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Case Studies

GacoFlex S20 Silicone Over Foam Barrel Roof Restoration – Barnes and Noble on the Santa Monica Promenade (CA)

Case History GacoFlex S20 Acrylic Flat Barrel Foam Restored Barnes and Noble CA Photo1


Barnes and Noble is located in an old landmark building at 1201 3rd Street in Santa Monica. The building’s existing 20,000 square foot roof is both barrel and flat with an acrylic coating over a spray foam roof system. The spray foam roof was absorbing moisture and required repair. Barnes and Noble turned to their Roof Consultant, Norm Francis of Benchmark, Inc., for a recommendation.


Norm Francis was familiar with Gaco Western products and recommended first repairing the spray foam roof, and then installing the GacoFlex S20 Roof Coating System because it forms a monolithic system that fully adheres to any shape or substrate to provide a seamless weather-tight seal. GacoFlex S2000 Solvent-Free 100% Silicone Roof Coating features FM Approval, has a highly reflective, glossy finish that can reduce cooling costs, and will endure permanent ponding water without softening. While all GacoFlex coatings carry a 50 Year Limited Material Warranty, Gaco Western and Permanent Roof offered a 20 Year Labor and Material Warranty on the coating project, ensuring that Barnes and Noble could be confident they had the long-lasting protection they needed.

Unique Characteristics: 

The existing spray foam roof required various repairs which included removing and replacing the moisture-laden foam with 3 lb/sq. inch 2-stage repair kits. Moisture travels in spray foam, and if any wet spray foam was not removed and replaced it would cause the Silicone Coating to blister. To help ensure that all moisture was successfully removed from the spray foam, Permanent Roof removed and replaced more foam around the water-damaged area than may appear necessary to the untrained observer. A Gaco Field Service Technician was on hand several times to inspect the repairs and perform test cuts which helped Permanent Roof ensure they kept the roof a consistent thickness.

Installing the GacoFlex S2000 Solvent-Free 100% Silicone over 2000 Square Feet of 6:12 pitch/26 degrees roof was a challenging job. The roof was slippery and, at the specified application rate of 2.5 gallons per 100 square feet, the coating could possibly run, streak and blob which would have caused inconsistent thickness and the chance of too little coating in some areas of the roof. Instead, Permanent Roof opted to install two separate, thinner layers to achieve the specified 38 dry mils, making it easier to keep the thickness consistent everywhere.


Various repairs were made to the existing spray foam roof by removing and replacing the moisture-laden foam with 3 lbs/sq. inch 2-stage repair kits. After repairs were completed, the roof was power washed to remove dirt and debris, allowed to dry thoroughly and then primed with GacoFlex E5320 2-Part Epoxy Primer. Next, roof details were sealed using GacoFlex SF2000 SeamSeal and then GacoFlex S2000 was applied in 2 layers to achieve a total of 38 dry mils.

“This was a challenging job. Due to the air conditioning units and mechanical platforms, attention to detail was critical. However, once the E5320 Primer was applied, and the roof was detailed using SF2000 SeamSeal where applicable, the GacoFlex S20 Silicone Coating went down nicely and the roof turned out beautiful,” according to one of the Permanent Roof applicators.

This roof was inspected by Benchmark, Inc., an independent roof consulting company. Their representative, Norm Francis said, “The roof was installed professionally and can be used as a reference anytime.” Permanent Roof added, “We’re grateful to Norm for being so available and supportive throughout the process.”



Location: Santa Monica, CA
Specification: GacoFlex S20 Roof Coating System
Product Type: Barrel Roof over Spray Foam Restoration
Contractor: Permanent Roof
Problem Solved: Existing spray foam roof was absorbing moisture.
Customer: Barnes and Noble; Benchmark, Inc. (Roof Consultant)