Bostik Chem-Calk GPS1 Tan Polyurethane Sealant

Description

Chem-Calk GPS1 is a tan, one-component polyurethane, non-sag sealant for general sealing work on exterior building materials. It is made for roofing details, flashing, soffit and fascia joints, termination bar, and dissimilar substrate sealing.

Chem-Calk GPS1 Benefits

• One-component package removes jobsite mixing and supports standard cartridge application.
• Non-sag body helps the bead stay placed on vertical and overhead joint details.
• Dynamic movement capability supports exterior joints that see temperature and building movement.
• Tan color helps blend with selected construction materials and trim details.
• ASTM C920 and Federal Specification references support project documentation needs.

This sealant is useful when crews need a practical polyurethane bead for general construction sealing rather than a specialty glazing or submerged-service product. It belongs in roofing, exterior envelope, and maintenance work where joint prep is controlled.

Where Chem-Calk GPS1 Fits

• Sealing flashing transitions, soffit edges, fascia joints, and termination bar details.
• General exterior sealing between dissimilar building materials.
• Non-sag vertical joints on prepared construction substrates.
• Repair work where a tan polyurethane sealant is the specified color.
• Maintenance sealing on building envelope details that need movement capability.

Surface Preparation and Use

Apply to clean, dry, sound surfaces. Remove dust, oil, loose coatings, old failed sealant, and contaminants that could interfere with adhesion. Use backer rod where joint depth control is needed and tool the bead while the sealant is workable.

Confirm adhesion on representative materials before production use. Some coatings, plastics, and weathered surfaces need extra testing or primer guidance. For related products, browse Chemical Concepts sealants.

Technical Details and Documentation

Bostik literature describes GPS1 as a one-component polyurethane non-sag sealant that meets ASTM C920 Type S, Grade NS, Class 25, Use NT, and Federal Specification TT-S-00230C Type II, Class A. Review current manufacturer information from Bostik before job approval.

Ordering Help

Confirm color, joint movement, substrate, and exposure before switching sealants on a project. For help choosing between polyurethane, silicone, and hybrid sealants, call (800) 220-1966 or email [email protected].