Built-Up Roofing (BUR) in Toms River, NJ
Built-up roofing is the original commercial roofing technology, with a track record spanning more than a century. Before single-ply membranes existed, built-up roofing (commonly called BUR or "tar and gravel") was the standard for flat and low-slope commercial buildings across the United States. Today, BUR remains a technically sound, durable specification for certain building types and applications where its unique characteristics — multi-ply redundancy, mass, and proven longevity — make it the preferred choice. Toms River Roofing Contractor installs and replaces built-up roofing systems for commercial properties throughout Ocean County, NJ.
What Is Built-Up Roofing?
Built-up roofing consists of multiple alternating plies of reinforcing felt and hot asphalt (or cold-applied adhesive), topped with a flood coat of asphalt and aggregate surfacing — typically river-washed gravel or crushed slag. Each ply contributes to the overall waterproofing assembly, creating a redundant, monolithic system with no seams in the conventional sense.
The essential components of a BUR system are:
Reinforcing Felts — Fiberglass felts are the current standard, replacing the organic felt products that were common in older systems. Fiberglass felts are dimensionally stable, rot-resistant, and provide the structural reinforcement that holds the asphalt layers together. Typically two to four plies are applied, depending on the system specification and performance requirements.
Bitumen — Oxidized asphalt (Type I, II, III, or IV) is heated in a kettle to the appropriate application temperature and mopped or poured over each felt ply. The asphalt fills the voids in the felt and bonds plies together into a continuous waterproofing mass.
Surfacing — A flood coat of asphalt is applied over the top felt ply, into which aggregate — typically No. 4 washed gravel at 400 lb/square — is immediately embedded. The aggregate protects the asphalt from UV degradation, provides fire resistance, adds thermal mass that moderates temperature cycling, and protects the membrane from physical abuse.
Base Sheet — A mechanically fastened or nailed base sheet is typically installed first, providing the initial substrate layer and primary attachment to the structural deck.
Why BUR Still Makes Sense for Some Buildings
Genuine Multi-Ply Redundancy
A 3-ply or 4-ply BUR system has no single point of failure. Water that penetrates the cap sheet must work through multiple additional layers before reaching the structural deck. This redundancy is fundamentally different from a single-ply membrane, where a seam failure or puncture produces a direct leak path. For critical facilities — hospitals, data centers, pharmaceutical manufacturing, food processing — this redundancy has real value.
Thermal Mass Benefits
The aggregate surfacing and multiple asphalt plies give BUR systems significant thermal mass. The roof absorbs heat during the day and releases it slowly, moderating the temperature swings that create thermal stress in single-ply membranes. In Ocean County's climate, where temperature differentials between summer and winter extremes can exceed 100°F, this mass reduces the cyclic stress on the membrane assembly.
Proven Longevity on Older Buildings
Many Ocean County commercial buildings constructed in the 1960s through 1990s have BUR systems approaching or exceeding 30 years of service. The original systems outlasted their design life because of BUR's inherent durability and, in many cases, because the aggregate surfacing has continued to protect the underlying asphalt from UV degradation. Replacing like for like preserves the known performance characteristics of the assembly.
Compatibility with Existing BUR Buildings
Re-roofing an existing BUR building with BUR avoids compatibility concerns that can arise when converting to a different system type. The same materials, the same detailing approaches, and the same maintenance protocols apply.
BUR Installation Process
Pre-Installation Inspection and Deck Preparation
Before installation begins, the structural deck is inspected for integrity after the existing roofing is removed. BUR systems add meaningful dead load — typically 5–8 psf depending on the aggregate type and application rate — and the structural deck must be verified to have adequate capacity. Wood or lightweight concrete deck substrates require specific preparation before BUR application.
Base Sheet Installation
A fiberglass or polyester base sheet is nailed or mechanically fastened to the structural deck at the required fastening density. This sheet provides the primary attachment to the structure and serves as the substrate for the mopped plies above.
Ply Application
Each subsequent ply is embedded in hot asphalt mopped at the specified application temperature and rate. Our crews work systematically from the low point of the roof toward the high point to ensure proper drainage slope is maintained in the ply application direction. Inter-ply asphalt application temperatures are monitored to ensure adequate bonding without overheating the felt.
Flood Coat and Aggregate Application
After the final ply is applied, a flood coat of asphalt is mopped over the entire surface at a rate of approximately 60 lb/square. Aggregate is immediately embedded into the flood coat before it cools. Application rates and aggregate gradation are verified against the manufacturer's specification for the system being installed.
Flashing Installation
Perimeter and penetration flashings are installed using modified bitumen cap sheet material, fabric-reinforced base flashings, and sealants appropriate for the specific detail. BUR flashing methodology is inherently more labor-intensive than single-ply systems — each detail is built up with multiple layers, which is why BUR details can be both more durable and more expensive than equivalent single-ply details.
BUR Maintenance and Repair
BUR systems are maintainable and repairable throughout their service life. Common maintenance items include:
Aggregate Redistribution or Replacement — Wind and drainage can cause aggregate migration away from certain areas, leaving bare asphalt exposed to UV. Redistributing or adding aggregate to thin areas extends the membrane's UV protection.
Blister Repair — Blisters form when moisture trapped during installation or in damp insulation expands under heat, creating pockets between plies. Minor blisters can be controlled; larger blisters may require cutting, drying, and resealing.
Flashing Re-sealing — Perimeter and penetration flashings are the most maintenance-sensitive areas of any BUR system. Regular inspection and prompt re-sealing of opening flashings prevents water infiltration.
Coating Application — Reflective aluminum or fibered asphalt coatings can be applied over existing BUR surfaces to improve solar reflectance, seal minor surface oxidation, and extend service life.
New Jersey Code Compliance for BUR
Built-up roofing assemblies must be listed and labeled for the required fire rating. Most commercial BUR assemblies qualify for Class A fire ratings when specified with the appropriate aggregate and installed per the manufacturer's tested assembly. New Jersey's building code requires Class A roofing for most commercial occupancies. We specify only code-compliant BUR assemblies.
Wind uplift design for BUR systems must account for the attachment method of the base sheet and the number of fasteners or nails per square. Our specifications include formal wind uplift calculations for each project.
When to Consider BUR vs. Modern Single-Ply
BUR is worth considering when:
- You are replacing an existing BUR system and want continuity
- The building requires maximum leak redundancy due to critical operations below the roof
- The structural deck can accommodate the additional dead load
- Budget allows for the higher labor cost of BUR compared to single-ply
- Long-term maintenance will be managed by experienced commercial roofing contractors
Single-ply systems (TPO, EPDM, PVC) are often the better choice when:
- Energy efficiency is a top priority (white TPO or PVC offer superior solar reflectance)
- The structure has limited dead load capacity
- Faster installation and lower installed cost are driving factors
- A manufacturer NDL warranty with modern warranty management is required
We discuss both options honestly with every client and provide proposals for the system best suited to your building, budget, and performance requirements.
Call 732-831-7434 to schedule a BUR assessment for your Ocean County commercial property.