Polyurethane coatings are typically solvent-based and come in two main types: aromatic (UV-stable) and aliphatic. Urethane has good mechanical properties and high abrasion resistance, and tensile strength. They are most effectively used against hail, where the surface is exposed to heavy traffic. If you or someone you know may be in need of a professional polyurethane roof coating, be sure to contact Classic Roofing for a free quote today! Continue reading for the pros and cons of choosing to go with a polyurethane roof coating.
Polyurethane roof coatings are among the strongest and most durable elastomeric coatings available in the industry. They are most commonly used for sprayed-in-place polyurethane foam insulation as well as other commercial roofing substrates including modified bitumen, single-ply, EPDM, smooth/gravel BUR, and concrete roof decks. There are some important factors to consider when it comes to choosing this particular chemistry. Below, we will explain some of the key strengths and weaknesses of deciding to go with a polyurethane roof coating.
Pros of A Polyurethane Roof Coating
Aliphatic or Aromatic?
There are two types of polyurethane roof coatings: aliphatic and aromatic. Each type is best suited for specific roofing environments and applications. Aliphatic polyurethane coatings are UV stable, hold color longer, resist dirt pick-up, and are typically used as a top coat. Aromatic polyurethane coatings are not as UV stable, cost less, and are most commonly used as a base coat in most systems.
Durability and Flexibility:
Polyurethane roof coating systems form an incredibly durable and flexible monolithic membrane layer. They can effectively withstand the daily expansion and contraction of roof structures as well as the damaging effects of ponding water. They are also more impact-resistant than other coating materials, making them ideal for use on roofs with high-traffic areas.
Adhesion Qualities:
Polyurethane coatings are best known for having outstanding adhesion. They will fully adhere to most conventional commercial roofing substrates including metal, modified bitumen, built-up roofs, spray polyurethane foam, concrete roof deck, EPDM, TPO, and other single-ply membranes.
UV Stability:
Polyurethane roof coating systems are highly reflective and UV stable. This means building owners and facility managers can save money by reducing cooling costs during the hot summer months. Minimizing the sun’s impact on the roofing surface not only helps to sustain lower energy costs, but it also reduces internal building temperatures and prolongs roof life.
Cons of A Polyurethane Roof Coating
Produces a Strong Odor:
A polyurethane roof coating emits a strong, xylene-based odor. While this odorous vapor is not harmful, it can be quite unpleasant for a building’s occupants. For buildings that have a fresh air intake HVAC system, we recommended it be set to recirculate air from within the building, or turned off completely during the installation process.
Challenging to Spray:
As with any solvent-based coating, polyurethane roof coatings can be challenging to spray and difficult on hydraulic spray equipment. Issues during the installation process are less likely to occur if the spray equipment is properly cleaned and maintained.
Shorter Shelf Life:
Single-component polyurethane coatings are constantly curing—even in the pail. Plural-component polyurethane coatings will not cure until mixed.
When it comes to the suitability and performance of a roof coating, it’s important to understand the strengths and weaknesses of the chemistry. Polyurethane roof coatings are a highly effective roofing solution. There’s a number of key factors to consider when it comes to choosing the best polyurethane roof coating system for a commercial roofing environment. If you’ve decided to choose to go ahead with a polyurethane roof coating, contact Classic Roofing to have the job done quickly and easy for any building owner. Call today!
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