221 Wet/Dry Roof Cement

221 Wet/Dry Roof Cement

221 Wet/Dry Roof Cement

A versatile, professional-grade performer, Mule-Hide #221 Wet/Dry Roof Cement is an all-weather, asphalt-based flashing cement ideally suited to repairing leaks in many types of asphaltic roofing membranes. It can be applied to wet or dry surfaces. Its heavy, trowel-grade consistency makes it ideal for sealing and patching temporary emergency holes and cracks in roofs, even in standing water.

  • Can be used to repair conventional built-up roofs, asphalt shingles, metal roofs, and masonry surfaces.
  • Seals leaks and openings around all types of flashings, including chimneys, vents, skylights, metal joints, gutters, and similar components of built-up flashings.

  • ModBit
  • M&R

Features & Benefits

  • Great bonding strength. An interlocking fiber matrix ensures uniform and excellent adhesion
  • Heavy trowel-grade consistency
  • Highly flexible to accommodate the temperature-related expansion and contraction of the roofing system
  • Readily adheres to wet and dry surfaces.
  • Displaces standing water from wet surfaces in emergencies, creating a tight seal
  • Exceptional durability and performance over a wide range of challenging temperatures and weather conditions. Will not mud crack and will remain highly resilient and durable through all seasons.
  • Excellent sag resistance when used on vertical surfaces, even at high temperatures
  • Does not damage conventional asphalt-based roofing membranes
  • Easy to use. Ready to apply right out of the container. Smooth texture for hassle-free application using a pointed trowel, wide-edged putty knife, or gloved hand.
  • Meets  Miami-Dade-County Standards



Item ID Description Packaging Qty per Ctn Weight per Ctn Cover Rate
16MH2213 MH 221 WET/DRY ROOF CEMENT 3 GAL Metal Pail 1 32 8 gallons per 100 sq. ft. for 1/8"
16MH2215 MH 221 WET/DRY ROOF CEMENT 5 GAL Metal Pail 1 51 8 gallons per 100 sq. ft. for 1/8"


Application Example Image


The coverage rate for Mule-Hide #221 Wet/Dry Roof Cement is approximately 8 gallons per 100 sq. ft. for a 1/8-inch (3 mm) coat applied to both surfaces. (All values are approximate and may vary with ambient temperature and job conditions.)
Mule-Hide #221 Wet/Dry Roof Cement can be applied using a pointed trowel, a wide-edged putty knife, or a gloved hand.
No. Mule-Hide #221 Wet/Dry Roof Cement is NOT RECOMMENDED for use with modified bitumen (APP, SBS) roofing membranes.
No. DO NOT USE Mule-Hide #221 Wet/Dry Roof Cement with PVC, TPO, EPDM or other single-ply roofing membranes.
With proper storage, the shelf life of Mule-Hide #221 Wet/Dry Roof Cement is 24 months from the date of manufacture.
Mule-Hide #221 Wet/Dry Roof Cement should be stored at a temperature of at least 45°F but not above 120°F. It should be stored at room temperature for at least 24 hours prior to application.
Mule-Hide #221 Wet/Dry Roof Cement should only be applied when the ambient temperature is at least 45°F and rising. Cold weather can result in uneven application and improper curing, and it will cause the product to stiffen, making application more difficult. Application is not recommended if the substrate temperature is above 140°F.

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