How to Repair Vinyl Siding

Understanding the Parts of Vinyl Siding & Replacing Them at Home

New home showing vinyl siding and gutters
ghornephoto / Getty Images
Project Overview
  • Working Time: 45 mins - 1 hr, 30 mins
  • Total Time: 45 mins - 1 hr, 30 mins
  • Yield: 1 patch
  • Skill Level: Beginner
  • Estimated Cost: $10 to $50

Although it is a highly versatile and water-resistant siding material, vinyl plank siding can also be somewhat fragile under some conditions. It can melt in intense heat or become brittle in cold weather. When cold, it is especially prone to impact damage—a small stone thrown by a snowblower can easily crack vinyl siding. Vinyl siding is more resilient in the heat of summer, but a sharply hit baseball from kids playing in the driveway can still damage it.

Repairing small sections of vinyl siding can be expensive if you have a repair person come out for a house call. A contractor can charge $300 or more for a simple vinyl siding repair. But you can repair vinyl siding yourself for a small fraction of the price. If you have a spare section of matching siding already available, this repair can cost you almost nothing.

Before You Begin

To match perfectly, a vinyl siding repair must use a piece with the same design and style as the surrounding siding. This is no problem if you've had the foresight to save leftover pieces from the last time your home was sided. Many homeowners will tuck away leftover pieces on a shelf or the garage rafters. Even if you were not the owner when the house was last sided, you might find that the previous owner saved some pieces.

The repair job becomes more complicated if you don't have any leftover pieces lying around. Manufacturers usually discontinue patterns and styles every few years, making it difficult to find a match. If you have an older vinyl siding installation, take a sample of what you have on the home to a nearby siding supply company for a match. In some cases, supply companies catering to professionals will still have some stock for your siding.

The repair demonstrated here shows how to cut out a section of damaged vinyl siding and replace it with a patch that spans the damaged area. But another option, if you happen to have a leftover full-length panel, is to side your house with a new piece of vinyl siding by removing and replacing the entire panel. The advantage is that the repair will have the same seam pattern as the original installation.

Tip

What if you can't find matching siding? An interesting service that can analyze your vinyl siding and find you a match is ITEL Siding Matching Service. For a fee, they will analyze your vinyl siding and provide you with a complete siding description and distributor location so you can purchase your replacement vinyl siding. They can even help you if your vinyl siding design has been discontinued.

Parts and Components of Vinyl Siding

Vinyl siding includes several parts and accessories to fasten the siding to a house. The main features of vinyl siding include:

  • Backer board
  • Starter strip
  • Buttlock
  • Flange
  • J-channel
  • F-channel
  • Flashing
  • Fascia
  • Furring strip
  • Inside corner post
  • Outside corner post
  • Lock and locking leg
  • Soffit

Vinyl siding consists of thin, molded planks of solid vinyl plastic with layers of backer board underneath. The pieces are designed to move as outside temperatures rise and fall, and the system relies on being interlocked at the top and bottom to achieve its weather tightness. Understanding the technique used in the interlocking process is the key to successfully replacing a damaged piece.

Vinyl siding trim pieces are called J- and F-channels, which include small holes for the siding panels to lock into. Other standard pieces include the starter strip, soffit trim, and fascia trim, which are visible on the home's exterior.

The siding is fastened to the house with nails driven through elongated holes in the nail hem at the top of the planks. However, it is critical that the nails not be driven tight against the nail hem, or the siding will lose its ability to move, which may cause buckling. This is the most common error made in vinyl siding installation. Therefore, as you install the new piece, you need to ensure a 1/32-inch gap between the nail head and the vinyl siding (about the thickness of a dime).

To attach or separate vinyl siding requires a special siding removal tool called a zip tool that is used to join or unlock the interlocking flanges at the bottom of each plank.

Vinyl siding profile diagram
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What You'll Need

Equipment / Tools

Replace a Section of Siding

  • Vinyl siding zip tool
  • Tin snips
  • Pry bar
  • Claw hammer
  • Utility knife
  • Framing square

Fix a Hole or Dent

  • Putty knife
  • Paint brush

Materials

Replace a Section of Siding

  • 1 section of matching vinyl siding
  • Galvanized siding nails

Fix a Hole or Dent

  • 100-grit sandpaper
  • 220-grit sandpaper
  • Sandable exterior filler or putty
  • Exterior paint
  • Shop rag

Instructions

How to Replace a Section of Vinyl Siding

  1. Unlock the Vinyl Siding Plank

    • To access and remove the damaged section of vinyl siding, you must first unlock the siding above and below the damaged area.
    • Using a zip tool, unlock the vinyl siding above the damaged section by inserting the curved tip of the tool blade under the end of the overlapping panel and hooking onto the back lip of the section's bottom edge (buttlock).
    • Then, pull the tool downward while sliding the tool away from the end, which will separate the panel across its length.
    • Repeat for the bottom edge of the damaged panel.
  2. Remove Nails Above the Damaged Area

    The damaged vinyl siding panel will now hang free since you have disconnected it at the top and bottom.

    Tip

    Remove the nails holding the panel directly above the damaged area using a pry bar. This will make it easy to cut out the damaged section of the siding.

  3. Cut Out the Damaged Section

    Cut out the damaged section of siding using a pair of tin snips. Use care not to cut the top or bottom edges of the panels above or below the area you are removing.

  4. Cut a Replacement Section

    • Using a framing square as a cutting guide, cut a replacement section from a piece of leftover siding long enough to overlap the removed area by about 1 1/2 inches on each side. Use a utility knife with a new, sharp blade to cut the piece, running it alongside the edge of a framing square held tight against the siding piece.
    • Now, trim back the nail hem by about 2 inches on each side of the replacement section so it fits into the space of the removed section.
  5. Install the Replacement Section

    • Slide the replacement section into position. Hook the replacement section's buttlock into the lock at the top edge (top lock) of the piece below. Push the replacement up until it snaps into place.
    • Driving galvanized siding nails through the nailing hem to resecure the panel, spaced about 12 inches apart and centered in the elongated holes. Leaving a 1/32-inch gap between the nail head and the siding.
    • The nails must be long enough to penetrate at least 3/4 inch into the framing or furring.
  6. Relock the Panel

    • With the patched panel nailed in place, use the zip tool to relock the top and bottom edge in place. This is done in the same way you used to unlock the panel:
    • Insert the curved tip of the tool blade under the end of the overlapping panel and hook it onto the back lip of the section's bottom edge (buttlock).
    • Pull the tool downward while sliding away from the end, which will join the panel across its length.

How to Fix Dents or Holes in Vinyl Siding

If your vinyl siding has a small hole, dent, or crack, fill it and paint over it. You’ll need matching exterior paint so the repair blends in unnoticeably.

  1. Smooth Out the Work Area

    Using the 100-grit sandpaper, sand the problem area, smoothing it out to give you a clean, more easily workable surface.

  2. Apply Putty or Filler to the Problem Area

    • Apply filler or putty to the hole, crack, or dent using a putty knife. Scrape away any excess filler.
    • Smooth the repair area with the putty knife.
    • Let the area dry.
  3. Sand the Area to Smooth It Out

    • Sand the dried filler using 220-grit paper.
    • Wipe it clean with a damp rag.
    • Let it dry.
  4. Paint Over the Repaired Section

    Get a matching exterior paint and paint over the repair to help it blend in with the rest of the siding.

When to Call a Professional

When deciding whether to call a professional, the number one issue to determine is how big the project is. Call the professionals if a large section of the siding needs replacing, not just a panel or a section of a panel.

Remember, the savings might be negligible if you also need to buy new tools and supplies to fix the problem. Sometimes the peace of mind of an expert fix is worth a few extra dollars. Also, siding professionals usually offer warranties on their work, so they will make sure it gets done right the first time.

Tip

You might save yourself in labor costs, but not necessarily if it takes you many hours or days versus an expert who can do it quickly.

Another consideration is where the section needs repair. If it's in a tough spot to work, such as up high on the house or a corner, the eaves, soffits, fascia, or along the trimming openings like windows and doors, a professional repair is the better option.

If, upon inspecting the area that needs repair, you notice mold, water, or pest damage on your home, call an expert to get at the root cause of the problem before covering up the issue. Also, if you need permits to work on the siding of your home, a professional siding expert will know if you need to go through the formal process and can handle it for you.

How Often to Replace Vinyl Siding

Vinyl siding has become popular over wood and aluminum because of its durability and low maintenance. It can last up to 60 years but may have a shorter lifespan depending on weathering, sun exposure, and other environmental factors. Fading is the biggest issue that can occur within 20 to 30 years, depending on if you get a specific color that makes it noticeable.

Vinyl siding rarely needs repair unless significant storm damage or a freak accident occurs. It can warp and get cracks, loose panels, or holes, but it's not common. If the siding was installed professionally with high-quality materials, it should last the test of time.

FAQ
  • What are common mistakes when installing vinyl siding?

    Vinyl siding can not be nailed too tightly to the home, as it needs movement during weather changes. Other common mistakes include:

    • Leaving excess overlap between siding panels
    • Installing fasteners too far apart
    • Using the wrong backer board
    • Leaving visible seams between panels
  • What holds vinyl siding in place?

    Siding panels attach with built-in locks attached to each side of the panel. Different types of vinyl siding pieces (J- and F-channels) are needed for each corner of the home and center spaces where the two panels meet. Panels are attached to the home via nails through the fastening holes on the flange.

  • Should the bottom of siding be sealed?

    The bottom of vinyl siding should not be sealed. If you notice a gap here, it's installed correctly: The siding is open on the bottom for drainage purposes to prevent water damage and allow water to escape.