These flashings are installed around objects on the flat surface of flashing a roof. These flashings are made of felts, asphalt, flashing cement, lead and other metals. Surfacing The third part of a BUR membrane is surfacing. There are three types of surfacing. One type is aggregate.
Aggregate means gravel, crushed stone, slag or marble chips.
The other two types are called cap sheets and smooth-surfaced Aggregate Aggregate surfacing is gravel, crushed stone or marble chips. This material is set in a flood coat of bitumen. Cap Sheets Cap sheets are felts coated with asphalt. When they are made at a factory, they are surfaced with mineral granules. They are usually set in hot bitumen as the final surfacing.