Aluminum Siding Repair: A Guide To Restoring Your Home's Exterior

Aluminum siding was a popular choice for homes in the 1940s to the 1970s. However, it has its drawbacks, including being susceptible to dents, scratches, and holes. Repairing aluminum siding can be a challenging task, but it is possible to do it yourself without the need for professional help. In this guide, we will walk you through the process of repairing common issues with aluminum siding, such as holes, dents, and scratches, and provide you with the tools and techniques needed to tackle these issues.

Patching holes

Aluminum siding may be less popular now than in its heyday, but it can still look nice and last a long time if properly maintained. Patching holes in aluminum siding is a straightforward job that doesn't require specialized tools. Here are the steps to repair a hole in aluminum siding:

Smooth Out the Damaged Area

The first step is to flatten or remove any jagged edges of the hole. Grab a hammer and gently tap the pointed edges until they point inward (toward the house). Alternatively, you can use tin snips or a utility knife to cut away the rough edges of the hole.

Prepare the Area

If there is any paint or corrosion around the hole, sandpaper or scrape it off the edges and the area surrounding the hole. Then, clean the area with soapy water and rinse thoroughly to remove any soap and debris. Dry the area with an absorbent paper towel.

Get Siding for Your Patchwork

You'll need a replacement piece of aluminum siding to use as your patch. If you have leftover siding from the original installation, grab a piece to begin cutting. Otherwise, purchase a matching replacement piece. If an exact match is not available, you can settle for something close or use a piece from a less visible area of your house.

The patch siding should be longer than the hole in the damaged panel. Cut the panel to size, leaving about 4 inches on either side of the hole. After cutting, use tin snips to remove the nailing flange on the replacement siding.

Apply Caulk or Filler

Apply butyl caulk around the hole in the existing siding. Then, apply caulk or filler in vertical lines about 3 inches out from each side of the hole. You can use plastic aluminum, auto-body filler, or a two-part epoxy filler for this step. If using a two-part epoxy filler, be sure to carefully follow the mixing instructions.

Install the Patch

Slide the patch under the siding above the damaged panel and press it into place. Use duct tape to hold the patch in place while the caulk or filler dries.

Sand and Paint

Once the filler or caulk is dry, gently sand it down to match the surrounding aluminum area. Then, apply a coat of primer and paint to match the rest of the siding. Be sure to use an exterior paint or enamel suitable for metal.

Fixing dents

Aluminium siding is prone to dents and dings, but the good news is that these are usually easy to repair without the need for professional help. Here's a step-by-step guide to repairing dents in aluminium siding:

Step 1: Drill a Hole

Drill a small hole (approximately 1/8 of an inch) into the centre of the dent. This hole should only go through the aluminium and not the house underneath. The purpose of this hole is to provide an anchor for pulling out the dent and for back-filling later.

Step 2: Insert a Screw

Select a sheet metal or self-tapping screw that is slightly wider than the hole you've drilled. Place a washer on the screw—this will help avoid damaging the surrounding siding as you work. Insert the screw into the hole and turn it a few times until it has a firm grip on the siding without affecting the house material underneath.

Step 3: Pull Out the Dent

Using your fingers or a pair of pliers, gently tug on the washer to pull out the dent. Be cautious if you are standing on a ladder and avoid using too much force. In most cases, it shouldn't take a lot of force to pull out the dent.

Step 4: Apply Filler

Once the dent has been removed or reduced, use sandpaper to remove any remaining paint from the area. Then, fill the dent with an auto-body filler or putty. Use a putty knife to scrape the surface, levelling it with the siding. Allow the filler to dry.

Step 5: Sand and Paint

Once the filler is dry, use a fine-grit sanding sponge or sandpaper to smooth the patched area. Be careful not to scratch the surrounding siding. If necessary, apply more filler and sand again until the patch is smooth. Finally, prime and paint the repaired area to match the rest of your siding.

Repairing scratches

If the scratch is on a section of siding that is easily removable, you may want to take it off and lay it on a flat surface to make the process easier.

If the scratch is deep, you may need to fill it with auto-body filler before painting.

Removing and replacing panels

Before removing any panels, it is important to identify the type of aluminum siding on your house. The most common type is horizontal lap siding, which comes in two designs: shiplap and dutch lap. To identify which type you have, hold a flat object like a level or straight board firmly against the siding. If a lot of light passes through, you probably have shiplap siding. If very little light passes through, it is likely dutch lap.

If you are still unsure, remove a piece of siding that is large enough to show the profile and take it with you to a supplier. They will be able to identify it.

Aluminum siding is delicate and should be handled carefully. It is prone to denting and crimping, and can be permanently damaged by bird strikes, stones from lawnmowers, hail, or any other type of severe impact.

The fastest and easiest way to repair damaged siding is to remove and replace the panel(s). This is because the siding usually has a wood grain texture, which is extremely difficult to replicate with fillers.

Step 1: Detach the Locking Tab From the Damaged Panels

Use a siding removal tool to detach the locking tab from the damaged panels. This tool has a thin, curved blade designed to slide behind a siding panel and disengage the locking tab. This method avoids applying greater force on the surrounding panels, reducing the risk of accidental damage.

Step 2: Remove the Fasteners From the Locking Tab

After detaching the locking tab, gently raise the panel to insert a flat bar. A flat bar is typically a short (12"-18") flat pry bar with a hook on one end and a sharp edge on the other. Slide the flat bar behind the panel, between the locking tab and the wall, and apply gentle pressure to loosen the fasteners.

Most installers used roofing tacks, which are easy to remove. However, some installers used ring shank or twist nails, which are designed to resist removal. If you encounter such a fastener, you can either drive it into the wall or cut it away, and then apply house wrap tape over it to seal the hole.

Step 3: Replace the Siding

Horizontal lap siding is installed from the bottom up, like a shingle. Lock the new piece of siding by snapping it onto the locking tab of the course below. Then, apply gentle pressure to lift and nail the new piece in place using a galvanized roofing tack or another weather-resistant fastener.

Do not drive the fasteners in tightly, as this will cause the piece to buckle when exposed to intense heat or cold. Most manufacturers require an ⅛" gap between the head of the fastener and the siding.

If you need to overlap two pieces horizontally, overlap them by 6"-8" to allow the siding to shed water more easily and create a more pleasant appearance by offsetting the vertical joints.

Remember, there is usually a distinct left and right side to aluminum siding. To reduce mistakes and material waste, cut from the same end every time.

Tools

• Siding Removal Tool
• Handheld Crimp Tool
• Flat Bar
• Galvanized Roofing Tacks or Other Weather-Resistant Fasteners

Painting

Clean the Siding

Firstly, you need to clean the siding thoroughly. You can use a power washer, a pressure washer, or even clean by hand with a scrub brush and a mild cleaning solution. If using a power washer, ensure it has a pressure between 1,700 psi and 2,800 psi. Always work from the top down to avoid forcing water behind the siding. If there is any old paint that is peeling or chipping, remove it with a paint scraper and sand down the edges with 100-grit sandpaper.

Choose the Right Paint and Primer

The best type of paint to use on aluminium siding is water-based acrylic latex paint. This type of paint is flexible and can resist cracking as the metal expands and contracts. Choose a premium product to ensure a long-lasting finish. You may also need a primer, especially if the siding has any bare metal patches or is in poor condition. Oil-based primers are best for aluminium but are more difficult to work with than water-based primers.

Prepare the Area

Cover any areas that you don't want to be painted, such as windows, doors, and outlets, with painter's tape and masking film. Lay down drop cloths to protect the pavement and any plants or foliage.

Apply Primer and Paint

You can apply the primer and paint with a brush, roller, or sprayer. Always work in the direction of the siding when using a brush or roller. If using a sprayer, mask off any areas you don't want to be painted and work in small sections. Allow the primer to dry for at least an hour, then apply the first coat of paint. You can apply a second coat if necessary, after the first coat has dried.

Safety Considerations

Remember to always wear the appropriate safety gear when working with chemicals and paint. This includes gloves, goggles, waterproof boots, and ear protection. If using TSP or other household cleaning products, check if your state bans these products due to their phosphate content.

Frequently asked questions