Silicone roof coatings are generally considered superior to acrylic coatings for flat roofs, especially in areas prone to ponding water or needing high UV resistance. While acrylic coatings offer good protection and are more budget-friendly, silicone coatings provide enhanced durability, weather resistance, and longevity.
- Silicone’s Superior Durability and Weather Resistance:
Silicone coatings are known for their exceptional resistance to UV degradation, extreme temperatures, and harsh weather conditions. They are also highly water-resistant, making them an excellent choice for flat roofs prone to ponding water.
- Acrylic’s Cost-Effectiveness:
Acrylic coatings are a more affordable option compared to silicone, making them a viable choice for budget-conscious projects. They offer good waterproofing and protection against the elements. Not nearly as effective to ponding water, therefore, this should not be installed on a low slope roof and its more compatible with higher slopes
- Silicone’s Resistance to Ponding Water:
One key advantage of silicone is its superior resistance to ponding water. Acrylic coatings can break down over time when exposed to prolonged periods of standing water, while silicone’s non-water-based formula makes it better suited for such situations.
- Acrylic’s Ease of Application:
Acrylic coatings are often easier to apply than silicone, making them a good choice for DIY projects or smaller roofing jobs.
- Silicone’s Longevity:
Silicone coatings offer a longer lifespan than acrylic coatings, often lasting longer than 20 years with proper maintenance (assuming you have 2 coats with primer on a optimal conditioned roof membrane…this will not apply on severely deteriorated roofs or if there was already a coating installed) . This makes them a more long-term investment for flat roofs.
- For optimal protection, durability, and resistance to ponding water, especially in challenging climates, silicone roof coatings are the preferred choice for flat roofs.
- If budget is a primary concern, acrylic coatings offer a cost-effective solution with good performance for many more sloped flat roof applications.
- Consider the specific needs of your roof, climate, and budget when making your decision.
Silicone Roof Coating
Silicone coatings were introduced throughout the 1960s and ‘70s. They were used primarily in spray foam roofing applications but eventually evolved into a suitable coating solution for a variety of other commercial roofing substrates including metal, modified bitumen, built-up roofs, EPDM, TPO, PVC, and concrete.
Silicones are the most widely used coating material in modern commercial roof restoration. They are best known for their superior UV stability and resistance to ponding water. Silicones are a solvent-based material, meaning they are less susceptible to colder temperatures and therefore have a broader application window than water-based (acrylic) coatings.
Most of today’s silicone coating formulations have a solids content of 90% or greater, meaning less liquid material is used during application to achieve the required dry film thickness.
The primary drawbacks of silicone coatings are they can be challenging to spray, accumulate dirt, and are extremely slippery when wet. If foot traffic is expected on a silicone system, we highly recommend incorporating a walk path system to provide a slip-resistant surface.
Acrylic Roof Coating
Acrylic roof coatings have been around since the 1950s and remain a popular choice in the commercial roof restoration industry. They are suitable for use on a variety of substrates including metal, modified bitumen, built-up roofs, EPDM, TPO, PVC, concrete, and spray polyurethane foam.
Acrylic coatings are best known for being cost-effective, UV resistant, environmentally friendly, and easy to work with. Unlike silicones, acrylics are easy to clean up and are less harsh on application equipment.
Although acrylics are suitable for use on a variety of substrates, we highly recommend they only be used on steep-slope metal roofs where ponding water is not an issue. As a water-based material, acrylics do not hold up well to standing water.