TPO roofing systems are a great choice for flat roof applications and are easy and affordable to maintain.
Standing Seam Metal Roof systems are the fastest growing roof type because of their beauty and strength.
Roof coatings can be great temporary systems and when installed correctly, can be lifetime systems.
Asphalt shingles roof systems are the most common roof systems still. They too are evolving with higher performing features and options, however.
The most common asphalt based flat roof systems are built up roofs made of a modified bitumen or modified asphalt.