A customer calls: "my siding is all wavy." Before you price anything, figure out why. Wavy vinyl usually comes down to one of three things, and the fix is different for each.
1. It was nailed too tight
Vinyl moves. It grows in the heat and shrinks in the cold, and it needs room to slide. If the installer drove the nails tight to the wall or nailed through the face instead of the center of the slots, the panel can't move. In summer, it buckles.
How to tell: The waves are worst on sunny walls in warm weather. Try sliding a panel side to side. If it won't move at all, it's pinned. Look for nails driven hard against the hem.
The fix: Pull the panels and rehang them correctly: nails centered in the slots, with a little space under the head so the panel can slide. Often the panels themselves are fine once they're rehung.
2. Heat from outside
Reflected sun from a neighbor's low-E windows, a grill too close, or a dark-colored panel on a hot wall can warp vinyl.
How to tell: The damage is in one area, sometimes in a pattern. Look for melting or a sheen. See grill-melted siding repair.
The fix: Replace the damaged panels and tell the customer about the cause. If it's reflected sunlight, the new panels can warp again. Window screens or plants are sometimes enough to block it.
3. The wall behind it
Siding is only as flat as what's under it. Bowed studs, swollen sheathing from a leak, or furring that was never straightened will all show through.
How to tell: The waves don't change with the weather. Press on the panel. Is it soft or spongy behind? Pull a panel and look.
The fix: That's no longer a siding repair. Water damage, rot or framing problems need to be priced separately. Be clear on the estimate about what you're fixing and what you're not. See siding repairs to walk away from.
Price after you know
Never quote wavy siding on the phone. The fix could be an hour of rehanging or a wall of rot. Go look first.
Inside Siding Pro Academy, members post their wavy-siding photos and the group helps figure out which cause it is.
