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Case Studies

CalPortland Dome Silicone Roof Coating Project (OR)

Location: Portland, OR
Specification: Master Spec - 07 01 50.61 / RC-S42-34-20 / GacoFlex S42 for Re-Coat
Contractor: Long Painting

Not every roofing project involves a traditional structure. Some projects include buildings with unusual shapes, such as rounded domes. In the case of the CalPortland dome, a creative solution was needed to preserve the dome’s roof. Read on to learn how a Gaco roofing solution helped. 

What problem did Gaco help solve with a silicone coating?

The CalPortland dome was in need of maintenance. The building owner was looking for a cost-effective, eco-friendly roofing system that would work with the building’s unusual shape. CalPortland is using GacoFlex S4222 – GRAY to repair their roof and keep it in great condition.


What Gaco silicone coating solutions were used?

The inflatable dome has a Hypalon membrane previously coated with an unknown product. A test patch of silicone roof coating was installed to check adhesion and aesthetics. GacoFlex S4222 – GRAY silicone coating was chosen to “match” the existing gray and re-cover the roof. 

GacoFlex S4222 – GRAY was applied in two coats with a power roller at 20 mils Wet Film Thickness (WFT) per coat. Spray application was not an option due to wind, exposure, and access. A Graco King 60 air assisted pump was used to supply the silicone to the power roller.  Since pressure was not being built as would be needed to spray, the silicone was pumped at a fairly low pressure.  Air driven-mixers were used to properly mix the material inside the drums.

Telescoping lifts and rappelling tactics were used to install the silicone roof coating. 65 ft (20 m) and 85 ft (26 m) boom lifts were used, but due to the diameter of the dome, the 85 ft (26 m) boom did not have the horizontal or vertical reach to ascend to the top. More creativity was needed so a secure cable system was set up at the top with ropes and harnesses, with lanyards hanging off the cable line. This was the only way to coat the top 12 ft (4 m) if you sliced through the side view of the dome. GacoPatch was applied to the bottom edge termination and dome/building interface to complete the coating project.


What made this silicone roofing solution an especially good match for the area?

Oregon—along with Gaco, Firestone, and Holcim—is green-focused. It was important to go with a more eco-friendly option like a silicone roof coating. Graffiti is also a problem in the area, and GacoFlex S4222 – GRAY silicone provides excellent adhesion resistance to non-silicone paints/coatings.


What made this solution especially suitable for CalPortland?

Long Painting was selected to install the Gaco S42 series silicone on the project as a highly respected and experienced coatings contractor in the NW. The GacoFlex S4222 – GRAY was selected after serious consideration of other materials. After evaluating a test patch of silicone roof coating prior to complete application, the team found that GacoFlex S4222 surpassed adhesion requirements and met the additional constraint of being a good fit for the existing aesthetic. 


How did Gaco help CalPortland reduce costs and risk? 

The dome roof was in need of maintenance. Instead of tearing down the structure and building a new one, which would have been costly, Gaco was able to re-cover the dome with our silicone roof coating system. 


What was interesting about this silicone roofing project?

The CalPortland dome is an inflatable dome with a Hypalon membrane that houses powder needed for the making of pre-mix concrete. The shape of the dome (74 ft (23 m) high and 140 ft (43 m) circumference) required telescoping lifts and rappelling tactics. There was also an Osprey nest above the catwalk that could not be disturbed until the Osprey offspring left the nest in mid-summer. Activity had to be monitored to not adversely affect the Osprey.


What key points about the CalPortland project could help Gaco and our Customers win more business? 

This project called for an extreme, difficult installation involving lifts, telescoping lifts, open exposure, and careful work around an Osprey nest. It showcases how Gaco is a proven resource for roof coating solutions. We can help anywhere, anytime, and with any installation requirements.


What about the CalPortland project is the Area Manager most proud of?

Since this was such a unique project, installing the silicone coating required great teamwork between all parties—manufacturer, owner, and contractor. Teamwork makes the DREAM work!

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How can Gaco help your business?

The CalPortland project has shown Gaco can handle a wide range of projects—including those involving nontraditional buildings. To learn more about your silicone roofing solutions and find the right match for your business, please contact your local Area Manager.