G.F. Sprague & Co. Inc. is Wayland Ma's replacement window contractor. Whether you have aluminum windows, or vinyl windows, we have the replacement window option for you. All of our work is backed up with a 40 year workmanship guarantee. So you have confidence with GF Sprague with all your work for replacement windows. G.F. Sprague has actually been around considering that 1969 and has over 10,000 pleased customers.