TW Perry - Gaithersburg is one of the leading building materials suppliers in the mid-Atlantic, serving the Washington, DC and Baltimore areas and outlying suburbs. We supply lumber, building materials, doors and windows, hardware, decking and railing products, paint, and power tools. We also offer a wide selection of millwork products, including more than 250 in-stock moulding profiles as well as special order products. We credit our success to establishing loyal customers in the Gaithersburg area who understand the added value and partnership that our services and products bring their business, as well as our enthusiastic, customer service-focused team members.