What thickness should elastomeric coating be applied?

What thickness should elastomeric coating be applied?

• A. 10 to 20 mils
• B. 1 to 2 mils
• C. 50 to 60 mils
• D. 100 mils

Answer: (A)

The main idea is that elastomeric coatings need enough film thickness to form a durable, waterproof, flexible membrane that can accommodate substrate movement. In practice, about 20 mils of dry film thickness per coat is typical, and many products are specified to be applied around 20 mils per coat, sometimes with a second coat to reach the desired total. So a range of 10 to 20 mils per coat fits the common guidance: it provides sufficient thickness to seal and allow elasticity without becoming so thick that the coating cracks, sags, or traps air. The other options—much thinner, or much thicker—tail off that balance and can lead to poor adhesion, cracking, or unnecessary buildup.

The main idea is that elastomeric coatings need enough film thickness to form a durable, waterproof, flexible membrane that can accommodate substrate movement. In practice, about 20 mils of dry film thickness per coat is typical, and many products are specified to be applied around 20 mils per coat, sometimes with a second coat to reach the desired total. So a range of 10 to 20 mils per coat fits the common guidance: it provides sufficient thickness to seal and allow elasticity without becoming so thick that the coating cracks, sags, or traps air. The other options—much thinner, or much thicker—tail off that balance and can lead to poor adhesion, cracking, or unnecessary buildup.