vulnerable transitions: above windows, at roof-wall intersections, and where siding meets dissimilar materials. Missing or improperly lapped flashing allows water behind the siding.
Flashing problems often don't show visible symptoms until significant damage has occurred. Inspectors look for proper flashing installation at all transitions.
Inadequate Clearance to Ground
All siding materials require clearance above ground level (typically 6-8 inches minimum). Ground contact holds moisture against the siding and invites pest entry. Siding installed too close to grade often shows accelerated deterioration at the bottom edge.
Missing Housewrap or Drainage Plane
Modern construction requires a weather-resistant barrier behind siding. Older homes and poorly done renovations sometimes lack this protection. When siding fails, water reaches the sheathing immediately with no secondary protection. This defect only becomes apparent when the siding is removed.
Pest Damage
Various pests damage siding directly or by tunneling behind it.
Woodpecker Damage
Woodpeckers create round holes in wood siding, typically 1-2 inches in diameter. They're looking for insects in the wood or creating nest cavities. Woodpecker activity often indicates insect infestation in the wood. The holes themselves need repair, but the underlying cause requires investigation.
Carpenter Bee Damage
Carpenter bees bore perfectly round half-inch holes in unpainted wood, then tunnel along the grain. Evidence includes the holes plus sawdust below. Carpenter bee damage accumulates over years as multiple generations expand tunnel networks.
Termite and Carpenter Ant Damage
Wood-destroying insects rarely attack siding directly but may enter through ground contact or follow moisture pathways. Visible damage to siding suggests a larger infestation requiring professional inspection.
Damage Severity Assessment
Not all siding damage requires immediate action. Severity depends on whether the damage is cosmetic, allows water intrusion, or indicates underlying structural issues.
Cosmetic Only
Faded vinyl, minor dents in aluminum, surface mold that cleans off, and small chips at ground level are cosmetic issues. They affect appearance but not function. Address at your convenience or when selling the home.
Maintenance Required
Peeling paint, failing caulk, cracked panels, and deteriorating sealants need attention before they progress. These items allow water entry if not addressed. Most can wait months, not years.
Urgent Attention
Active rot, large areas of missing siding, water staining inside the home, and visible moisture damage require prompt repair. Delay allows the damage to spread and increases repair costs.
Repair Cost Ranges by Material
Repair costs vary significantly by material, extent of damage, and regional labor rates.
Vinyl Siding Repairs
Individual panel replacement: $100-300 per panel including labor. Larger sections: $5-8 per square foot installed. Finding matching panels for older vinyl can be challenging and may require replacing entire wall sections for consistent appearance.
Wood Siding Repairs
Small rot repairs: $200-500. Board replacement: $10-20 per linear foot plus painting. Full wall restoration with extensive rot: $2,000-5,000. Wood siding repairs are labor intensive because of preparation and painting requirements.
Fiber Cement Repairs
Panel replacement: $300-600 per panel installed. Fiber cement is heavier and more brittle than other materials, making replacement labor intensive. Matching paint colors on older installations can be difficult.
Stucco Repairs
Crack repair: $8-50 per linear foot. Patch repair: $200-500 per patch. Matching stucco texture and color requires skilled work. Large repairs may require recoating entire wall sections for consistent appearance.