We are replacing a lot of torch down flat roofs with TPO. TPO is usually white or grey and is a much better roof than torch down. It is installed to the roof deck with screws and plates and then the overlapping seams are heat welded. The result is a clean, seamless and long-lasting flat roof. TPO is installed on both residential and commercial flat roof applications. In this case it was an apartment building in Renton. The pictures I took are during the roof installation because I wanted you to see how the product goes down.