14 Types of Roof Coatings • Important Facts & Guidelines

By Roof Online Staff • Updated September 17, 2022

Table of Contents

Applying an aluminized roof coating to a built-up roof with a roller.
Applying an aluminized roof coating to a built-up roof with a roller

About This Roof Coating Information

This page provides general information about various types of roof coatings. Most of the information was compiled from a wide assortment of manufacturers’ technical data sheets or material safety data sheets for actual coating products, and should be considered to be representative but not definitive.

This information should not be used if precise values are needed for critical design calculations.

When precision is necessary, always refer to the data sheets of the actual, specific product you intend to use, or contact the technical department of the coating manufacturer.

Roof Coatings on Shingled Roofs

Applying a roof coating to a shingled roof is simply a bad idea and goes against the recommendations of every reputable shingle manufacturer.

In almost no case will a roof coating be suitable for a pitched roof. One important function of shingles is that they allow the roof sheathing to release moisture up through the roof.

The moisture that accumulates in the roof sheathing generally comes from interior humidity which condenses on the underside of the roof sheathing.

Heating and air conditioning lead to different levels of humidity and temperature between the inside of the house and the outside air. These differences lead to condensation.

If you coat the roof, that moisture will have nowhere to go. It will remain trapped in the sheathing, laying the groundwork for dry-rot and mold.

Before You Apply a Roof Coating

It is very important to read the manufacturer’s safety information before working with roof coating materials. Some of these coatings are extremely toxic during application and all manufacturer’s safety guidelines must be followed.

You can find the safety information in the manufacturer’s technical data sheet and material safety data sheets for the actual product you are considering using.

You can find these data sheets online at the manufacturer’s website.

Before purchasing and applying a roof coating material, be sure to check whether a material is legal to use in your jurisdiction. Some types of coatings are subject to environmental and health restrictions.

The manufacturer’s product data sheet will also provide coating application instructions (like whether reinforcement fabric is needed, coverage rate, etc.).

Substrate Preparation for Roof Coatings

When applying roof coatings, remember that virtually all surfaces to be coated must be clean, dry, and free of contaminants such as dirt, oil, grease, delaminated areas of previous coatings, and other debris.

Do not apply roof coatings on wet or damp surfaces.

If you apply a roof coating on a dusty or damp surface, the adhesive bond will not form properly, and the coating will eventually delaminate and fall off. We’ve seen it happen many, many times.

If a primer is recommended by the manufacturer, make sure you apply the primer!

Roof Coatings: General Categories

Bituminous Roof Coatings

Bituminous coatings use asphalt or coal tar pitch as their main waterproofing component.

bituminous roof coating
Asphalt-based bituminous roof coating (image courtesy Mule-Hide Products)

Cool Roof Coatings

cool roof coating is any coating that reduces the amount of heat the roof absorbs from the sun by reflecting a higher proportion of sunlight and increasing thermal emittance as compared to traditional coating materials.

White roof coatings and coatings formulated with other reflective pigments are considered “cool”.

See examples of cool roof coatings on Amazon.

cool roof coating
Cool roof coating (image courtesy National Coatings Corporation)

Elastomeric Roof Coatings

Elastomeric coatings have elastic properties which allow them to stretch and return to their original dimensions without being damaged.

This allows them to accommodate building movement and particularly the thermal expansion and contraction of the roof membrane on which they are applied. Most non-bituminous roof coatings are elastomeric.

Non-elastomeric coatings must have similar expansion/contraction rates as the roofing material they are applied to (an asphalt coating on an asphalt roof, for example), or they will split and crack.

See examples of elastomeric roof coatings on Amazon.

Fibered (Fibrated) Roof Coatings

Fibered coatings are formulated with cellulose or fiberglass fibers. The fibers are typically between ¼ inch and 1 inch long.

The fibers in a roof coating increase tear resistance in the cured coating and resistance to flow during application (improving its performance when applied to steep slopes or flashings).

Generally, only non-elastomeric coatings will be fibered, as the fibers reduce the elasticity of the material.

See examples of fibered roof coatings on Amazon.

Polymer-Modified Roof Coatings

A polymer-modified coating is a bituminous coating that has been formulated with the addition of a bitumen-compatible polymer such as styrene-butadiene-styrene to improve its performance.

A polymer-modified coating will typically be more flexible, longer-lasting, and more expensive than unmodified coatings. Often referred to as “rubberized”.  

Polymeric Roof Coatings

Polymeric coatings are made using any of various synthetic resins (polymers) as the primary waterproofing component.

The most commonly seen polymeric coatings are based on acrylics, silicones, or polyurethanes, but there are several other polymer-based coatings.

Reflective Roof Coatings

A reflective coating is any roof coating formulated to be highly reflective of the sun’s rays.

Typical reflective coatings are white, aluminized, or include special reflective pigments in other colors.

Reflective coatings produce a “cool roof” effect. In the case of a black EPDM roof, for instance, a reflective coating can reduce the normal afternoon temperature of the roof by up to 60°F (34°C).

See examples of reflective roof coatings on Amazon.

Rubberized Roof Coatings

A “rubberized” coating is a bituminous coating that contains a synthetic rubber. See “Polymer-Modified Roof Coatings” above.

White Roof Coatings

A white coating is simply a coating that is white. White coatings are generally considered “cool” or “reflective”.

Most polymeric coatings are available in white. Titanium dioxide is the most commonly used pigment in white roof coatings.

See examples of white roof coatings on Amazon.

Types of Roof Coatings by Coating Material

Acrylic Roof Coatings

acrylic roof coating
Tan acrylic roof coating (image courtesy National Coatings Corporation)

Main Components: (This is an example and actual product formulations will vary) water, calcium carbonate (or other extender pigment) acrylic polymer resin, titanium dioxide (or other prime pigment)

Acceptable Substrates: Acrylic coatings are available in a wide variety of formulations for application on almost every type of substrate. Individual coating products are not applicable to all substrates. It is important to check the product data sheet of the actual product before selecting an acrylic coating.

Unacceptable Substrates: Existing silicone coatings, gravel-surfaced built-up roofs

Colors: White, tan, gray, various other colors

Elastomeric: Yes

Chemical Resistance: Poor

Handles Ponded Water: Poor

Handles Foot Traffic: Poor (some formulations perform better)

Application Method: Brush, roller, or spray

Application Temperature: Above 50°F (10°C)

Notes: Water-based. One of the most inexpensive types of coating. Comes in the widest variety of colors. Does not last nearly as long as some of the other (more expensive) coatings on this list.

Easy to apply. Low VOC. Low toxicity.

See examples of acrylic roof coatings on Amazon.

Aluminum (Aluminized) Roof Coatings

Main Components: Mineral spirits (or other solvent), asphalt, aluminum powder/flakes (up to 30%), perlite (or other filler)

Acceptable Substrates: Smooth-surfaced asphalt built-up roofing, modified bitumen, metal, existing asphalt coatings

Unacceptable Substrates: Coal-tar, single-ply membranes, Kynar®- or Hylar®-coated metal, spray polyurethane foam, gravel-surfacing, existing non-asphalt coatings

Colors: Silver

Elastomeric: No

Chemical Resistance: Poor

Handles Ponded Water: Poor

Handles Foot Traffic: Fair

Application Method: Brush or spray

Application Temperature: Above 40°F (4°C)

Notes: Available fibered or non-fibered. Gives asphalt roofing a reflective surface.

Aluminum roof coatings are used for their “cool roof” effects, and to protect and extend the life of asphalt-based roof systems and roof components, especially modified bitumen.

On gravel-surfaced roofs, it’s very common to use an aluminized roof coating on the base flashings throughout the roof.

See examples of aluminum roof coatings on Amazon.

Asphalt Cutback (Solvent-Based) Roof Coatings

Asphalt cutback roof coating (image courtesy Southwestern Petroleum Corporation)

Main Components: Asphalt, mineral spirits

Acceptable Substrates: Smooth-surfaced asphalt built-up roofing, modified bitumen, metal, existing asphalt coatings

Unacceptable Substrates: Coal tar pitch roofing, single-ply membranes, Kynar®- or Hylar®-coated metal, spray polyurethane foam, gravel-surfacing, existing non-asphalt coatings

Colors: Black

Elastomeric: No

Chemical Resistance: Poor

Handles Ponded Water: Poor

Handles Foot Traffic: Fair

Application Method: Brush or squeegee

Application Temperature: Above 40°F (4°C)

Notes: Available fibered or non-fibered. Used to re-coat and extend the life of asphalt roofs.

Can be thinned to use as a primer.

Can be used to bond asphalt-impregnated felts together when making repairs.

Can be used to adhere roll roofing/modified bitumen cap sheets when making repairs.

Can be used when re-applying gravel to bare spots on gravel-surfaced roofs.  

Asphalt Emulsion (Water-Based) Roof Coatings

asphalt emulsion roof coating
Applying an asphalt emulsion roof coating (image courtesy Western Colloid)

Main Components: Water, asphalt, bentonite clay (or other stabilizer)

Acceptable Substrates: Smooth-surfaced asphalt built-up roofing, modified bitumen, metal, existing asphalt coatings

Unacceptable Substrates: Coal-tar, single-ply membranes, Kynar®- or Hylar®-coated metal, spray polyurethane foam, gravel-surfacing, existing non-asphalt coatings

Colors: Black, brown

Elastomeric: No

Chemical Resistance: Poor

Handles Ponded Water: Poor

Handles Foot Traffic: Fair

Application Method: Brush, roller, or spray

Application Temperature: Above 50°F (10°C)

Notes: Available fibered or non-fibered.

Only used in surface applications or as a base-coat for another asphalt-compatible coating.

Used to re-coat and extend the life of asphalt roofs.

Butyl Roof Coatings

Butyl roof coating
Butyl roof coating (image courtesy EPDM Coatings)

Main Components: (This is an example and actual product formulations will vary) aliphatic hydrocarbon, petroleum resin, polybutene, titanium dioxide, styrene, butadiene, xylene

Acceptable Substrates: Metal, spray polyurethane foam, smooth-surfaced built-up roofing, modified bitumen, EPDM, PVC, TPO

Unacceptable Substrates: Gravel-surfaced roofing, existing silicone coatings. Always check specific product data sheets for material compatibility.

Colors: White, gray, custom colors available

Elastomeric: Yes

Chemical Resistance: Fair

Handles Ponded Water: Excellent

Handles Foot Traffic: Fair

Application Method: Brush, roller, spray

Application Temperature: Above 40°F (4°C)

Notes: Polymeric coating. Solvent based. High VOC. Relatively expensive. Highly elastomeric. Can qualify as a vapor barrier.

Coal Tar Pitch-Based Roof Coatings

Main Components: Refined coal tar pitch, aromatic solvent, Fuller’s earth (or other stabilizer)

Acceptable Substrates: Smooth-surfaced coal tar pitch built-up roofing, concrete

Unacceptable Substrates: Asphalt roofing, single-ply membranes, spray polyurethane foam, existing non-coal tar pitch coatings

Colors: Black

Elastomeric: No

Chemical Resistance: Good

Handles Ponded Water: Good

Handles Foot Traffic: Fair

Application Method: Brush or squeegee

Application Temperature: Above 40°F (4°C)

Notes: May be difficult or impossible to find these days. Coal tar pitch roof coatings are used to re-coat and extend the life of coal tar pitch roofs, which have almost completely disappeared as far as new roofing installations go.

Polyurea Roof Coatings

Polyurea roof coating
Applying a polyurea roof coating (image courtesy Teknos)

Main Components: An isocyanate component is combined with an amine resin blend component at the time of application.

Acceptable Substrates: Concrete, spray polyurethane foam, metal, built-up roofing, modified bitumen, EPDM, PVC, TPO single-ply membranes

Unacceptable Substrates: Gravel-surfaced roofing, existing silicone coatings

Colors: Many colors available

Elastomeric: Yes

Chemical Resistance: Excellent

Handles Ponding Water: Excellent

Handles Foot Traffic: Excellent

Application Method: Spray

Application Temperature: 5°F (3°C) above the dew point and rising

Notes: Cures in seconds, requires special equipment and training to apply. Relatively expensive.

Polyurethane (Aliphatic) Roof Coatings

Polyurethane roof coating (image courtesy Lexis Coatings)

Main Components: (This is an example and actual product formulations will vary) polyoxypropylene glycol, cyclohexane, aliphatic hydrocarbon, titanium dioxide (or other prime pigment), hexamethylene diisocyanate, xylene, ethyl benzene 

Acceptable Substrates: Spray polyurethane foam, EPDM, Hypalon, PVC, TPO, smooth-surfaced built-up roofing, metal, modified bitumen, concrete

Unacceptable Substrates: Gravel-surfaced roofing, existing silicone coatings

Colors: White, gray, various other colors

Elastomeric: Yes

Chemical Resistance: Good

Handles Ponded Water: Fair

Handles Foot Traffic: Excellent

Application Method: Brush, roller, spreader, or sprayer

Application Temperature: Above 40°F (4.45°C), below 100°F (38°C), and more than 5°F (3°C) above the dew point and rising

Notes: Solvent-based. Very UV stable, often used as a top coat over an aromatic polyurethane coating. More expensive than aromatic polyurethane.

Has a strong odor during application.

Polyurethane (Aromatic) Roof Coatings

Main Components: (This is an example and actual product formulations will vary) diphenylmethane diisocyanate, methylene bisphenyl isocyanate, trimethylbenzene, aromatic hydrocarbons, calcium carbonate (or other extender pigment), xylene

Acceptable Substrates: Spray polyurethane foam, EPDM, Hypalon, PVC, TPO, smooth-surfaced built-up roofing, metal, modified bitumen, concrete

Unacceptable Substrates: Gravel-surfaced roofing, existing silicone coatings

Colors: Gray

Elastomeric: Yes

Chemical Resistance: Good

Handles Ponded Water: Fair

Handles Foot Traffic: Excellent

Application Method: Brush, roller, spreader, or sprayer

Application Temperature: Above 40°F (4.45°C), below 100°F (38°C), and more than 5°F (3°C) above the dew point and rising

Notes: Susceptible to UV degradation, it is not acceptable as a roof surface coating by itself (see above).

Used as a base coat beneath an aliphatic polyurethane or other compatible UV-resistant coating. Less expensive than aliphatic polyurethane.

Has a strong odor during application.

PUMA Roof Coatings (Polyurethane Modified Acrylic)

Applying a gray PUMA coating to a parking garage deck (image courtesy Tremco Construction Products Group)

Main Components: (This is an example and actual product formulations will vary) methyl methacrylate, 2-propenoic acid, 2-ethylhexyl ester, titanium dioxide (or other prime pigment), barium sulfate

Acceptable Substrates: Concrete, spray polyurethane foam, metal

Unacceptable Substrates: Consult manufacturer’s technical department.

Colors: White, gray

Elastomeric: Yes

Chemical Resistance: Excellent

Handles Ponded Water: Good

Handles Foot Traffic: Excellent

Application Method: Brush, roller, spray

Application Temperature: Above 40°F (4.45°C), below 100°F (38°C), and more than 5°F (3°C) above the dew point and rising

Notes: PUMA coatings last much longer than typical acrylic coatings. A mixture of polyurethane and acrylic coating chemistry. PUMA coatings are often used to waterproof concrete surfaces that support vehicular traffic, such as in parking garages.

PVDF Roof Coatings (Polyvinylidene Fluoride)

Main Components: (This is an example and actual product formulations will vary) water, N-methyl-2-pyrrolidone, polyvinylidene fluoride resin, acrylic modifier, pigments

Acceptable Substrates: Metal. Other substrates require the application of a compatible base coating.

Unacceptable Substrates: Consult manufacturer’s technical department.

Colors: Various colors available

Elastomeric: Yes

Chemical Resistance: Excellent

Handles Ponded Water: Good

Handles Foot Traffic: Excellent

Application Method: Spray

Application Temperature: Above 60°F (15°C)

Notes: Based on the formulation known as Kynar 500. Very long lasting. Typically applied at the factory.

SEBS Roof Coatings (styrene ethylene butadiene styrene)

SEBS roof coating
SEBS roof coating (image courtesy Mule-Hide Products)

Main Components: (This is an example and actual product formulations will vary) Calcium carbonate, mineral spirits, hydrocarbon resin, styrene/butadiene copolymer

Acceptable Substrates: Hypalon, metal, TPO, other substrates with application of compatible base coat

Unacceptable Substrates: EPDM, KEE, PVC

Colors: White, black, gray, various other colors

Elastomeric: Yes

Chemical Resistance: Fair

Handles Ponded Water: Good

Handles Foot Traffic: Good

Application Method: Brush, roller, spray

Application Temperature: Above 40°F (4.45°C), and more than 5°F (3°C) above the dew point and rising

Notes: Solvent-based. Strong odor during application. Dries quickly. Very compatible with steel roofing. Compared to more common coatings, it has relatively low moisture permeability.

Silicone Roof Coatings

Main Components: (This is an example and actual product formulations will vary) crystalline silica, titanium dioxide (or other prime pigment), petroleum hydrocarbon distillates, methyl oximino silane

Acceptable Substrates: Metal, EPDM, Hypalon, PVC, TPO, existing roof coatings, spray polyurethane foam

Unacceptable Substrates: Asphalt or coal tar pitch roofing (may be possible with appropriate primer), gravel-surfaced roofing

Colors: White, tan, gray, various other colors

Elastomeric: Yes

Chemical Resistance: Good

Handles Ponded Water: Good

Handles Foot Traffic: Poor

Application Method: Brush, roller, spray

Application Temperature: 35°F (1.7°C) and rising

Notes: Silicone is hard for anything else to adhere to. This restricts re-coating options; generally old silicone coatings must either be removed or re-coated with another silicone coating.

Silicone coatings can be much more expensive compared to lower-end acrylic coatings.

Silicone coatings are relatively long-lasting. Silicone coatings can last two or three times as long as most acrylic coatings if properly applied.

Reinforcement fabric is recommended for many applications, especially at flashings, angle changes, and joints between roof components or sections.

Many substrates will need to be primed before a silicone roof coating is applied. Many substrates won’t. It depends on the substrate as well as the specific product. Silicone coating formulations vary from manufacturer to manufacturer.

Always check the product data sheet or contact the manufacturer’s technical department. Application to clean concrete and clean existing silicone coatings can generally be done without priming.

See examples of silicone roof coatings on Amazon.

Soy-Based Roof Coatings

Main Components: Some soy-derived polymers, other components depend on the primary chemistry of the coating, typically polyurethanes or acrylics

Acceptable Substrates: Varies according to the primary chemistry

Colors: White, various other colors

Elastomeric: Usually

Chemical Resistance: Varies

Handles Ponding Water: Varies

Handles Foot Traffic: Varies

Application Method: Brush, roller, spray

Application Temperature: Varies

Notes: Most “soy-based” roof coatings are kind of like salad dressings that are advertised as being made with olive oil, but when you read the ingredients, you find out that half the dressing consists of canola oil and the olive oil is only 5%.

It’s important to check what the chemistry of the actual product is before selecting a soy-based coating.

The attraction of soy-based coatings is that a renewable resource, rather than petroleum, is being used to produce a portion of the material. It’s a lot like adding ethanol to gasoline that way.