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 an extremely 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 an expensive proposition if you have a repair person come out for a house call. A contractor can charge $300 or more for a rather simple vinyl siding repair. But you can make vinyl siding repair 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

In order to match perfectly, a vinyl siding repair must use a piece of siding that is the same design and style as the surrounding siding. This is no problem at all 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 on the garage rafters. Even if you were not the owner when the house was last sided, you may well find that the previous owner saved some pieces.

But the repair job becomes more complicated if you don't have any leftover pieces laying around. Manufacturers usually discontinue patterns and styles every few years, which can make 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 here is that the repair will have the same seam pattern as the original installation.


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 different parts and accessories used to fasten the siding to a house. The main parts 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 common pieces include the starter strip, soffit trim, and fascia trim, which make up the visible trim 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, you need to make sure there is a 1/32 inch gap between the nail head and the vinyl siding (about the thickness of a dime) as you install the new piece.

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

What You'll Need

Equipment / Tools

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


  • 1 Section of matching vinyl siding
  • 1 Galvanized siding nails


How to Repair 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 section.

    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 all the way across its length.

    Repeat for the bottom edge of the damaged panel.

  2. Remove Nails Above the Damaged Area

    The damaged panel of vinyl siding will now be hanging free since you have disconnected it at the top and bottom. Using a pry bar, remove the nails holding the panel directly above the damaged area. This will make it easy to cut out the damaged section of siding.

  3. Cut Out the Damaged Section

    Using a pair of tin snips, cut out the damaged section of siding. Use care not to cut the top or bottom edges of the panels above or below the section 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 along side 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 so they can penetrate at least 3/4 inch into 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 exactly 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 the tool away from the end, which will join the panel all the way across its length.

  • What are common mistakes when installing vinyl siding?

    Vinyl siding can not be nailed too tightly to the home, as it needs to have movement during weather changes. Other common mistakes include leaving excess overlap between siding panels, installing fasteners too far apart, using the wrong backer board, or leaving visible seams between panels.

  • What holds vinyl siding in place?

    Siding panels attach to each other 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 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: Siding is open on the bottom for drainage purposes to prevent water damage and allow water to escape.