Overlapping vinyl siding panels correctly is essential for a professional appearance and long-term performance. The primary goal is to ensure seams are properly covered while allowing the siding panels to expand and contract freely with temperature changes.
A key technique in achieving proper overlap, as highlighted in Kaycan Vinyl Siding installation guidance (like the video referenced from 0:36-1:52), is not fully locking the panel where the overlap occurs. This allows for necessary movement.
Key Principles of Overlapping Vinyl Siding
Vinyl siding expands and contracts significantly with temperature fluctuations. Incorrect overlapping is a major cause of buckling and waving siding.
- Standard Overlap: Typically, siding panels are overlapped by about 1 inch (2.5 cm). This amount is usually marked on the siding panel itself.
- Allow for Movement: This is the critical point emphasized by manufacturers like Kaycan. When butting two panels together for an overlap, the end of one panel should not be fully locked tightly into the end of the previous panel. As the reference notes, ensure the panel is "not fully locked in the panel".
- Consistency: Maintain the same overlap amount and the same degree of loose locking ("It have the same") at every overlap joint. This ensures a uniform appearance and consistent allowance for movement.
Why Not Fully Lock at the Overlap?
Vinyl siding panels are designed to move. If you nail or lock them tightly at the overlap joint (and at other points), this movement is restricted.
- Expansion: When temperatures rise, the vinyl expands. If locked tightly, it has nowhere to go but outward, causing the siding to buckle or wave unsightly.
- Contraction: When temperatures fall, the vinyl contracts. If locked tightly when installed cold, it can pull apart at the seams or strain the fasteners.
By not fully locking the panels together at the overlap, you create a small space or flexibility that allows the panel ends to slide slightly as they expand or contract, preventing stress and distortion.
Achieving a Proper Vinyl Siding Overlap
Follow these steps for effective overlapping:
- Determine Overlap Amount: Identify the standard overlap mark on your specific siding product (usually 1 inch).
- Position the Second Panel: Bring the second panel up to overlap the first panel by the required amount.
- Do Not Fully Lock: Where the tongue and groove ends meet for the overlap, connect them loosely. Do not push them together until they are tightly engaged or fully locked. Leave a small amount of play.
- Maintain Consistency: Ensure this loose connection and the 1-inch overlap are consistent at every joint.
- Nail Properly: Fasten the panels using the nailing hem, but again, do not drive nails tightly. Leave about 1/32 inch (0.8 mm) of space between the nail head and the siding to allow the panel to slide back and forth on the nail shank.
- Stagger Overlaps: Avoid lining up overlap joints vertically between rows. Stagger them to distribute the seams and enhance the wall's appearance and structural integrity.
By following the principle of "not fully locked in the panel" at the overlap and ensuring consistent application, you help prevent buckling and achieve a professional, long-lasting vinyl siding installation.
