Inverted roof with chimney and skylight and gravel top
Commercial Flat Roofing

Built-Up Roofing (BUR) Systems

Time-tested protection with over 100 years of proven performance. Built-Up Roofing delivers unmatched durability through multiple layers of bitumen and reinforcing fabrics, finished with a protective gravel surface.

100+
Years of Proven History
30
Year Maximum Lifespan
4+
Protective Layers
How It Works

What Is Built-Up Roofing?

Built-Up Roofing (BUR) is one of the oldest and most reliable commercial roofing systems available. It's constructed by alternating layers of bitumen (asphalt) with reinforcing fabric sheets, creating a thick, durable, waterproof membrane. The top is typically finished with gravel, slag, or a mineral cap sheet for UV protection and fire resistance.

Flat roof with pebbles

How BUR Systems Are Built

1

Base Sheet Installation

A reinforced base sheet is mechanically fastened or adhered to the roof deck to create a solid foundation.

2

Alternating Layers

Multiple layers of hot bitumen (asphalt) are applied alternated with reinforcing ply sheets. Each layer adds strength and waterproofing.

3

Surface Flood Coat

A top pour of hot bitumen seals the entire system, creating a monolithic waterproof barrier across the roof.

4

Gravel or Mineral Surface

The final protective layer of gravel or mineral cap sheet provides UV protection, fire resistance, and impact durability.

Why Choose BUR

Benefits of Built-Up Roofing

Proven Longevity

With over 100 years of proven performance, BUR systems have stood the test of time. A properly installed BUR roof can last 20-30 years with regular maintenance.

Superior Waterproofing

Multiple layers of bitumen create a seamless, monolithic waterproof membrane. The flood coat ensures there are no seams for water to penetrate, providing unmatched leak protection.

Fire Resistant

The gravel or mineral surface provides excellent fire resistance, often achieving Class A fire ratings — the highest level available for roofing materials.

Foot Traffic Ready

The protective gravel surface can withstand heavy foot traffic from maintenance workers, HVAC technicians, and other rooftop access without compromising the roof's integrity.

Impact Resistant

The layered construction and gravel surfacing absorb impacts from hail, falling debris, and rooftop activity better than most single-ply membrane systems.

Easy to Repair

When damage does occur, BUR systems can be easily patched and repaired by adding additional layers of bitumen and fabric without requiring a full roof replacement.

Best Applications

Where BUR Excels

Built-Up Roofing is the go-to choice for specific commercial applications where durability and long-term performance are paramount.

Large Commercial Buildings

Office buildings, retail centers, and mixed-use developments benefit from BUR's proven waterproofing and long service life. The system's weight also helps with wind uplift resistance on large roof expanses.

Industrial Facilities

Manufacturing plants, warehouses, and distribution centers require roofs that can withstand harsh conditions. BUR's impact resistance and durability make it ideal for industrial environments.

High-Traffic Rooftops

Buildings with rooftop equipment like HVAC units, solar panels, or regular maintenance access need a roof that can handle foot traffic. The gravel surface provides excellent wear resistance.

Institutional Buildings

Schools, hospitals, and government buildings need reliable roofing that lasts decades. BUR's proven track record and fire resistance make it a preferred choice for public institutions.

Comparison

BUR vs Other Flat Roofing Systems

Feature
BUR
TPO PVC Mod. Bitumen
Lifespan 20-30 Years 15-30 Years 20-35+ Years 15-25 Years
Waterproofing Excellent Good Very Good Excellent
Fire Resistance Class A Class A Class A Class A
Foot Traffic Excellent Fair Good Very Good
Energy Efficiency Moderate Excellent Very Good Moderate
Installation Cost Moderate-High Low-Moderate High Moderate
Repairability Easy Moderate Moderate Easy

Highlighted column indicates where BUR excels compared to alternatives

Care & Upkeep

BUR Maintenance & Lifecycle

While BUR systems are incredibly durable, proper maintenance extends their lifespan and protects your investment. Here's what you need to know about keeping a BUR roof in top condition.

Semi-Annual Inspections

Professional inspections twice a year (spring and fall) catch potential issues before they become costly problems.

Debris Removal

Keeping the roof clear of leaves, branches, and debris prevents ponding water and extends the life of the surface layer.

Drainage Maintenance

Regular cleaning of drains, gutters, and scuppers ensures proper water flow and prevents standing water that can degrade the roof.

Reflective Coatings

Applying a reflective coating every 5-10 years reduces heat absorption, lowers energy costs, and extends the roof's service life.

Flat roof with gravels of an urban city dwelling house

BUR Lifecycle Timeline

Year 0-1
New installation — the roof settles and cures. Minor adjustments may be needed after the first winter.
Year 1-10
Peak performance with minimal maintenance. Biannual inspections recommended.
Year 10-15
Apply reflective coating to rejuvenate the surface and restore UV protection.
Year 15-20
More frequent inspections. Some minor repairs may be needed around flashings and penetrations.
Year 20-30
End of expected lifecycle. Plan for roof replacement or major restoration.
FAQ

Common BUR Questions

How long does a BUR roof typically last?

How much does a BUR roof cost?

Can BUR be installed over an existing roof?

Does BUR work on sloped roofs?

How does weather affect BUR installation?

Ready for a BUR Roof That Lasts Decades?

Our team of experienced commercial roofing specialists will assess your building, provide a detailed quote, and deliver a Built-Up Roofing system that protects your investment for 20-30 years or more.

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