South Hill Mini Storage Main Entrance - Aerial View - Spokane, Washington

South Hill Mini Storage Metal Roof Retrofit – Spokane, WA

by | Mar 29, 2025 | Commercial, Commercial Metal Roofing Systems, Commercial Roof Replacement, Commercial Roof Service, GAF

Spokane Roofing Company®, LLC recently completed a commercial metal roof retrofit project at South Hill Mini Storage in Spokane, WA. We recovered leaky metal roofs with single-ply TPO membrane roofing systems. Retrofitting not only extends the life of a metal roof by up to 20 years, but it is also less expensive than a full roof replacement. A retrofit improves both insulation and moisture resistance on an existing metal roof, as well.

Several of the retrofit projects we have completed have involved converting leaky self-storage unit metal roofs to flute-fills. All metal roofs leak eventually, but leaky storage units do not do the most important thing that they are supposed to do, keeping their contents dry.

Flute-fill insulation and acrylic coatings are great options to address problems with commercial metal roofs. As with every other roofing option, Spokane Roofing Company has the experience and the knowledge to take care of building owners’ concerns. Retrofitting typically involves custom-cutting lightweight EPS (expanded polystyrene) panels and installing them into the flutes or channels in a metal roof. We then put a hard covering board over that and mechanically attaching the roof to wood or metal purlins.

Flute-fill only works on low-slope or flat metal roofs. We work with structural engineers during the permitting process when local governments require a structural analysis. This analysis of the extra roof weight ensures safety and stability.

Ten years ago, Spokane Roofing Company completed a metal roof retrofit at Wasem’s Pharmacy in Clarkston. That roof was at least 40 years old and had begun to develop severe leaks. We removed foam coating, installed underlay, insulation, and TPO roofing membrane.

As the roofing industry has advanced since then, so has flute fill retrofitting. We have done many similar projects during that time. The Wasem’s project was innovative at that time, and the industry has since then adopted flute fill as an acceptable practice. Spokane Roofing does commercial metal roof retrofits almost as often as we do metal roof replacements.

Jeff Sitton, Spokane Roofing Company

Most of our retrofitting projects come from referrals or repeat business, often completing work in phases. Questionable roofers saturate today’s commercial roofing industry. Only a few commercial metal roofers have established themselves over the long term. People call us because we are consistent, and they know that they can count on us to do their metal roof retrofit job right.

Craftsmanship and honesty are two core values at Spokane Roofing Company. These values help to make us the top commercial roofer in the Spokane Metropolitan area. We recognize that there is always room for improvement, and it is my responsibility to steer us away from the status quo. With that in mind, we have undertaken a rigorous review of every service we offer, including commercial metal roof retrofits. Our goal is to make every process more efficient and effective for our customers.

Self-Storage Metal Roof Retrofit Project Major Material List

The two-week, 4,500 square-foot commercial metal roof retrofit project used the following major materials:

  • 60-mil, Single-Ply, TPO Membrane Roofing System, White
  • UltraLight Glass-Mat Roof Board
  • 1.0#PCF EPS Foam Flute Filler.

Convoy Supply Ltd. in Spokane Valley supplied the TPO membrane roofing materials, recover board, and accessories.

Commercial Metal Roof Retrofit Project Photographs

Progression From Prepared Metal Roof Deck To Flute Fill To Recovery Board

Progression From Prepared Metal Roof Deck To Flute Fill To Recovery Board

Work begins with transforming the original metal roof into a new roof deck. Commercial roofers cover exposed metal fasteners and grommets with white mastic. Next, they loosely lay factory-cut EPS foam flute filler panels between the metal roof’s flutes. Then, they install lightweight recovery board to create a flat surface to which they will attach the TPO membrane roofing.

Single-Ply TPO Membrane Installation Underway

Single-Ply TPO Membrane Installation Underway

Having created a flat roofing area, the flat roofers begin to install the 60-mil, Single-Ply, TPO Membrane Roofing System on one side of the roof. They layout rolls of membrane roofing and cut it to length. Next, the roofers fully adhere the membrane roofing to the recovery board. They finish by heat-welding and inspecting the TPO membrane seams, probing them for voids.

Metal Roof TPO Retrofit Project Nearing Completion

Metal Roof TPO Retrofit Project Nearing Completion

Commercial flat roofers install prefabricated TPO accessories to seal all rooftop penetrations. Next, they install any metal flashing or similar metal finish pieces. After a final inspection, photographs, and cleanup, the metal roof retrofit project is complete. South Hill Mini Storage’s new TPO roofing systems carry a 5-year Spokane Roofing Workmanship Warranty.

Is A Commercial Metal Roof Retrofit Right For Your Building?

Does your commercial metal roof leak and interfere with normal business operations, costing you money? Discover whether a commercial metal roof retrofit is right for your building. Call Spokane Roofing Company today at (509) 838-8633 to schedule a free commercial roof inspection and estimate.

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