At a glance, coatings, adhesives, and sealants might seem interchangeable, but on the roof, each serves a distinct purpose. Understanding the difference is what separates a temporary fix from a long-term solution, and a long-lasting roof from a roof that will eventually fail.
At Big Rock Supply, we stock a full range of products across all four categories, giving contractors the flexibility to choose the right solution for every job, whether it’s commercial or residential, repair or full-system protection.
These products all play a role in extending roof life and protecting against elements such as UV exposure, standing water, temperature swings, and wind. The key is knowing when and where to use each one.
Why These Products Matter
Roof systems take a beating year-round. Without protection, materials degrade quickly under sun exposure, moisture intrusion, and thermal movement.
Coatings and sealants act as the first line of defense, creating a barrier that protects the roof membrane. In warmer climates, reflective coatings can reduce surface temperatures and lower energy costs. In wetter regions, waterproofing takes priority, and with good reason.
While these materials do require maintenance and reapplication over time, they are far more cost-effective than addressing structural damage caused by neglect.
The Gist
What Are Roofing Sealants?
Sealants are designed to block moisture and air infiltration. They remain flexible over time, allowing them to move with the roof as it expands and contracts.
Best for:
- Flashings
- Seams and joints
- Penetrations (vents, pipes, skylights)
Common Types:
- Acrylic Sealants: Cost-effective, UV-resistant, easy to apply
- Silicone Sealants: Superior waterproofing, ideal for ponding water
- Polyurethane Sealants: Strong adhesion and durability
- Bituminous Sealants: Asphalt-based, great for traditional roofing systems
What Are Roofing Coatings?
Coatings are applied across larger surface areas to protect and extend the life of the entire roof system.
Best for:
- Full-roof restoration
- UV protection
- Reflectivity (cool roof systems)
- Waterproofing large surfaces
Common Types:
- Acrylic Coatings: Reflective and cost-effective
- Silicone Coatings: Excellent for waterproofing and ponding water
- Aluminum Coatings: UV-resistant with reflective properties
- Polyurethane Coatings: High durability and impact resistance
What Are Roofing Adhesives?
Adhesives are used to bond materials together, providing structural integrity to the roofing system.
Best for:
- Attaching insulation boards
- Securing membranes (TPO, EPDM, PVC)
- Installing flashing components
Types of Adhesives:
- Low-rise foam adhesives
- Solvent-based adhesives
- Water-based adhesives
What are Roofing Caulks?
Caulks are similar to sealants but are typically used for smaller, more precise applications and quick repairs.
Best for:
- Small cracks and gaps
- Detail work
- Residential roofing repairs
Common Types:
- Butyl Caulks: Strong adhesion, good for metal
- Latex Caulks: Easy to apply, paintable
- Polyurethane Caulks: Durable and flexible
Key Factors to Consider
No matter which product you’re using, the right choice comes down to the job conditions:
- Color & Reflectivity: Impacts heat absorption and energy efficiency
- Waterproofing Ability: Critical in wet climates or flat roofs
- Material Compatibility: Must match the roofing system
- Flexibility (Elasticity): Handles expansion and contraction
- Durability: Long-term performance under harsh conditions
Solutions from Trusted Brands
At Big Rock Supply, we carry a wide range of products from trusted manufacturers—each offering specialized solutions across these categories.
- Known for high-performance roof coatings and sealants
- Popular for reflective and waterproofing systems
- Variety of emergency repair solutions pertaining to water intrusion and damage
Product Highlights:
502 MS Karna-Flex Sealant:
A high-performance, rubberized mastic specifically engineered for sealing critical areas across a wide range of roof systems. This product has an elastomeric rubber formulation providing long-lasting flexibility and crack resistance. One-component, ready-to-use sealant with no mixing required. Superior adhesion across a variety of surfaces and materials.
19 Ultra Rubberized Flashing Cement: Wet or Dry Emergency Repair
A rubberized elastomeric formulation for superior flexibility and durability that can bond to wet or dry surfaces, even under damp conditions. This product offers adhesion with resistance to sag at high temperatures, and comes in a graduation for seasonal applications.
- Offers a wide range of coatings, mastics, and adhesives
- Strong in commercial roofing applications
Product Highlights:
9600 STS Moisture Cure Joint Sealant:
A 100% solids non-shrinking moisture cure urethane sealant intended for sealing large joints and roof termination bars. This product is solventless and has diverse adhesion to a variety of surfaces.
8800 Universal Single-Ply Adhesive
A water based contact adhesive for securing a variety of surfaces. This product is fast drying with aggressive tack, and bonds instantly without risk of flammability.
6000 White Universal Thermoplastic Roof Coating
A solvent-based Terpolymer coating intended for the repair and restoration of a variety of surfaces. This product has ultra-low moisture permeability providing excellent ponding water resistance, and dries with almost no over-spray. Designed with energy efficiency in mind.
- Specializes in adhesives and bonding solutions
- Ideal for membrane attachment systems
Product Highlight:
Millennium Sprayable Single-Ply Bonding Adhesive:
A spray-applied contact adhesive for single-ply membranes, specifically designed for use with EPDM, TPO, and fleeceback membranes. Fast-drying formula and two-sided application to both membrane and substrate, this product offers efficient installation.
- Known for low rise foam, bonding adhesives, and fastening systems.
- Predominantly used in commercial roofing systems
Product Highlights:
OMG OlyGlu: TPO and EPDM Membrane Adhesive
A canister-applied membrane adhesive designed for bonding TPO and EPDM roofing membranes in commercial roofing systems. Through spray application, this product helps improve installation speed and coverage. Available at Big Rock Supply in both the small and large canisters.
- Focuses on coating and restoration
- Designed for performance and efficiency
Product Highlight:
Race HPS: High Performance Sealant and Adhesive
High-strength hybrid polymer formula with excellent resistance to UV, moisture, and temperature changes. This product has diverse adhesion and remains flexible after curing.
- Provides specialty coatings and waterproofing solutions
- Strong for niche and demanding applications
Product Highlight:
838 MS: Multi-Purpose Sealant
Hybrid moisture-cure elastomer sealant made from 100% solids, and is free of solvents and isocyanate. Diverse adherence with minimal sag with strong vertical hang. This product can be poured, extruded, or brushed.
Gear Up & Get Going with Big Rock Supply
Every roof is different, and every job calls for the right combination of products.
Whether you’re sealing a penetration, restoring a full system, bonding materials, or handling detailed repairs, Big Rock Supply has the inventory to support you from start to finish.
No matter the application, we’ve got the products and the brands you trust to get the job done with efficiency.