non-metallic building materials, namely plastic pipes for building purposes; mobile buildings; mobile prefabricated and modular tool sheds and greenhouses; fencing elements and parts thereof namely, gates and slabs; fencing panels; railing for balconies and stairs; balustrades; door and window frames; door panels and wing windows; doors for houses; garage doors; garden doors; basement windows; window sills; stair elements, namely, treads, risers, and hand rails; attic stairs; fire protection doors, window shutters, venetian blinds, and window blinds; panels for ceilings, doors, and roofing; [sheet rock] * wallboard * panels; stair treads; manhole covers; plastic and wood crates for building purposes; gullies; gutter grids; wood moldings; mobile swimming pools; nonmetallic monuments; stones for fountains, springs, and wells; non-metallic spring troughs and heads of wells; asphalt, pitch and bitumen; worked wood for building purposes; non-metallic flooring elements, namely, parquets and flooring elements, namely, panels, underlayments for boats; non-metallic palisades, stones for retaining walls; concrete tiles, clay and ceramic tiles; clinkers; bricks; natural stone tiles; cement; grout; plaster; and tar paper