Epoxy Floor Calculator

Epoxy floor coating is a two-component thermoset system: a resin side based on epoxide groups, most commonly the diglycidyl ether of bisphenol A, and a hardener side that is usually an amine or polyamide. Mixing them starts an irreversible crosslinking reaction, which is why the product has a pot life rather than a shelf life once combined, typically 20 to 45 minutes at 70 degrees F and much shorter as temperature rises. Coverage follows directly from solids content and target film thickness. A theoretical gallon spread at 1 mil dry thickness covers about 1,604 square feet at 100 percent solids, so a 50 percent solids product applied at 4 mils dry lands near the 200 to 250 square feet per gallon figure quoted for garage kits. Metallic and high-build systems deposit more material per pass and drop toward 100 to 150 square feet per gallon. The two variables that most often invalidate a quantity estimate are surface profile and moisture. Rough, porous, or previously patched concrete absorbs coating into voids that contribute nothing to film build, which is why a condition multiplier of 1.15 to 1.30 is applied to the nominal coverage rate. Adhesion depends on mechanical profile, commonly specified in the range of CSP 2 to CSP 3 on the International Concrete Repair Institute scale, produced by diamond grinding or acid etching. Moisture vapor transmission through the slab is the other failure mode: ASTM D4263 plastic sheet testing or a calcium chloride test should precede application, and concrete less than 28 days old is generally too alkaline and too wet to coat. Substrate temperature should sit between 55 and 90 degrees F and at least 5 degrees above the dew point.

Epoxy resin chemistry was developed independently in the late 1930s by Pierre Castan in Switzerland and Sylvan Greenlee at the American firm Devoe and Raynolds. Castan filed patents in 1936 covering the reaction of bisphenol A with epichlorohydrin, work that was licensed to Ciba, which began commercial production in the 1940s. Greenlee pursued closely related chemistry in the United States over the same period. Initial applications were dental casting materials and electrical potting compounds, where the low shrinkage and strong adhesion of the cured resin were the attractive properties. Shell and Dow entered large-scale epoxy resin manufacture during the 1950s, driving prices down enough for construction use. Epoxy moved into flooring through industrial demand: factory, aircraft hangar, and food processing floors needed a surface that resisted solvents, acids, and forklift abrasion better than sealed concrete or terrazzo. Contractor-applied industrial epoxy floors were established practice by the 1960s. The consumer garage kit, packaging a pre-measured resin and hardener with decorative vinyl flakes and application tools, is a much later development that took hold in the 1990s and 2000s as home improvement retail expanded. Polyaspartic coatings, based on aspartic ester chemistry commercialized by Bayer around 1990, later joined the category as fast-cure topcoats offering ultraviolet stability that standard bisphenol A epoxies lack, which is why bare epoxy ambers under sunlight and is usually topcoated.