For vinyl siding, what is the recommended overlap to accommodate thermal expansion?

For vinyl siding, what is the recommended overlap to accommodate thermal expansion?

• A. 1/2 inch
• B. 1 inch
• C. 1-1/4 inch
• D. 1-1/2 inch

Answer: (B)

Vinyl siding changes size with temperature. When it heats up, it expands; when it cools, it contracts. To keep the joints tight and prevent buckling or gaps, installers leave an opening that the panels can slide into as they move. About one inch of overlap is the standard amount that provides enough room for this expansion and contraction across typical temperature ranges, while still keeping the seam covered and the weather barrier intact. If the overlap is smaller, movement is restricted and buckling or gaps can occur. Larger overlaps aren’t necessary for normal conditions and can disrupt the siding profile.

Vinyl siding changes size with temperature. When it heats up, it expands; when it cools, it contracts. To keep the joints tight and prevent buckling or gaps, installers leave an opening that the panels can slide into as they move. About one inch of overlap is the standard amount that provides enough room for this expansion and contraction across typical temperature ranges, while still keeping the seam covered and the weather barrier intact. If the overlap is smaller, movement is restricted and buckling or gaps can occur. Larger overlaps aren’t necessary for normal conditions and can disrupt the siding profile.