The best waterproof sealant for shingles depends on the application, but for general shingle repair and sealing, asphalt-based roofing cement is the industry standard and recommended by shingle manufacturers. Products like Henry 208, Black Jack, or Geocel 2300 are widely used by professional roofers. Asphalt roofing cement is a thick, sticky, black mastic that remains flexible, adheres well to asphalt shingles, and is compatible with the shingle's chemistry, unlike silicone which does not adhere well. It is ideal for sealing lifted tabs, sealing around flashing, covering exposed nail heads, and sealing small punctures. For sealing shingle tabs that have lost their factory seal, a quarter-sized dab of roofing cement under each tab provides excellent wind resistance. For ridge caps and flashing, polyurethane sealants like Geocel 2300 or OSI Quad are excellent because they remain flexible, are paintable, and adhere to multiple materials. For small nail holes or minor cracks, clear roofing sealant in a caulk tube can be used. Never use silicone caulk as primary shingle sealant, as it does not bond well to asphalt and can prevent proper sealing. Also avoid using excessive tar or non-asphalt products that can damage shingles. Always apply sealant on a dry, clean surface in moderate temperatures for best adhesion and use sparingly, as too much can interfere with water shedding.
1 votes
Marked as accepted