How to Repair Aluminum Siding in Less Than an Hour

These common techniques are crucial for any homeowner with aluminum siding. You'll learn how to make a small patch and fill in a dent.

exterior, home, lawn, garden
Photo: Kritsada
Project Overview
  • Total Time: 1 hour
  • Skill Level: Kid-friendly

Most aluminum siding joins together like vinyl, which means that in order to make a repair, you'll need to patch a damaged area or replace a panel. This tutorial shows you both techniques.

Be aware that metal corner caps are sometimes used instead of corner posts for aluminum siding, and in older installations, they were often used for wood or hardboard lap siding as well. If your local supplier does not have caps to match the ones on your house, check online sources; it helps if you know the manufacturer's name. In a pinch you can cut and shape a piece of sheet metal to fit, using an old cap as a template.

Also, know that aluminum siding can and should be painted. Scrape any flaking paint, and sand smooth. Pressure-wash and allow to dry. Apply an alcohol-based primer or an oil-based primer that has been thinned with 2 cups of thinner per gallon of primer. Apply acrylic paint.

Most repairs will take less than an hour, and you'll only need simple cutting and measuring skills. Before you begin, check the siding closely for further damage to determine how large a section of siding needs to be replaced.

What You'll Need

Equipment / Tools

  • Hammer
  • Tape measure
  • Pliers
  • Putty knife
  • Nail set
  • Lineman's pliers
  • Taping blades
  • Flat pry bar
  • Tin snips
  • Hacksaw
  • Sanding block
  • Scraper
  • Caulking gun
  • Ladder


  • Butyl caulk
  • Replacement end caps
  • Auto-body filler
  • Sandpaper


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    Cut Out Damaged Area

    Tap with a hammer to indent the damaged area or use tin snips or a utility knife to cut it out.

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    Cut Patch

    Cut a patch 4 inches longer than the damage and cut off the nailing flange. Test the fit; the patch should just slip under the siding above.

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    Apply Caulk

    Apply beads of butyl caulk on each side of the patch area and around the hole. Press the patch into place. Use duct tape to hold it in place while the caulk dries.

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    Pull Out Screw

    If a dent is deep, partially drive a coarse-threaded screw into the center and pull it partway out with a pair of pliers. If part of the damaged area protrudes, tap with a hammer to indent it slightly.

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    Apply Auto-Body Filler

    Scrape and sand away any loose paint. Clean with a mild detergent solution, rinse and allow to dry thoroughly. Mix a batch of auto-body filler and apply it over the indentation, using the plastic scraper that comes with the filler.

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    Scrape and Paint

    When it gets hard but not dry, generally shape the filler with a scraper. When it dries use a hand sander to smooth the patch. Prime and paint.

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