No Trim 21 is a two component, light density, one-to-one-by-volume spray-applied polyurethane foam. A single pass at 5” of No Trim 21, in a typical 2×6 wall cavity, will achieve an R-21 without trimming of excess material. To produce No Trim 21 requires the use of an “A” component (ISO) and a blended “B” component (RESIN), which contains ZERO ozone-depleting blowing agents, catalysts, polyols, and fire-retarding materials. No Trim 21 is an insulation system designed for use in residential applications. Use it in lieu of more traditional forms of insulating materials such as fiberglass, cellulose, or other loose-fill products. Typical areas where spray polyurethane foam is applied are exterior walls, interior walls, vented attics, unvented attic assemblies between floors, and ceilings.