Knapp & Schlappi Lumber Company is a supplier of building materials and hardware products. The company offers plumbing, electrical, lighting, cleaning, office and paint supplies. It provides composite siding, straps, truss hangers, rebar and pins. Knapp & Schlappi Lumber Company offers several types of lumber products, including stringers, panels and boards. The company s cleaning supplies include soaps, dish mops, glass cleaners, floor waxes, brooms, brushes, furniture polishes and mop buckets. It also provides hand and power tools. The company provides Therma-Tru and Stanley brand doors and windows for interior and exterior applications. Its office supplies include highlighters, tapes, black ink cartridges, glue sticks and labels. Knapp & Schlappi Lumber Company is located in Penn Yan, N.Y.