Types Of Roofing Coatings
Below is information on all the Roof Coatings. Before applying a roof coating, inspect the roof for damage.
Before buying and installing a roof coating, make sure it’s legal in your area. Certain coatings are regulated for environmental and health reasons.
Roofing Coatings
Bituminous Asphalt Roof Coatings:
Asphalt or coal tar pitch is the primary waterproofing component in bituminous coatings.
Cool Roof Coatings:
A cool roof coating reduces the amount of heat absorbed by the roof by reflecting more sunlight and increasing thermal emittance than traditional coating materials.
White roof coatings and reflective roof coatings are “cool” roofing materials.
Elastomeric Roof Coatings:
Elastic elastomeric coatings can stretch and shrink without damaging the substrate.
In this way, they can compensate for structural movement, thermal expansion, and contraction of the roof membrane. The majority of non-bituminous roof coatings are elastomeric.
Coatings that do not expand and contract with the roofing material (for example, an asphalt coating on an asphalt roof) will split and crack when exposed to extreme temperature changes and humidity.
Using Fibered Coatings:
Fibered coatings contain cellulose or fiberglass fibers in their formulation. The fibers are typically 14 to 1 inch long.
Adding fibers to the roof coating improves its durability and flow resistance (improving its performance when applied to steep slopes or flashings).
Because the fibers reduce the material’s elasticity, they are usually reserved for non-elastomeric coatings.
Polymer Modified Roof Coatings:
Unmodified bituminous coatings are improved by adding a bitumen-compatible polymer, such as styrene-butadiene-styrene.
Polymer-modified coatings are more flexible, last longer, and cost more than unmodified coatings. The term “rubberized” is often used in this context.
Polymeric Coatings:
Polymeric Coatings are made of a variety of synthetic resins (polymers).
Other polymer-based coatings include acrylics, silicones, and polyurethanes, the most widely used in the US.
Roof Coatings that Reflect Light:
A reflective roof coating is specially formulated to reflect the sun’s rays. Reflective coatings in white, aluminized, or other colors are common.
A reflective coating applied to a black EPDM roof can reduce the roof’s average afternoon temperature by up to 60°F (34°C) in the summer.
Rubberized Roof Coatings:
Rubberized Roof Coatings are a type of rubberized roof coating. See “Polymer-Modified Roof Coatings” in the preceding section for examples of synthetic rubber in bituminous coatings.
White Roofing Coatings:
A white coating is just that: a white coating. White coatings are often described as “cool” and “reflective.”
White is the most common polymeric coating color most white roof coatings contain titanium dioxide. It’s also the priciest.
Types Of Coatings According to Materials:
Acrylic Coatings:
Water, calcium carbonate (or another extender pigment), acrylic polymer resin, and titanium dioxide are the most commonly used ingredients.
Acrylic coatings come in various formulations and can be applied to virtually any surface. Not all substrates and coatings are suitable for each other.
• Incompatible substrates include silicone coatings and built-up roofs with gravel surfaces.
• White, tan, gray, and other colors are used.
• Yes, elastomeric.
• The body’s chemical resistance is limited.
• Unsatisfactory Ponded Water Handling
Aluminum-Based Coatings:
It contains mineral spirits (or another solvent), asphalt, aluminum powder/flakes (30% weight), and perlite (or other filler).
Acceptable Substrates: Smooth asphalt built-up roofing, modified bitumen, metal, and pre-applied asphalt coatings.
Asphalt Cutting-Away Coatings:
This mixture contains asphalt and mineral spirits primarily.
Acceptable Substrates: Smooth asphalt built-up roofing, modified bitumen, metal, and pre-applied asphalt coatings.
Asphalt Emulsion Coatings:
The main ingredients are water, asphalt, and bentonite clay (or other stabilizers).
Acceptable Substrates: Smooth asphalt built-up roofing, modified bitumen, metal, and pre-applied asphalt coatings.
Butyl Coatings:
Alkyl chloride, petroleum resin, polybutene, titanium dioxide, styrene-butadiene-xylene.
This application accepts metal, spray polyurethane foam, smooth-surfaced built-up roofing, modified bitumen, EPDM, PVC, and TPO substrates.
Unacceptable substrates include gravel-surfaced roofing and silicone coatings. Material compatibility checks on product data sheets should be standard.
Coal Tar Pitch Coatings:
It contains refined coal tar pitch, aromatic solvent, and Fuller’s earth (or another stabilizer)
Acceptable construction substrates: smooth coal tar pitch built-up roofing, concrete
The coating cannot be applied to asphalt roofing, single-ply membranes, spray polyurethane foam, or existing non-coal tar pitch coatings.
Coatings with Polyurethane:
The main ingredients are:
• Trimethyl benzene.
• Aromatic hydrocarbons.
• Calcium carbonate (or another extender pigment).
• Xylene (for example, formulations vary).
Substrates include polyurethane foam, EPDM, Hypalon, PVC, TPO, smooth-surfaced built-up roofing, metal, modified bitumen, and concrete.
Due to its UV degradation, it is not suitable for use as a standalone roof surface coating.
This base coat is compatible with aliphatic polyurethane and other UV-resistant coatings. A less expensive aliphatic polyurethane.
PUMA Coatings (Polyurethane Modified Acrylic):
TiO2 (or another prime pigment), barium sulfate, and other additives as needed (for example, formulations vary).
This coating outlasts standard acrylic coatings. The coating chemistry combines acrylic and polyurethane.
SEBS Coatings:
Aluminized styrene/butadiene copolymer, calcium carbonate, mineral spirits, hydrocarbon resin (for example, formulations vary).
Acceptable substrates include Hypalon, metal, TPO, and others with a compatible base coat.
Silicone Coatings:
This product contains mineral silica, titanium dioxide (or another prime pigment), petroleum hydrocarbon distillates, and methyl Maximino silane (for example, formulations vary).
The following materials are acceptable: metallic substrates, EPDM and Hypalon membranes, PVC and TPO roofing membranes, and spray polyurethane foam.
Asphalt or coal tar pitch roofing (with the proper primer) is not acceptable, nor is roofing with a gravel surface.
Other than silicone adhesive or silicone gel. As a result, most old silicone coatings must be removed and replaced with new ones, which is more expensive.
Fabric reinforcement is required in many places, including flashings, angle changes, and roof component or section joints.
Priming is almost always required before painting. It is possible to apply silicone coatings to clean concrete and silicone coatings without priming.
Soy Coatings:
Some polymers are made from soy, while others are dependent on the coating’s primary chemistry, which is usually polyurethanes or acrylics.
Roofing coatings based on soy are similar to salad dressings that claim to be made with olive oil but contain half canola oil and only 5% olive oil.
Preparing a soy-based coating requires knowledge of the final product’s chemistry.
Soy-based coatings are appealing because they contain a portion of a renewable resource rather than a petroleum-based source.