How to Repair Vinyl Siding

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.

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.