Deciding Between Acrylic and Silicone Roof Coatings
Acrylic or silicone roof coatings: which one is better? It's a question we encounter now and then, and the answer isn't always straightforward. Each material has its own advantages and drawbacks, offering a variety of money-saving and energy-efficient benefits, while extending the lifespan of aging commercial roofs.
However, in the ongoing debate of acrylic vs. silicone roof coatings, selecting the most suitable option hinges on several factors. Below, we provide an overview of both acrylic and silicone roof coatings, and delve into how they compare across several key aspects:
Cost
Longevity
Reflectivity
UV Stability
Optionality
Resistance to Ponding Water
Application & Clean-Up
Environmental Impact
Aesthetics
Acrylic Roof Coating
Having been around since the 1950s, acrylic roof coatings are very popular for commercial roof restoration. They find utility across various substrates, including metal, modified bitumen, built-up roofs, EPDM, TPO, PVC, concrete, and spray polyurethane foam.
Acrylic coatings are renowned for their cost-effectiveness, UV resistance, environmental friendliness, and ease of application. Unlike silicones, they are simpler to clean up and gentler on application equipment.
While acrylics are compatible with various substrates, they are best suited for sloping metal roofs without ponding water issues. Their water-based nature renders them unsuitable for standing water conditions.
Acrylic systems lose thickness over time and may freeze at colder temperatures, necessitating installation at 50°F or above for optimal adhesion.
Silicone Roof Coating
Silicone coatings made their debut in the 1960s and '70s, initially finding prominence in spray foam roofing applications. Over time, they evolved into a viable coating solution for a myriad of commercial roofing substrates, including metal, modified bitumen, built-up roofs, EPDM, TPO, PVC, and concrete.
Known for their outstanding UV stability and resistance to ponding water, silicones have become a common material for modern commercial roof restoration. Being solvent-based, they boast a wider application window than their water-based (acrylic) counterparts which is rarely relevant in Central Florida.
Most contemporary silicone coating formulations feature a solids content of 90% or higher, requiring less liquid material for achieving the requisite dry film thickness.
However, silicone coatings are very expensive, present challenges during application, tend to attract dirt, and pose slip hazards when wet. Incorporating a slip-resistant walk path system is advisable for areas expecting foot traffic on a silicone-coated surface.
Comparing Acrylic vs. Silicone
Having outlined the basics of acrylic and silicone coatings, let's compare the two materials across different parameters in the acrylic vs. silicone roof coating comparison:
Cost
Acrylic coatings come at a lower price point compared to silicones, making them a more economical choice overall.
Longevity
While many factors influence coating longevity, silicones typically outlast acrylics, due to their better UV and moisture resistance. However, acrylics can be re-coated for additional longevity.
Reflectivity
Both acrylic and silicone coatings boast thermal reflectance ranging between 80-90%, offering comparable performance in this aspect.
UV Stability
Silicones are better than acrylics in UV performance, retaining their integrity without losing thickness.
Optionality
Although silicone coatings can be a good option in some circumstances, they limit the types of coatings an owner can use in the future. In some cases, the silicone has to be removed in order to install different coating systems. Acrylic coatings can be coated with other materials including silicone down the road.
Resistance to Ponding Water
Silicones are better at resisting ponding water making them ideal for flat roofs prone to standing water conditions.
Application & Clean-Up
Acrylic coatings are easier to install and clean up, posing fewer challenges than silicones, which require mineral spirits for cleanup.
Environmental Impact
Acrylic coatings, being water-based, are considered more environmentally friendly.
Aesthetics
Acrylic coatings are generally more aesthetically pleasing over time, as they resist dirt accumulation better than silicones, which may become unsightly with prolonged exposure.
Which Is Better?
In the acrylic vs. silicone roof coating debate, acrylicsemerge as the frontrunner in terms of waterproofing and UV stability. However, selecting the right coating hinges on several critical factors:
When to Use Acrylic Coating:
Steep-slope metal roofs
Application temperatures above 50°F
Prioritizing prolonged aesthetic appearance
Ease of application and cleanup
Environmental considerations
Cost-effectiveness
When to Use Silicone Coating:
Flat roofs prone to ponding water
Emphasizing waterproofing
Applications in colder temperatures
Prioritizing UV stability, durability, and longevity
Aesthetic concerns are secondary
Contact us to schedule a free onsite roof evaluation to determine if our roof coating system is a good fit for your roofing needs.