Repairing Vinyl Siding

New home showing vinyl siding and gutters
ghornephoto / Getty Images

Introduction to Repairing Vinyl Siding

Vinyl siding is the most fragile of all siding materials and can melt in intense heat or become brittle in cold weather. When cold, vinyl is especially prone to impact damage such as cracking or breaking apart. Repairing small sections of vinyl siding can be an expensive proposition if you have a repair technician come out for a house call. A contractor can charge $300 or more for the vinyl siding repair.

You're going to learn how to make the vinyl siding repair for a small fraction of that price. If you have a spare section of siding still available and don't have to buy it, this moderately difficult repair will cost you less than $10.

Needed Tools and Materials

Obtain Replacement Vinyl Siding Stock

Various styles of vinyl siding
Diane Labombarbe/Getty Images

Getting replacement vinyl siding that matches your existing siding will either be the easiest or most difficult part of the repair. Besides coming in textures and colors not found in nature (like some of the above), vinyl siding patterns and colors can be discontinued which makes it difficult to match.

If you have vinyl siding left over from the original installation, then it's easy to get the replacement stock.

If you have an older vinyl siding installation, then you need to take a sample of what you have on the home to a nearby contractor siding supply for a match.

What if you can't find a match? An interesting service that can analyze your vinyl siding and find you a match is called ITEL Siding Matching Service. For a fee, they will analyze your vinyl siding and provide you 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 is discontinued.

How Vinyl Siding Goes Together

Vinyl siding profile diagram

Vinyl siding is thin, flexible, moves with variations in outside temperature and relies on being interlocked at the top and bottom to achieve its weather tightness. As you will soon see, it is the technique used in the interlocking process that is the trick to removing and installing the siding.

It is fastened to the house with nails driven through elongated holes in the nail hem. However, it is CRITICAL that the nails not be driven tight against the nail hem or else the siding cannot move with temperature changes and will buckle. This is the most common error made in vinyl siding installation.

You need to make sure there is a 1/32" gap between the nail head and the vinyl siding (about the thickness of a dime).

To attach or to separate vinyl siding requires a special siding removal tool called a zip tool. Let's review how to use this tool in the next section.

Zip Tool - Unlocking the Vinyl Siding

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 hook onto the back lip of the buttlock.
  • Then pulling the tool downward while sliding the tool away from the end continue separating the panel all the way across its length.
  • Learn how to use a zip tool.
  • Repeat for the bottom edge of the damaged panel.

Remove Nails Directly Above Damaged Area

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

  • Remove the nails holding the strip directly above the damaged area.
  • Remove the nails by using a pry bar.

Cut Out Damaged Section of Vinyl Siding

Next, you will have to cut out the damaged section of vinyl siding.

  • 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.

Cut and Install Replacement Vinyl Siding

Next, you will cut and install a section of replacement vinyl siding for the repair.

  • To make speedy work of cutting the siding, use a quality layout square like the Stanley Quick® Square that will give you a clean, straight right angle cut when cutting the replacement section of vinyl siding.
  • Cut the siding using a utility knife with a new blade.
  • Cut the replacement piece of vinyl siding about 3" longer than the section you removed. This gives you about 1½" of overlap on both ends.
  • You must also cut back the nail hem about 2" on each side of the replacement panel, so it fits into the space of the removed section.
  • Slide the replacement section into position. Hook the replacement section's bottom edge ( buttlock) into the lock at the top edge (top lock) of the piece below. Push the replacement up until it snaps into place.
  • Space the nails about 12" apart and center them in the elongated holes in the nail hem.
  • Leaving a 1/32" gap between the nail head and the siding, nail the replacement panel into place using galvanized nails with heads a minimum of 5/16" in diameter and with a shank of 1/8" in diameter.
  • The nails must be long enough so they can penetrate at least 3/4" into framing or furring.

Relock Top Edge of New Vinyl Siding Section

Once you have the new patch installed, you need to use the zip tool to relock the top edge of the vinyl siding.