The Redundant Advantage
Why Built-Up Roofing is Making a Western Comeback
by James Yundt, President & GM, Roofmaster Products Company
(Editor’s Note: James Yundt is the president and GM of Roofmaster® Products Company and has celebrated nearly 20 years of service with the third-generation company. He has worked in virtually every department at Roofmaster, and continues to oversee all areas of the company and lends his knowledge and industry expertise to sales, marketing, and manufacturing.)
In the landscape of Western commercial roofing, where the scorching sun of the Mojave meets the coastal moisture of the Pacific Northwest, the industry is witnessing a notable return to tradition. Built-Up Roofing (BUR), colloquially known as hot mop or tar and gravel, is experiencing a resurgence. While single-ply membranes have dominated the market for years due to their speed of installation, savvy facility managers and contractors are rediscovering that when it comes to sheer longevity and redundancy, the old-school hot roof is often the superior solution.
The Power of Multi-Ply Redundancy
The primary appeal of BUR lies in its architecture. Unlike single-ply systems that rely on a single membrane, often as thin as 45 or 60 mils, to protect the building, a built-up roof is a composite of multiple layers. By alternating plies of reinforcing felt or fiberglass with coats of hot-applied bitumen, the system creates a thick, monolithic shield.
This belt and suspenders approach means that if the top layer is punctured by a dropped tool or wind-blown debris, the underlying plies continue to provide a watertight seal. In an era where extreme weather events are becoming more frequent, this redundancy offers a level of peace of mind that thin-film alternatives struggle to match.
Longevity Through Thermal Mass
In the West, thermal shock is a roof’s greatest enemy. Thermal shock is the rapid expansion and contraction of roofing materials caused by drastic temperature swings. The heavy surfacing of a BUR system, typically gravel or mineral-capped sheets, provides excellent UV protection and thermal mass. A properly maintained four-ply or five-ply hot roof can easily exceed a 30-year lifespan, often outlasting single-ply competitors by a decade or more.
Navigating Permits & Site Logistics
The resurgence of hot roofing brings modern challenges, specifically regarding compliance and safety. Because the process involves heating kettles and open bitumen, local municipalities in the Western states have tightened permitting requirements.
- Permit Procurement: most Western jurisdictions require specific hot work permits in addition to standard building permits. These often necessitate a pre-job inspection of the kettle area and fire safety equipment.
- Site Permissions: beyond the city hall, site-specific permissions are critical. Coordination with building occupants regarding fume mitigation and kettle placement is essential to avoid job site shutdowns.
- Safety Compliance: in states like California, Cal/OSHA requirements for hot-applied systems are stringent. Ensuring all crew members are certified for hot-pipe operations isn’t just a legal hurdle, it’s a hallmark of a professional outfit.
For the Western contractor, the return to BUR represents a shift back toward craftsmanship and durability. It is a time-tested system that, when installed with modern safety standards and proper permitting, remains the gold standard for high-traffic, high-value commercial assets.
