High-Visibility Retail Center Gets a High-Quality App Modified Bitumen Roofing

The SoDo retail center in Seattle is situated within the city’s central business district and is conveniently located across the street from Starbucks Global Headquarters, the world’s largest coffeehouse chain. Additionally, the property is just a few blocks from T-Mobile Park and Lumen Field, home to the Seattle Mariners, Seattle Seahawks, and Seattle Sounders, attracting millions of visitors for sporting events and concerts.

The property’s prime location, just over a mile south of downtown Seattle, offers direct access to major highways and the city’s vibrant business district, which hosts leading tech giants such as Amazon, Google, Facebook, and Salesforce.

When it came time to remodel the center and install a new roof, ensuring quality and reliability was paramount. For this reason, Northwest Roof Service Inc. was chosen to handle the project.

Since 1987, Northwest Roof Service Inc. has been delivering exceptional roofing services for industrial, commercial, and residential properties across Bellevue, Seattle, Tacoma, and neighboring areas. Whether clients require roof repairs for their homes or commercial roofing solutions for their businesses, Northwest Roof Service Inc. offers outstanding service at competitive prices. With extensive experience and in-depth industry knowledge, they ensure every project is completed in compliance with manufacturers’ specifications and building code standards.

Northwest Roof Service specializes in a wide range of roofing solutions, including new construction, replacements, and repairs, with expertise in composition, wood shake, tile, metal, and torch-down roofing materials.

When the owner of the SoDo retail center approached Northwest Roof Service Inc. for a new roof, they initially requested a single-ply thermoplastic polyolefin (TPO) system. However, after Northwest Roof Service showcased the durability and reliability of an APP-modified bitumen roof system (using Atactic Polypropylene (APP) modified asphalt), they secured the project.

For this project, Northwest Roof Service Inc., a Quantum Contractor, teamed up with Polyglass USA, known for their high-quality products and services. With over 30 years of experience, Polyglass USA is an ISO-certified industry leader in manufacturing modified bitumen membranes and roof coatings for both low- and steep-slope applications. Utilizing the most advanced manufacturing processes in the roofing industry, Polyglass operates six cutting-edge facilities—five in North America and one in Italy.

Northwest Roof Service first applied Polyglass USA’s G2 Base, a fiberglass mat coated with an oxidized asphalt blend that provides enhanced weathering and aging characteristics.

Then, Polyflex G, an APP (plastomeric) granulated cap sheet for low-slope roofing designed for heat-welded applications, was added. This product incorporates a superior non-woven polyester mat that provides flexibility, dimensional stability, and exceptional tear and puncture resistance. Plus, the proprietary plastomeric compound and durable construction provide long-term weathering performance.

Together, these products not only met the complicated drainage needs for the roofs at the site, but they also allowed the Northwest Roof Service team to expertly handle the fine detail work around the massive skylights on the buildings’ roofs.

“The reliability of Polyglass products is unmatched in the industry,” shared Travis Anonson of Northwest Roof Service Inc. “At times, I needed guidance from the Polyglass team and immediately got a response, which was imperative to accomplishing this roof for the customer.”

By the Numbers

Location

2416, 2408, 2414, and 2418 1st Ave. South Seattle, Washington

Size

31,000 square feet

Challenges

  • Complicated drainage needs for multiple flat-roof retail buildings.
  • Extensive detail work is required around massive skylights on the roofs.

Product Spotlight

Polyglass G2 Base

Polyglass G2 Base is a premium fiberglass mat coated with an oxidized asphalt blend, offering enhanced weathering and aging properties. This innovative product is engineered for use as a base sheet in built-up and modified roofing systems, providing exceptional tear and pull-through resistance. With its robust construction, Polyglass G2 Base ensures reliable protection and long-term performance, even in the harshest weather conditions. Designed to meet or exceed ASTM D4601 standards, it is a trusted solution for a variety of roofing applications.

Ideal for mechanically attached systems, Polyglass G2 Base is intended to be covered with Polyglass torch interply or cap sheets. It may also be used in hot-mopped or cold-applied systems, depending on specific project requirements. The product’s superior pliability and dimensional stability make it easy to install, as it resists wrinkles and lays flat for a smooth application. With consistent thickness on both sides, Polyglass G2 Base delivers uniform performance, making it an excellent choice for high-quality roofing systems that demand durability and ease of installation.

Polyflex G

Polyflex G is an APP (plastomeric) granulated cap sheet designed for low-slope roofing, specifically created for heat-welded applications. This high-performance product features a non-woven polyester reinforcement that offers excellent flexibility, dimensional stability, and outstanding resistance to tears and punctures. The advanced APP (plastomeric) compound and robust construction ensure exceptional long-term weathering performance. The top surface is granulated for added protection, while the bottom is coated with a factory-applied burn-off film.

Polyflex G also incorporates Polyglass’ patented FASTLap® technology, which eliminates granules at the end laps, simplifying installation and ensuring a faster, more efficient application process. FASTLap provides a stronger, more reliable watertight seal for enhanced durability.

Details and flashings can be installed using torch-applied techniques, but it is important to avoid adhering to hot asphalt or cold adhesives. When combined with Polyflex base or interply sheets or other approved Polyglass base sheets, Polyflex G forms part of a warranted multi-ply system, offering comprehensive protection and superior performance in low-slope roofing applications.

Lynnwood Senior Living

Project Overview:

Roofing Contractor 3-D Roof System installs Polyglass’ Vegetative Roof atop the SHAG (Senior Housing Assistance Group) Lynnwood, Wash. property. Backed by a 30-year warranty, the three-ply modified bitumen system chosen provides the critical waterproofing needed for a vegetative roof assembly. At 500-mils thick, the system adds layers of defense for the roof and enables long-term performance. In comparison, singly ply membranes typically have a 60 mils total thickness.

Products include two layers of Polyglass’ Polyflex® Smooth APP (Atactic Polypropylene) modified bitumen membrane for the base and interply sheets. For the final layer, Polyflex® G White APP cap sheet was installed to provide resistance to punctures, tears, abrasion, foot traffic and the elements. Elastoflex SA V—a high performing self-adhered membrane featuring Polyglass’ ADESO® Technology was used for the flashing details.

Challenges:

3-D Roof Systems began the roof installation in October 2016, which according to the Seattle Times had record breaking rainfall.  But 3-D Roof Systems was prepared for the inclement weather. The team used a system of inflatable tenting adapted for use on the roof to work around the weather.  As they completed sections of the roof, the tent was moved to new areas that needed to be worked on.

Read more!

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Van Asselt Community Center

The 9,800-square-foot addition project called for a self-adhered, modified bitumen roofing material that the city of Seattle had often used in the past. However, the specified material was quite costly, leading everyone to search for an alternative.

After considering a number of options, the project’s roofing contractor, SQI Inc., decided on PolyKool®, a highly reflective, modified bitumen roofing membrane that is part of Polyglass’ KOOL ROOF SOLUTIONS. PolyKool is an APP-based, modified bitumen membrane that utilizes Polyglass’ patented ADESO® Dual-Compound Self-Adhered Technology.

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Newcastle Library

The building has several eco-friendly features including a green roof. A garden roof was installed over a Polyglass SBS roof system which included 1/2″ Densdeck prime that was mechanically attached, followed by Elastobase V torched vapor retarder. Then Polyisocyanurate insulation was mechanically attached with 1/4″ Densdeck prime set in adhesive. The system was finished with Elastoflex SA V base sheet, a ply of Elastobase V torched and capped with Elastoflex S6 G FR in white.

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