SeamStitch Polyurethane Caulk


SeamStitch Polyurethane Caulk is a silver, solvent-based brush grade polyurethane caulk.


Seals sheet metal fasteners, seams, laps and flashings prior to the application of elastomeric roof coatings.


  • Maintenance coating provides a seamless, durable membrane to seal and repair existing leaky roofs.
  • Breathable membrane prevents moisture entrapment and premature roof failure.
  • Superior adhesion to difficult to adhere substrates makes this an excellent primer and base coat asphalt and single ply roofs.
  • Top coat with silicone roof coatings to enhance UV and ponding water resistance.


  • Mix thoroughly before using. Thinning not recommended.
  • Roof must be clean, dry and free of any oil, grease, dirt or loosely adhered coating. Bare surfaces must be prepared and checked for compatibility. 
  • Always perform an adhesion test before coating the entire roof.
  • Clean up with Xylene.
  • Equipment: putty knife, bulk loader.
  • Refer to our Application Specifications and Safety Data Sheets. For professional use only.
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Warning: This product contains solvents. Keep away from open flame, heat or sparks. Pumping equipment should be grounded to avoid accidental ignition due to static sparks. Use only in ventilated areas and provide mechanical ventilation in enclosed spaces. Avoid breathing vapor or mist. Approved (MESA/NIOSH) chemical respirator and protective clothing must be used when exposure can exceed recommended PEL. Fresh air hose masks required for interior applications. Care must be taken to prevent rooftop HVAC from introducing solvent vapor into interior areas. Lexis Coatings must be completely dry before exposing to water or foot traffic. Keep Lexis Coatings containers covered when not in use. Dispose of all containers in accordance with state and local environmental regulations. Keep away from children. If ingested, DO NOT induce vomiting. Call physician immediately.

Product information contained herein are presented in good faith and believed to be reliable. They do not constitute part of our terms and conditions of sale. It is also not a guarantee, either expressed or implied, that the data are correct or that products described are merchantable or fit for a particular purpose as methods of use are beyond our control. Customer should determine the suitability of our materials and installation recommendations before usage. Manufacturer’s sole responsibility shall be to replace that portion of any product that proved to be defective.

SeamStitch Polyurethane Caulk

Technical Data

Property Value Test Method
ColorLight Gray
Density9.2 ± 0.2 pounds/gallon
Dry TimeDry to touch: 6 hours.
Tack Free: 8-12 hours
Retouch 12-16 hours.
Elongation150% ±50D-2370
Flash Point80°F
Hardness69±5 Shore AD-2240
Permeability0.02 perms/in
Packaging5 gallon pail
Tensile Strength240 psi ±25D-2370
Shelf Life90 Days @ 40°F-90°F
Solids by Weight67%±2ASTM D1644
Service Temp-50°F to 200°F
Viscosity30,000 ± 10,000 cPsBrookfield
Water Absorption2.4%