When using asphalt shingles from different lot numbers, what potential problem may arise?

Choosing asphalt shingles from different lot numbers can lead to color blending issues. This is because asphalt shingles are manufactured in batches, and slight variations can occur in color, texture, or finish. When shingles from different lots are installed side by side, even subtle discrepancies may become noticeable once the roof is installed and exposed to sunlight, rain, and other environmental factors. This can result in an uneven appearance that detracts from the aesthetic value of the roof.

While it might seem that these variations could impact performance, which would relate to options like loosening of shingles or decreased roof lifespan, the primary concern is most closely associated with the visual uniformity. Structural instability isn't a typical consequence of using shingles from different lots, as long as the shingles themselves meet the necessary building standards and are properly installed. Therefore, the key issue with using shingles from different lots primarily centers around maintaining consistent color and appearance across the roof.