One of the technical questions St. Louis homeowners ask is how thick their epoxy floor should be. It’s a smart thing to consider because thickness does matter—but not in the way most people think. A thicker coating isn’t automatically better if the prep work underneath is poor.
Understanding Mil Thickness
Epoxy Thickness: Epoxy thickness is measured in mils (one mil equals one-thousandth of an inch). A typical residential garage floor system might be anywhere from 10 to 40 mils thick when fully cured, depending on how many coats are applied and what products are used.
DIY Kits: Often result in coatings under 10 mils because the low-solids products thin out significantly as solvents evaporate.
Professional High-Solids Systems: Build more thickness per coat because there’s more actual resin staying on the floor.
Key Point
A 30-mil epoxy coating on poorly prepped concrete will fail faster than a 15-mil coating on properly ground, profiled, and cleaned concrete. Thickness helps with durability and chemical resistance, but only if the bond to the slab is solid.
