Upon removal of this home's old, drafty door, a previously unknown rotten sill was discovered. Fortunately for these homeowners, Windura's FGIA InstallationMasters trained expert employees (never subcontractors!) solved the problem without a hitch! As is typical with a professional Windura installation, the opening was leveled, reinforced and protected so that the gorgeous new Marvin Elevate door will operate efficiently and smoothly for many years to come!