Hot-Applied Asphalt Waterproofing/Roofing
This information reflects our best understanding of product composition in 2021.
Hot-applied asphalt waterproofing is made from a variable combination of components that includes a primer, asphalt modified with rubber, a polyester sheet, and a protection course. Typically, hot-applied asphalt waterproofing systems begin with a...
Hot-applied asphalt waterproofing is made from a variable combination of components that includes a primer, asphalt modified with rubber, a polyester sheet, and a protection course. Typically, hot-applied asphalt waterproofing systems begin with a primer, also known as a "surface conditioner," directly on top of a concrete substrate. This primer creates greater adhesion with the hot-applied modified asphalt that is applied next. The asphalt material is sold at room temperature in solid bricks or disks that are heated in a kettle at the job site until melted to a specific temperature. The hot liquid asphalt is then applied to the roofing substrate (post-primer) and forms a seamless monolithic membrane that seals the roof. Additionally, a reinforcment sheet, commonly polyester, is placed between two layers of hot-applied asphalt to improve properties of the system including tear resistance and overall material strength. Lastly, a protection course (bitumen sheet), is added in order to absorb shock and to support backfilling at a later time. Depending on the roof design, stone or other layers can be added to form a built-up roof, or the asphalt layer could be the foundation for a living roof of plants. Post-consumer crumb rubber is used in the membrane component or protection course for some products. This CP describes a hot-applied asphalt waterproofing or roofing system and includes multiple components that are commonly used with the waterproofing membrane.