Unlike wood clapboards, vinyl siding is so thin and flexible that each piece has to lock onto the ones above and below to keep a house weatherproof. So when a piece of vinyl breaks, the “key” to making the repair is a zip tool, a miniature curved pry bar with a metal hook at its tip to unlock the siding. Here’s how to use it.
1. Snap out the old piece. Wedge the zip tool up into the horizontal joint where the “hook” at the bottom edge of the damaged piece fits into the “lock” of the piece below. Pull the tool down and out as you work it along the joint until the hook pops free. Do the same along the joint above the damage. Now, using a pry bar, remove the nails from the damaged piece.
Why It Locks: Vinyl siding is so thin and flexible that each piece has to lock onto the ones above and below to keep a house weatherproof. So when a piece breaks, the “key” to making the repair is a zip tool — a miniature curved pry bar with a metal hook at its tip designed specifically to unlock the siding.
2. Snap the new piece on. Cut a replacement piece to length with a sharp utility knife guided by a square. It should be at least 2 inches longer than the space it is covering. Hold the piece horizontally so that each end overlaps the neighboring siding by at least one inch. Hook the replacement’s bottom edge into the lock at the top edge of the piece below. Push the replacement up, under the piece above.
Finishing the Job: If you can’t pull the siding above down far enough to lock into the replacement piece by hand, use a zip tool — its small hook catches the bottom edge of the upper piece so you can pull it down and away just enough to snap it into place over the new piece’s nailing strip.
Pro Tip: Tom Silva, This Old House general contractor, emphasizes the importance of keeping your siding intact: “Siding is a raincoat for your house. If you’ve got a hole in the raincoat, you’ve got problems.”
3. Nail it. Lift the overhanging piece out of the way, then nail the new piece in place with 1¼ to 1½-inch aluminum siding nails. Drive a nail every 16 inches, aiming for the center of the prepunched holes along the nailing flange at the top. The nails shouldn’t pinch the siding; vinyl needs to expand and contract.
Pro Tip: Tom Silva, This Old House general contractor, advises that when nailing siding before zipping it into place, you should never nail it tight to the wall: “I don’t want the nail to be tight because the siding needs to expand and contract or slide on that nail.” A too-tight nail will prevent movement and cause the siding to ripple.
4. Zip it. Hook your zip tool onto the lock at the top of the replacement siding and pull it slightly outward and down. At the same time, push the lower edge of the existing siding in toward the house with your free hand until it engages the replacement piece’s groove, as demonstrated above. Slide the zip tool horizontally until all the siding above snaps into the lock’s groove.
How It Works: Each piece of vinyl siding is molded to look like two courses of siding. On the top of each piece is a nailing strip with holes or slots for attaching the siding to the wall. Below the nailing strip is a small channel — when you install a new piece of siding, the bottom of the new piece snaps into that channel. When you need to remove or replace a piece, you push down on it and it pops out.
TOH Tip: Because of all the bending required, the best time to repair damaged vinyl siding is in summer, when the plastic is warmer and more flexible.
Where to Find It
Vinyl siding removal tool: SRT1
Malco Products Inc.
Annandale, MN
800-596-3494
