Acrylic coating systems are a great solution to restore and protect commercial roofs. There are some important factors to consider when it comes to choosing this particular chemistry. Below, we examine some of the key strengths and weaknesses of an acrylic roof coating.
Reflectivity And Reduced Energy Costs
The roof coating looks like a paint in a can or pail. It has the same viscosity as paint, which makes it brushable or sprayable, or, it can be applied with a roller, just like a house paint. But, it’s a very different material based on a different class of acrylic chemistry. Also, it’s a material that has a unique set of performance criteria. An acrylic elastomeric roof coating is not a paint. Typically a paint does not require resistance to ponding water, reflectivity properties, flexibility at low temperature, ability to expand and contract or resistance to foot traffic. But an elastomeric roof coating does require these properties. The roof is going to sit on a relatively horizontal surface, tolerating many external stresses and water contact for extended time.
These acrylic roof coatings are usually white in color. This white color provides two unique features. First it reduces the temperature of the roof membrane to which it is applied. This reduced temperature coupled with the UV blocking properties of the coating reduces the degradation and deterioration of the roofing membrane enabling it to last longer. This white color also reflects as much as 85% of the heat portion of the sunlight, reducing the heat transfer into the building and reduces air conditioning costs.
The key property required of any roof coating material is durability. Acrylic technology is widely used in exterior applications for industrial coatings, house paints, because of its durability. Durability implies resistance to the effects of UV degradation from the sun. The sunlight strikes a polymer, such as asphalt, the asphalt absorbs some of the radiation, and the polymer begins to vibrate, and break up into smaller pieces. This is the degradation that is associated with the harmful effects of sunlight. This can be seen readily in aged asphalt roofing. When new, it looks OK. However, six months later, there’s a brown chalky residue. This is the result of ultraviolet degradation from the sun. Acrylic polymers are transparent to ultraviolet radiation which means they do not absorb the sun’s destructive radiation. The polymer is not absorbing any of the radiation; it’s reflecting the radiation back into the atmosphere. When that same acrylic polymer is formulated into a roof coating and the UV transmission is measured, there is no transmission. The coating contains UV blocking pigments that reflect this degrading UV radiation and so the roof substrate is protected.
Another advantage of acrylic roof coatings is that they are easy to apply. They are waterborne materials, they’re single component and don’t require two component mixing. Simply stated, they are very easy to work with. They can be applied just like a house paint, by spray, by roller, by brush, by squeegee. They can be cleaned up with water, airless spray units can be rinsed with the same ease that a painter would rinse out after painting with typical latex house paint. They don’t carry any volatile organic compound constraints, they’re not red label, and because they are waterborne there is little concern about shipping and handling. These coating have minimal toxicity, usually no more than a conventional house paint.
From a cost performance standpoint, these acrylic roof coatings are extremely attractive. When compared to other types of coatings used to maintain roofs, acrylics, in terms of the initial cost, are sometimes higher an asphalt emulsion or an asphalt cutback. But when the expected service life of the coatings is considered and life cycle costs are computed, the acrylics come out with the most attractive (lower) life cycle costs.
Post time: Apr-14-2021