Elastomeric Coating: Flexible Waterproofing & Protective Coating Systems
Elastomeric Coating: Flexible Waterproofing & Protective Coating Systems
Elastomeric coating systems provide flexible, seamless waterproofing and protective surfacing for building envelopes, roofing systems, concrete structures, and HVAC equipment. Characterized by their ability to bridge surface cracks, accommodate structural movement, and maintain watertight integrity through thousands of thermal cycles, elastomeric coatings are the preferred system for exterior walls, flat roofs, parking decks, and any surface where flexibility and long-term waterproofing are the primary requirements. Spray On Coatings offers professional-grade elastomeric coating installation for commercial, industrial, and institutional clients.
What Is an Elastomeric Coating?
An elastomeric coating is any coating that exhibits high elongation at break (typically 100–400% or more) and recovers substantially to its original dimensions after deformation — like a rubber band stretched and released. The term “elastomeric” does not refer to a single chemistry but rather to a performance characteristic that can be achieved through multiple polymer systems including acrylic, polyurethane, polyurea, silicone, and styrene-butadiene rubber (SBR) formulations.
The critical distinction between elastomeric coatings and conventional rigid coatings (like epoxy) is the ability to bridge cracks in the substrate and remain flexible through seasonal temperature swings. While rigid coatings will crack and delaminate when the substrate moves or thermally cycles, elastomeric coatings stretch and recover with the substrate, maintaining continuous waterproofing protection without membrane failure. This crack-bridging ability is quantified by ASTM C1305 (crack resistance) and is a standard specification requirement for elastomeric roofing and wall coating systems.
Types of Elastomeric Coatings
Acrylic Elastomeric Coatings
Water-borne acrylic elastomeric coatings are the most widely used category of elastomeric coating for exterior building surfaces. Applied at 15–30 mils DFT (20–40 mils WFT), acrylic elastomeric coatings provide durable weather resistance, excellent UV stability, breathability (vapor permeability), and crack-bridging capacity for painted masonry, stucco, CMU block, and concrete tilt-wall construction. Acrylic elastomeric formulations have been refined over five decades and represent a mature, proven technology with an extensive track record on commercial and residential buildings across all climate zones.
Silicone Elastomeric Roof Coatings
Silicone elastomeric roof coatings are specifically engineered for flat and low-slope roofing applications where ponding water resistance, UV stability, and long-term flexibility are critical. Silicone’s unique inorganic backbone (-Si-O-Si-) makes it inherently resistant to UV degradation, ozone, and extreme temperature cycles (-80°F to +400°F) that degrade organic polymer coatings. Silicone elastomeric roof coatings maintain ponding water resistance indefinitely — a critical advantage over acrylic coatings that can soften and lose adhesion when continuously immersed. Applied at 20–40 mils over a prepared roof surface, silicone roof coatings create a durable, seamless waterproofing layer that extends roof life by 10–20 years.
Polyurethane Elastomeric Coatings
Polyurethane elastomeric coatings combine the flexibility and crack-bridging of traditional elastomeric systems with the superior chemical resistance and abrasion resistance of polyurethane chemistry. Ideal for concrete waterproofing on plaza decks, balconies, parking structures, and bridge abutments, polyurethane elastomeric systems are applied at 40–80 mils DFT over properly prepared concrete with a compatible primer. Traffic-bearing polyurethane elastomeric systems incorporate aggregate-textured wear surfaces for slip resistance and abrasion protection. These systems are frequently the first choice on occupied parking structures and pedestrian plazas where traffic cannot be fully diverted during coating installation.
Polyurea Elastomeric Coatings
Spray polyurea represents the highest-performance category of elastomeric coating — combining polyurea’s exceptional tensile strength and elongation (up to 600%) with a cure speed that enables rapid return to service. For applications requiring maximum crack bridging, impact resistance, and waterproofing integrity under severe mechanical and chemical loading, polyurea elastomeric systems deliver performance that no other coating chemistry can match. Polyurea is the elastomeric system of choice for secondary containment, bridge deck waterproofing, and industrial waterproofing applications where failure consequences are severe.
Elastomeric Coating Applications
Flat and Low-Slope Roofing
Elastomeric roof coatings are a cost-effective alternative to full roof replacement for aging flat and low-slope commercial and industrial roofs. Applied over existing built-up roofing, modified bitumen, single-ply membrane, metal, or concrete roof decks, elastomeric roof coatings seal existing seams and penetrations, reflect solar heat to reduce cooling loads, and provide a new watertight membrane that extends building envelope life by 10–20 years. Cool roof elastomeric coatings with high solar reflectance index (SRI) values qualify for Energy Star certification and can reduce roof surface temperatures by 50–80°F compared to uncoated dark roofing surfaces, significantly reducing air conditioning energy consumption.
Exterior Masonry and Concrete Wall Waterproofing
Exterior masonry walls on commercial buildings, institutional facilities, and residential structures are subject to wind-driven rain infiltration, efflorescence, carbonation, and freeze-thaw damage if left unprotected. Elastomeric wall coatings applied at 20–30 mils DFT create a flexible, breathable waterproofing barrier that prevents water infiltration while allowing water vapor from inside the building to escape outward (breathability), preventing trapped moisture problems. The crack-bridging capacity of elastomeric wall coatings maintains waterproofing integrity even as the masonry substrate develops hairline cracks from thermal movement and structural settlement over time.
Parking Decks and Concrete Structures
Multi-story parking structures represent one of the most demanding environments for any coating system: constant vehicular loading, hot tire abrasion, deicing salt exposure, wide temperature cycles, and structural movement from building live loads. Elastomeric traffic coatings applied to parking deck surfaces protect the structural concrete from chloride-induced corrosion, the primary cause of parking structure deterioration. Traffic-bearing elastomeric systems consist of a primer, elastomeric waterproofing membrane, aggregate-filled intermediate coat for wear resistance, and a slip-resistant topcoat. These systems are specified by structural engineers on new construction and incorporated into remediation programs for aging structures.
HVAC Equipment and Metal Surfaces
Elastomeric coatings for HVAC equipment, metal roofing, and mechanical systems provide corrosion protection, thermal reflectance, and weatherproofing for equipment subject to outdoor environmental exposure. Elastomeric coatings on metal roofing seal seams and fastener penetrations that are primary points of water infiltration on aging metal roof systems and accommodate the significant thermal expansion and contraction of metal panels without cracking or delaminating. HVAC equipment coated with reflective elastomeric systems operates at lower surface temperatures, extending equipment life and reducing heat gain into the building.
Selecting the Right Elastomeric Coating for Your Project
With multiple elastomeric coating chemistries available, selecting the optimal system requires evaluating the substrate type, exposure conditions, traffic loading, desired service life, and budget. For exterior masonry walls and residential roofing, water-borne acrylic elastomeric coatings provide excellent performance at competitive cost. For commercial flat roofing with ponding water concerns, silicone elastomeric roof coatings are the preferred choice. For parking decks and bridge decks with vehicular traffic, polyurethane or polyurea elastomeric traffic coating systems provide the required combination of waterproofing, crack bridging, and abrasion resistance. Our technical team is available to evaluate your specific application and recommend the right system.
Contact Us for Elastomeric Coating Services
Whether your project involves waterproofing a flat commercial roof, protecting a parking structure, or sealing an exterior masonry building, our elastomeric coating specialists have the expertise and equipment to deliver a professional result. We provide free project evaluations and written proposals for all elastomeric coating projects. Contact Spray On Coatings to speak with an elastomeric coating expert today.