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Siding · Usually workmanship

Buckling or waviness in vinyl

Usually installation: vinyl must be hung loosely so it can expand. Nailed tight, it buckles in summer heat. That is a workmanship issue rather than a product failure.

Quick answerVinyl siding grows and shrinks noticeably with temperature. It’s designed to hang on its nails, free to slide side to side. When it’s nailed tight, nailed outside the center of the slots, or butted hard against trim, it has nowhere to go on a hot day, so it bows out. That’s a workmanship problem, not a bad product. The fix is to unlock the affected panels and re-fasten them correctly.

Wavy vinyl is often blamed on cheap siding. Usually the panels are fine and the nailing is wrong. That matters, because the fix and who pays for it depend on which it is.

White horizontal lap siding on a house wall, seen from below against a clear blue sky
Courses should run straight and even. Waves that come and go with the heat point to panels that can’t move. Photo by Sebastian Schuster on Unsplash.

1Why vinyl buckles

  • Nailed too tight. Nail heads driven hard against the panel pin it in place.
  • Nails off-center. Nails at the ends of the slots leave no room to move one way.
  • No expansion gap. Panels jammed into corner posts and J-channel can’t grow.
  • Uneven wall. Bumps in the sheathing behind show through as waves.
  • Heat. A grill or other heat source too close can distort vinyl permanently.

2How to check what you’re dealing with

  1. Compare morning and afternoonWaves that appear in the heat and relax in the cool point to tight nailing.
  2. Try to slide a panelIn a mild spot, a properly hung panel should shift slightly side to side. One that won’t budge is pinned.
  3. Check the endsLook where panels meet corner posts and trim. They should not be jammed hard into the channel.
  4. Look for meltingDistortion near a grill or vent is heat damage, not installation.

3Fixing it

Do it yourself

  • Note when and where it buckles and take photos
  • Move grills and heat sources away from the wall
  • On a small single-story area, unlock the panel and back the nails out slightly

Hire a pro

  • Call the original installer first; it’s their workmanship
  • Re-fasten panels loosely, centered in the slots
  • Trim panel ends to leave expansion room
  • Replace panels that have permanently distorted

Check your installer’s workmanship warranty before paying anyone else. Product warranties often exclude damage from improper installation, so get the installer’s answer in writing.

4What drives the cost

How many walls are affected, whether panels can be re-hung or have permanently distorted, wall height, and whether matching panels are available. If the original installer is still in business, the cost may be theirs.

Siding cost

Vinyl waving across whole walls?

Talk to a siding contractor who can re-hang it correctly.

877-360-4657

5Questions

Will buckled vinyl flatten out on its own?

It may relax when it cools, but the waves come back every hot day until the panels are re-fastened.

Is this covered by the siding warranty?

Usually not, if the cause is installation. Ask the installer about their workmanship warranty.

Do I need new siding?

Not usually. Most buckled panels can be re-hung. Only permanently distorted panels need replacing.

Written by Jaylan Jones. I Like To Exterior Services earns a referral fee when a call connects to a contractor. See our business-model disclosure.

877-360-4657