Polyurethane sealants deliver superior adhesion, long-term flexibility, and excellent durability across construction, automotive, industrial, and metal bonding applications. Designed to withstand movement, vibration, moisture, and weather exposure, PU sealants provide a paintable, waterproof, and highly versatile solution for sealing and bonding a wide range of materials, including concrete, metal, wood, plastic, and composites.
Compared with silicone or acrylic sealants, polyurethane offers stronger adhesion, higher tear strength, and better performance on porous substrates, making it ideal for structural bonding and expansion joints.
For additional options across silicone, acrylic, hybrid, and specialty chemistries, visit our Caulk & Sealants parent category.
What Is Polyurethane Sealant?
A polyurethane sealant is a one-component, moisture-curing, elastic sealing and bonding material engineered for high-strength adhesion and long-lasting flexibility. It forms a tough, durable, waterproof seal that adheres strongly to porous and non-porous substrates. PU sealants are widely used in construction, automotive sealing, metal fabrication, and structural joints due to their:
- High elasticity (accommodates joint movement)
- Superior mechanical strength
- Excellent waterproofing and weather resistance
- Strong adhesion to concrete, metal, wood, plastics, and composites
- Paintability for seamless finishing
Compared to silicone, polyurethane is stronger, more abrasion-resistant, and better for load-bearing applications, while still providing flexibility and durability.
Key Features & Benefits
Polyurethane sealants in this category share these core advantages:
- Strong multi-material adhesion (metal, concrete, wood, plastics, composites)
- Permanent elasticity to absorb movement and vibration
- Weatherproof & waterproof performance for indoor/outdoor use
- Paintable finish after full cure
- Low shrinkage and stable curing
- Durable, long-lasting seals for construction and automotive applications
Where to Use Polyurethane Sealants?
Polyurethane sealants are ideal for a wide range of construction, automotive, and industrial applications, including:
- Concrete expansion and control joints
- Metal, aluminum, and sheet-metal assemblies
- Wood, composite, and general construction bonding
- Window, door, and façade perimeter sealing
- Automotive seam sealing, repairs, and glazing
- RV, trailer, and vehicle roof joints
- Flooring, decks, driveways, and pedestrian areas
- Prefabricated building joints and structural connections
- Industrial equipment, ducts, and ventilation components
Polyurethane Sealant Products
Stanley S360 Seal & Grab Ultra Fast Cure – Polyurethane Sealant & Adhesive
A high-modulus, multipurpose PU sealant offering strong adhesion and permanent flexibility. Ideal for construction bonding, sheet metal seams, automotive applications, and general indoor/outdoor sealing. Non-sag, paintable, and resistant to dirt pickup.
Explore Stanley S360 Seal & Grab Ultra Fast Cure
Stanley S362 Specialty Self Leveling Polyurethane Sealant – Sausage, 20.3 oz
A one-component, self-leveling PU sealant designed for horizontal joints, concrete slabs, expansion joints, industrial floors, sidewalks, and driveways. Provides ±25% movement capability, smooth flow, and a paintable finish.
Explore Stanley S362 Specialty Self Leveling Sealant Sausage
Akfix P635 Construction Polyurethane Sealant – Low Modulus
A flexible, low-modulus construction PU sealant for expansion joints, prefabricated elements, PVC jambs, façade joints, and ventilation systems. Bubble-free curing, dirt-resistant, CE certified, and safe for indoor/outdoor use.
Explore Akfix P635 Construction Polyurethane Sealant
Akfix 647FC Fast Curing Polyurethane Seam Sealer – White
A fast-curing, sandable, and paintable PU adhesive designed for automotive seam sealing, RV roof repair, metal bonding, and construction applications. Non-sag and compatible with manual or pneumatic caulking guns.
Explore Akfix 647FC Fast Curing White Seam Sealer Automotive – Polyurethane Adhesive
Akfix Polyurethane Windshield Adhesive – Black
A high-modulus, fast-curing PU adhesive for direct glazing and windshield replacement. Delivers excellent initial grab, high mechanical strength, and professional-grade bonding for automotive glass installation.
Explore Akfix Polyurethane Windshield Adhesive - Black
Akfix P645 Automotive Seam Sealer – Polyurethane, Multiple Colors
A durable, flexible, and brush-on PU seam sealer ideal for auto body seams, metal joints, RV repairs, and structural construction applications. Sandable, paintable, and engineered for high vibration resistance.
Explore Akfix P645 Automotive Seam Sealer - Metal Automotive & Construction Polyurethane Sealant
Frequently Asked Questions (FAQs)
Is polyurethane sealant waterproof?
Yes. PU sealants provide long-term waterproofing and are excellent for exterior use, concrete floors, roofing, metal seams, and building envelopes.
Can polyurethane sealant be used in bathrooms, tubs, or showers?
Yes, PU sealant is suitable for bathroom edges, tubs, and showers, but not for permanently submerged areas. For aquariums or underwater applications, silicone is required.
What’s the difference between polyurethane and silicone sealant?
Polyurethane offers stronger adhesion, better abrasion resistance, and is ideal for construction and structural bonding. Silicone offers superior water immersion resistance and is preferred for fully wet environments.
Is polyurethane sealant paintable?
Yes. PU sealant can be painted once fully cured, making it ideal for architectural and finishing work.
How long does polyurethane sealant take to cure?
Cure time varies by product, but most PU sealants form a skin within 30–60 minutes and fully cure within several days, depending on humidity and joint depth.
Does polyurethane sealant shrink or crack?
Quality PU sealants have low shrinkage and maintain flexibility, preventing cracking in moving joints.
Can polyurethane sealant bond metal, plastic, and concrete?
Yes. PU sealants are highly compatible with metal, PVC, composites, and all standard construction substrates.
Is polyurethane sealant suitable for automotive applications?
Yes. Products such as polyurethane seam sealers and windshield adhesives are engineered for vehicle bodywork, metal seams, and vibration-prone areas.
Does polyurethane sealant resist mold or mildew?
While PU sealant is moisture-resistant, it is not mold-proof. For areas with constant moisture exposure, proper ventilation is recommended.
Is polyurethane sealant durable outdoors?
Yes. PU sealants perform exceptionally well outdoors, resisting UV, weathering, and temperature fluctuations.