Assess Your Rust Damage First
Before deciding on repair or replacement, assess the severity of your garage door rust. Regular maintenance can prevent rust from forming in the first place - see our complete maintenance guide for prevention tips.
Surface Rust / Discoloration
Orange-brown discoloration, slightly rough texture, paint bubbling. Metal underneath is intact.
Flaking Rust / Pitting
Rust flakes off when touched, visible pitting in metal surface, affects 10-30% of door.
Penetrating Rust / Holes
Rust has eaten through metal, visible holes, structural weakness, affects 30%+ of door.
What Causes Garage Door Rust
Understanding the causes helps prevent future rust problems. In Toronto and the GTA, these are the main culprits:
Road Salt Spray
Vehicles tracking road salt into the garage creates a corrosive environment. Salt spray reaches the lower panels directly. This is the #1 cause in Toronto winters.
Paint Damage
Scratches, chips, or dings from impacts expose bare metal. Even small scratches can start rust that spreads under surrounding paint.
Standing Water
Water pooling at the bottom of panels (often from snow melting off cars) stays in contact with metal for extended periods, accelerating oxidation.
High Humidity
Garages without proper ventilation trap moisture from vehicles, especially in spring when warm air meets cold surfaces. Condensation forms on metal.
DIY Rust Removal: Step-by-Step Guide
For mild to moderate surface rust, follow these steps for a lasting repair:
Supplies Needed:
Clean the Entire Door
Wash with mild dish soap and water using a soft brush. Remove all dirt, grease, and road salt. Let dry completely (at least 2-4 hours in good weather).
Remove Loose Rust & Paint
Use a wire brush or wire wheel attachment on a drill to remove all flaking rust and loose paint. Work until you reach stable material. Finish with 80-grit sandpaper.
Apply Rust Converter
Apply rust converter (like Rust-Oleum Rust Reformer) to all rust spots. This chemically converts remaining rust into a stable black compound that won't spread. Let dry 24 hours.
Sand Smooth
Once the converter has cured, sand with 120-grit then 220-grit sandpaper. Feather the edges where old paint meets bare metal for a smooth transition.
Apply Rust-Inhibiting Primer
Apply a quality rust-inhibiting primer (Rust-Oleum, Tremclad, or Zinsser) to all bare metal areas. Extend slightly onto surrounding paint. Apply 2 thin coats, drying between.
Paint with Exterior-Grade Paint
Apply 2-3 thin coats of exterior acrylic latex or oil-based paint. Let each coat dry per manufacturer instructions. For best results, paint the entire door for uniform appearance.
💡 Pro Tip: Best Weather for Rust Repair
Paint and rust converter work best when applied at 10-30°C (50-86°F) with low humidity. In Toronto, the ideal windows are:
- Best: Late May through September
- Acceptable: Late April or October (watch for rain)
- Avoid: Winter months - paint won't cure properly
Repair Costs: DIY vs Professional
Here's what to expect for different repair approaches in the Toronto area:
| Repair Type | Cost Range | What's Included | Best For |
|---|---|---|---|
| DIY Rust Treatment | $50 - $150 | Supplies: sandpaper, converter, primer, paint | Surface rust, handy homeowners |
| Professional Rust Treatment | $200 - $400 | Prep, conversion, prime, paint (spot repair) | Moderate rust, time-constrained |
| Full Door Repaint | $350 - $600 | Complete door prep and repaint | Multiple rust spots, color change |
| Single Panel Replacement | $150 - $400 | New panel, paint match, installation | One panel with holes |
| Full Door Replacement | $800 - $2,500+ | New insulated steel door, installation | Multiple panels rusted through |
When to Replace vs Repair
Use this decision guide to determine the most cost-effective approach:
✓ Repair Your Door If:
- Rust is surface-level only (no holes)
- Affects less than 30% of door surface
- Door is less than 15 years old
- Panels are not warped or dented
- Repair cost is under 50% of replacement
⚠️ Replace Your Door If:
Rust has eaten through metal creating holes, multiple panels affected, structural integrity is compromised (door sags or binds), or total repair costs exceed 50% of new door price. Also consider replacement if the door lacks modern safety features.
Rust Prevention: Keep Your Door Protected
Prevent rust from returning with these maintenance practices:
Seasonal Rust Prevention Checklist
Additional Prevention Tips
- Fix paint chips immediately - Use touch-up paint within days of noticing damage
- Improve garage ventilation - Install vents to reduce humidity buildup
- Park with hot side out - Let snow/ice melt outside before pulling in
- Apply rust inhibitor spray - Products like WD-40 Specialist or Fluid Film protect exposed areas
- Check weatherstripping - Replace worn seals that let moisture in
- Consider rust-resistant upgrades - Aluminum or fiberglass doors don't rust at all
Frequently Asked Questions
Yes, surface rust on garage doors can usually be repaired through sanding, rust conversion, and repainting. However, if rust has penetrated through the metal creating holes, or if more than 30% of the door is affected, panel replacement or full door replacement is typically more cost-effective.
DIY rust repair costs $50-$150 for supplies. Professional rust treatment and repainting costs $200-$500 in Toronto. Replacing a single rusted panel costs $150-$400. Full door replacement due to extensive rust damage ranges from $800-$2,500+ depending on door type and size.
Garage door rust is caused by: road salt spray from vehicles (major cause in Toronto winters), scratched or chipped paint exposing bare metal, standing water at the bottom of panels, high humidity inside the garage, and age-related paint failure. Steel doors without galvanization are most susceptible.
Prevent rust by: washing the door seasonally (especially in spring to remove winter salt), touching up paint chips immediately, applying automotive wax twice yearly, ensuring proper drainage away from the door, and maintaining weatherstripping to reduce moisture exposure.
Repair if: rust is surface-level only, affects less than 30% of door, no holes have formed, and door is less than 15 years old. Replace if: rust has eaten through metal, multiple panels affected, structural integrity compromised, or repair costs exceed 50% of replacement cost.
Not Sure If Your Door Can Be Saved?
Our Toronto technicians can assess your rust damage and recommend the most cost-effective solution. Free estimates on all repairs. Book online.
📞 437-265-9995