Liquid-Applied Roofing & Waterproofing Systems

How a liquid-applied system works

The roof is cleaned and prepared, damaged areas and details are repaired, and the system is applied in coats over the prepared surface. As it cures, it forms one seamless, waterproof layer across the whole roof that also wraps up and around the details. That finished layer is the part that faces the sun and the rain, so the roof under it does not have to. The products, the number of coats, and any reinforcement depend on the roof and the manufacturer system we specify.

Where it fits

• Commercial flat and low-slope roofs: plazas, offices, warehouses, and association buildings
• Roofs with a lot of penetrations, curbs, and rooftop equipment
• Waterproofing details that are hard to seal with sheet materials

It can go over concrete

A liquid-applied system is not only for membrane roofs. It can also be applied directly over a concrete roof deck once the surface is cleaned and prepared. The coats bond to the concrete and wrap up the curbs, walls, and equipment supports the same way they do on any other roof.

Project: St. Regis, Turks and Caicos

RTI Roofing applied a liquid-applied system over the concrete roof surface of a building at the St. Regis in Turks and Caicos. It was RTI's first building at this property. Work on a second building is scheduled to start in January 2027. The photos and videos on this page are from that job.

Restore before you replace

When an existing low-slope roof is still sound underneath, a liquid-applied system can sometimes go over it instead of a full tear-off. That can mean less demolition, less debris, and less disruption for the people using the building. It is not right for every roof. Wet insulation, a failing deck, or water that stands long after a storm all change the answer, and we will tell you when a coating is not the fix.

Backed by GAF certification

RTI Roofing is a 2026 GAF Certified™ Commercial Contractor and a 2026 GAF Certified™ Roofing Contractor. GAF certification lets RTI offer eligible customers enhanced manufacturer warranty options that not every roofing contractor can provide. On qualified commercial projects, those include the GAF System Pledge™ Roof Guarantee and the GAF Integrated System Limited Warranty. Which options apply depends on the project and the system installed.

What the visit covers

• The existing roof surface, seams, and any soft or wet areas
• Drains, scuppers, and the path water actually takes
• Curbs, penetrations, and edges around rooftop equipment
• Whether the roof is a candidate for a liquid-applied system, or needs repair or replacement first