Sikaflex 1a Kit One Component Polyurethane Sealant - Durable, Flexible

In this review the AWF PRO Sikaflex 1a Kit is evaluated as a practical sealant package for contractors and DIYers who need a reliable, flexible polyurethane for exterior joints. The bottom line: this kit is best for users who require a high performance, non sag sealant supplied in five 20 oz sausage cartridges plus a heavy duty caulk gun, and the single biggest reason to buy is its broad adhesion and durability in damp concrete and weather-exposed applications. The review focuses on real useability, coverage expectations, and where its elasticity and standards compliance matter most.

Key Features

• One component, moisture cured: ready to use without mixing, which simplifies on-site application and speeds up work on both vertical and horizontal surfaces.
• High elasticity: cures to a flexible sealant with approximately +/- 35% movement capacity, useful for joints that experience thermal or structural movement.
• Non sag formula: stays in place on vertical joints and fillets, reducing the need for backer rod or excessive tooling during installation.
• Wide adhesion: bonds to most construction materials without a primer, saving prep time for common substrates like concrete, masonry, and metal.
• Complete kit: includes five 20 oz aluminum gray sausages and a heavy duty 20 oz caulk gun, providing immediate value and the tools needed to start the job.
• Standards compliant: meets ASTM C-920 and federal and Canadian specifications, giving confidence for professional and regulated projects.

Who It's For

The Sikaflex 1a Kit suits builders, maintenance crews, and experienced DIYers working on windows, door frames, small joints, flashing details, and concrete seams where a durable, weather-resistant seal is required. Its ability to cure in damp or green concrete makes it a good choice for projects that cannot wait for fully dry substrates.

It is less appropriate for very deep joints over 1/2 in, or for users who need a colored match beyond the provided aluminum gray; in those cases a different product formulated for deep fill or specific color palettes would be better.

Pros & Cons

Pros

• High performance polyurethane provides excellent adhesion and weather resistance.
• Flexible +/- 35% movement retention reduces the chance of cracking in variable joints.
• Kit includes five 20 oz sausages plus a heavy duty caulk gun for immediate use and good value for the quantity.
• Works on damp or green concrete and meets major specifications for professional use.

Cons

• Maximum recommended sealant depth is 1/2 in, so it is not intended for deep joint applications.
• Only supplied in aluminum gray which may require paint or alternative sealants for aesthetic color matches.

Specifications

Product type	One component polyurethane sealant kit
Contents	Five 20 oz aluminum gray sausage cartridges and one heavy duty 20 oz caulk gun
Movement capability	Approximately +/- 35% elasticity
Max sealant depth	1/2 in
Surface use	Vertical and horizontal joints, windows, door frames, fillets
Standards	Meets ASTM C-920, Federal TT-S-00230C Type II, Canadian CAN/CGSB 19.13-M87

Our Verdict

The AWF PRO Sikaflex 1a Kit is a practical, value-oriented package for professionals and competent DIYers who need a reliable, high performance, non sag polyurethane sealant for exterior joints. Its strong adhesion, weather resistance, and included caulk gun make it a smart buy for small to medium joint work, though users with deeper joints or precise color needs should consider alternatives. Overall it delivers solid value for most construction sealing tasks.

Frequently Asked Questions

Can Sikaflex 1a be used on damp concrete?
Yes, it can be used in green and damp concrete applications and is formulated to cure in such conditions.

How deep can the sealant be applied?
It is designed for joints where maximum depth of sealant will not exceed 1/2 in; deeper joints require a different product.

Does the kit include an applicator?
Yes, the kit includes one AWF 2100 heavy duty 20 oz caulk gun along with five 20 oz sausage cartridges.