Why Has the New Vinyl Siding on My New House Buckled?

The Hanging Factor

• The most likely cause of buckling siding is a result of the installer driving the nails tightly against the house boxing. Vinyl siding expands and contracts with temperature changes, and it will not withstand being nailed snugly to the house. The siding literally “hangs” on nails that extend about 1/16 inch from the wall surface. The top lip of a row of siding features a nailing flange with pre-cut spaces for the nails. When installed accurately, you should be able to wiggle the siding back and forth slightly.

Pressure on the Trim

• The second cause for buckled vinyl siding is due to the ends of the siding strips pressing on the adjacent trim. J-mold, the trim that goes around doors and windows, and corner mold are installed before the flat siding pieces. When the installer measures a row of siding, he should cut it 1/4 inch short of the actual measurement to allow for expansion. It the strips press tightly against the trim, when the siding expands, it’s likely to buckle.

Seam Issues

• A standard strip of siding is long, usually around 16 feet in length, and both ends feature factory cutbacks on the lip of the nailing flange. The installer will start at one side of the wall and work toward the other side. When he has to cut a strip of siding to fit at the far end, he will cut off a section to start the new row. In this way, the siding seams will always have a cutback on the flange for easy fitting. If the installer uses small strips, with both factory ends cut off, he must cut back the flange by hand or the seams will fit together tightly, restricting free movement when the siding expands and causing the affected row to buckle.

Solutions

• If you catch the problem as soon as it occurs, the installer can remove the siding and rehang it, piece by piece, taking care not to nail it too tightly or allow it to press against the trim. If you wait a few months, however, the siding may be permanently warped. Rarely, buckling may be due to a factory error, so keep a copy of the manufacturer’s warranty. Most warranties are void, however, if the siding was not installed to the manufacturer’s specifications.