Roof-Master 221 Plus Ultimate Rubberized Flashing Cement

Product Fast Facts
Ultimate Rubberized Cement
Remains Flexible
Extra Durable


Roof-Master Plus 221 Ultimate Rubberized Flashing Cement is a high grade SBS rubberized flashing cement manufactured using the highest quality chemical ingredients. Roof-Master Plus 221 Ultimate Rubberized Flashing Cement is soft, pliable cement that gradually hardens to a compound that is elastic, durable and resistant to water.

Real Results


Specially formulated for use in damp, wet roofing situations. Roof Master Plus 221 Ultimate Rubberized Flashing Cement can be used as a heavy duty flashing cement for repairing flashings, asphalt shingles, built-up roofs, metal and masonry surfaces. Great for sealing leaks and openings at flashings (chimneys, vents, skylights, metal joints, gutters). DO NOT USE with EPDM, PVC, TPO or other single-ply membranes.


Surface must be clean and free of dirt, dust, oil or grease and be free of any other foreign matter that would interfere with good adhesion. In colder climates we recommend storing the product at room temperature for 24 hours prior to application.


Apply with a trowel or putty knife. Spread Roof Master Plus 221 to approximately 1/8” thickness and work thoroughly into the problem area. Repairing cracks and blisters: if the area is 1/4” wide to 2” long apply United Asphalt Cotton or Fiberglass Fabric for reinforcement, then cover with additional cement.


Approximately 8 gallons per 100 sq. ft. (per coat)

Cleanup Roof-Master+ Ultimate Rubberized Flashing Cement

Clean tools with Del-Val Orange Cleaner & Degreaser or mineral spirits, taking necessary precautions when handling combustible liquids.

Code Approvals/Compliance

This product meets or exceeds the requirements of ASTM 4586 Type I and ASTM D-3409.

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