Logic Lumber | Construction Materials Lethbridge | Home Logic Lumber (Leth) Ltd,Building Supplier,Building Supplies,Construction Materials,Doors,Drywall,Hardware,Lumber,Metal Siding,Plywood,Windows,Insulation Contractor,Decking,Vinyl Siding,Metal Buildings,Complete Line of Building Supplies,Helping Build Southern Alberta Since 1984,Canadian Home Builders' Association Logic Lumber offers a vast lumberyard and other building materials and hardware for clients in Southern Alberta and parts of Saskatchewan.