The most common cause of buckled or warped vinyl siding is an installation that does not allow the siding to expand and contract separately from the wall below it with changes in temperature. Vinyl siding has a higher coefficient of expansion than the wood surface on which it is typically mounted. 

    So it should not be securely nailed in place like other siding, but “hung” from nails at the center of long slots along the top of each siding section, with a gap between the head of each nail and the surface of the vinyl about the thickness of a dime. This allows the siding to move independently from the wall below it as the temperature changes.

    A thinner, less epensive grade of vinyl siding is also more prone to deformation. The vinyl siding shown in the photo at the top of the page was a lower grade of vinyl, on a wall with a southern exposure, nailed tightly to the siding.

    Unfortunately, sometimes homeowners fix the problem by face nailing the warped areas, which only makes the problem worse.

    Other causes warped siding include:

•• Placing a portable barbecue too close to a vinyl-sided wall. This usually creates an small, oval area of deformation.

•• Reflected heat from an adjacent home with high-efficiency windows with a reflective film.

•• Movement of the underlying wall due to settlement or termites.

   Once vinyl loses it rigidity, it cannot be repaired and the problem area must be replaced.

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Here’s links to a collection of some of our other blog posts about VINYL SIDING:

• Can vinyl siding be painted?   

• How can I tell if vinyl siding is installed correctly?

• What do you look for when inspecting vinyl siding?

• Can vinyl lap siding be installed diagonally? 

• What are the pros and cons of vinyl siding?

• What is the average life expectancy of vinyl siding? 

    Visit our SIDING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles. 

Diagrams - Vinyl Siding Institute and InterNACHI