If the dimension of a chimney parallel to the ridgeline exceeds 30 inches, what feature must be provided?

When the dimension of a chimney parallel to the ridgeline exceeds 30 inches, a cricket must be provided to ensure proper water drainage and prevent the accumulation of snow and ice. The purpose of a cricket, which is essentially a small roof structure placed on the uphill side of the chimney, is to divert water away from the chimney and reduce the risk of leaks or water damage to the roof and chimney itself. By directing water flow, a cricket helps maintain the integrity of the roofing system and enhances the overall efficiency of the chimney's installation. This is especially critical in areas where heavy precipitation is common, as it significantly mitigates potential water-related issues. Understanding this feature's role is crucial for both effective installation and long-term maintenance of roofing systems involving chimneys.