Portland Metro Area : 503-667-0175503-667-0175 503-667-0175
Seattle Metro Area : 253-589-8999253-589-8999 201-594-0900

McDonald & Wetle has been offering comprehensive flat roofing services, including installation, repair and maintenance, since 1921. We utilize some of the most popular roofing systems and materials, and our expert roofing contractors have the knowledge and experience to help prolong the life of your roof and protect your investment. Regardless of the size or complexity of your roofing project, our full-service team of roofing experts meets the demands of business owners throughout Oregon and Washington from our Portland and Seattle locations. We’ve got you covered with an extensive list of flat roofing options to fulfill any need.

Flat Roof Installation

Illustrations of Building with Flat RoofsFlat roofs include any roof with little to no slope. Many commercial and industrial buildings and medical facilities with wide roof spans commonly have roofs that are flat or nearly flat with a low slope to allow water runoff. Flat roofs are notorious for developing leaks. Roofing systems for buildings with low or no slopes need layers to ensure water resistance, as well as strength and stability. In our 98-year history, we’ve installed nearly every type of roofing system, so we can help you determine which system works best for your roof’s needs based on slope and complexity. We expertly replace existing flat roofs or install flat roofing systems on buildings under construction.

Roofing Options For Flat Roofs

Flat roofs can’t be covered with shingles, shakes or tiles due to blow-off and water pooling. We offer superior built-up, modified bitumen and single-ply (EPDM, PVC or TPO) roofing systems for flat or nearly flat roofs of all kinds.

  • Traditional built-up roof (BUR) systems have been around longer than any other flat roofing system. The time-tested performance of these roofing systems makes them an ideal choice for many commercial and industrial applications. BUR systems are moderately priced due to their simplicity and usually consist of multiple layers of tar and a gravel-surfaced or smooth-coated top layer. Tar may be hot-mopped or cold-applied, and the numerous layers create a durable, water-resistant surface appropriate for flat roofs and most low-slope roofs with a pitch of up to 3/12.
  • Modified bitumen roof systems, also called modified built-up roofing, are similar to BUR systems but are rolled onto the roof surface in sheets instead of mopped on. These sheets include additional polymers for extra protection and extended lifespan and are heated with a blowtorch during installation to provide a good seal. While modified bitumen systems tend to be slightly less expensive, they don’t withstand foot traffic as well. However, they are one of the more environmentally friendly flat roofing options due to their reflective nature, which helps reduce energy costs and keeps your building cooler.
  • Single-ply roof systems include a variety of applications, but each one typically provides reflective properties that help keep your energy costs to a minimum. While each system is similar, they each offer unique properties to fit various conditions. We help you determine which system best suits your specific needs, performance requirements and budget. The three most commonly used types of single-ply roofing systems include:
    • EPDM (Ethylene Propylene Diene Monomer), a synthetic rubber or artificial elastomer product that’s glued to the surface beneath it. These membranes are lightweight and flexible and have a high wind rating, making them ideal for roofs with limited load-bearing capacities or tall buildings in high-wind areas. Single-ply EPDM systems have a uniform appearance that makes them more aesthetically pleasing than other options, and the synthesized ingredients resist weathering, ozone and ultraviolet light.
    • PVC (Poly Vinyl Chloride), a vinyl-based membrane that can be fully adhered or mechanically attached. Considered a mid-range flat roofing product, PVC membranes offer pliable yet durable sheets with excellent weathering characteristics and resist harsh chemicals and pollutants.
    • TPO (Thermoplastic Polyolefin), a vinyl-based membrane developed to compete with BUR systems. These membranes are highly reflective, which makes them an energy-efficient option. TPO can be fully adhered or mechanically attached and offers a strong option that requires minimal maintenance.

Flat Roofing Experts In Portland, Oregon

No matter your flat roofing needs, our experienced roofing professionals at McDonald & Wetle can make your next project a hassle-free experience. Our family-owned professional roofing company specializes in all types of flat roofing systems. We’ll work with you to devise a customized system that perfectly fits your project needs. In Seattle, Washington, call 253-589-8999 and in Portland, Oregon, call 503-667-0175 for a quote on your flat roof installation today.

Contact Us
McDonald & Wetle

Portland Metro Area

2020 NE 194th Avenue, Portland
OR 97230, USA
Phone: 503-667-0175 503-667-0175
Hours of Operation:
Monday-Friday 8am to 4pm

Seattle Metro Area

9420 39th Avenue, Lakewood
WA 98499, USA
Phone: 253-589-8999 253-589-8999
Hours of Operation:
Monday-Friday 8am to 4pm

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