01
ROOF DECK
The structural deck supports the weight of the roof and must be evaluated for condition and attachment.
MULTI-PLY • BITUMEN • REINFORCED LOW-SLOPE SYSTEM
BUILT-UP ROOFING IN ATLANTA, GA
Built-up roofing, commonly called BUR, creates a low-slope commercial roof from multiple layers of bitumen and reinforcement, producing a redundant waterproofing assembly with a long commercial roofing history.
MULTI-PLY COMMERCIAL ROOF
ASPHALT-BASED SYSTEM
REDUNDANT WATERPROOFING
ATLANTA, GA
QUICK ANSWER • WHAT IS BUILT-UP ROOFING?
Built-up roofing is a multi-ply low-slope roof system assembled from alternating layers of bitumen and reinforcing felts or fabrics, then protected with an approved surfacing. Depending on the specification, surfacing may include aggregate, a coated surface or another compatible finish. BUR is valued for redundancy because water must get through multiple waterproofing layers rather than a single membrane sheet.
BUILT-UP ROOF SYSTEM ANATOMY
MULTIPLE LAYERS. ONE CONTINUOUS WATERPROOFING ASSEMBLY.
BUR systems earn their name literally: the roof is built up in place. Deck conditions, insulation, base layers, bitumen, reinforcing plies, flashing membranes, surfacing, edge details and drainage all affect the final roof rather than one factory-made membrane doing the entire job.
02
INSULATION / COVER BOARD
Thermal layers and a stable substrate help establish drainage and support the roofing plies.
03
BASE LAYER
A compatible base sheet or initial ply provides the transition between substrate and the built-up membrane.
04
BITUMEN
Hot asphalt or approved cold-applied bituminous materials bond and waterproof the reinforcing layers.
05
REINFORCING PLIES
Multiple felt or fabric plies create redundancy and distribute stresses throughout the roof membrane.
06
SURFACING
Aggregate, coating or another approved finish protects the asphaltic membrane from ultraviolet exposure and wear.
WHERE BUILT-UP ROOFING MAKES SENSE
REDUNDANCY FOR COMMERCIAL ROOFS THAT NEED A TOUGH MULTI-PLY ASSEMBLY.
BUR is often found on established commercial, institutional and industrial buildings with low-slope roofs. It may be considered where owners value multi-ply redundancy, durable surfacing and compatibility with an existing asphalt-based roof, particularly when the building and structure can support the assembly.
- Large low-slope commercial roofs
- Existing BUR assemblies needing repair or replacement
- Buildings where multi-ply redundancy is a priority
- Roofs exposed to regular maintenance activity
- Projects that can accommodate installation logistics and material handling
- Assemblies where roof weight and deck capacity have been reviewed
BUR VS. OTHER COMMERCIAL LOW-SLOPE SYSTEMS
REDUNDANCY HAS BENEFITS. IT ALSO ADDS WEIGHT AND LOGISTICS.
| System | Type | Seams / Joints | Standout Advantage | Watch Closely |
|---|---|---|---|---|
| Built-Up Roofing | Bitumen + multiple reinforcing plies | Field-built layers | Redundancy + durable surfacing | Weight, logistics, surfacing, drainage |
| Modified Bitumen | Factory-made modified asphalt sheets | Product-specific laps | Reinforced sheets + asphalt compatibility | Application method, heat, laps, weight |
| TPO | Thermoplastic single-ply | Heat welded | Reflectivity + lighter assembly | Weld quality, punctures, drainage |
| EPDM | Synthetic rubber single-ply | Tape / adhesive seams | Large sheets + flexibility | Seams, punctures, traffic protection |
OTHER COMMERCIAL ROOF SYSTEMS
COMPARE THE ALTERNATIVES BEFORE LOCKING THE SPECIFICATION.
The right system starts with slope, deck, drainage, rooftop use, exposure, existing materials and ownership goals. These related commercial roof systems solve different problems and should not be treated as interchangeable products.
01
TPO ROOFING
Thermoplastic single-ply with heat-welded seams for low-slope commercial roofs.
EXPLORE TPO ROOFING →
02
EPDM ROOFING
Synthetic-rubber single-ply roofing with flexible sheets and proven repair methods.
EXPLORE EPDM ROOFING →
03
PVC ROOFING
Thermoplastic membrane with welded seams and strong resistance to many grease and chemical exposures.
EXPLORE PVC ROOFING →
04
MODIFIED BITUMEN
Reinforced asphalt-based sheets that create durable multi-layer low-slope assemblies.
EXPLORE MODIFIED BITUMEN →
05
COMMERCIAL METAL
Panel and standing-seam systems built around movement, attachment and flashing control.
EXPLORE COMMERCIAL METAL →BUR INSTALLATION PRIORITIES
MORE LAYERS DO NOT EXCUSE BAD DRAINAGE OR BAD DETAILS.
01
STRUCTURE + ASSEMBLY REVIEW
Confirm deck condition, existing roof composition, moisture, attachment and whether the structure is suitable for the specified system.
02
TEAR-OFF / RECOVER DECISION
Determine what must be removed and what, if anything, can remain under code and system requirements.
03
INSULATION + SLOPE
Build the thermal and drainage package before membrane plies lock the roof profile in place.
04
PLY APPLICATION
Install bitumen and reinforcing layers at the specified coverage, overlap and sequence.
05
FLASHING + PENETRATIONS
Integrate walls, curbs, drains and penetrations into the multi-ply membrane rather than treating them as separate repairs.
06
SURFACING + QUALITY CONTROL
Complete the protective surface, check drainage and terminations, and correct voids or exposed asphalt before closeout.
THE POINT:
BUR is famous for redundancy, but standing water, saturated insulation and weak flashing can defeat redundant plies just as efficiently as they defeat newer systems. Old technology still obeys physics. Irritating, but consistent.
REPAIR, RECOVER OR REPLACE?
START WITH THE ROOF THAT IS ACTUALLY THERE.
Before recommending a commercial roof project, Ameristar Roofing can evaluate membrane or panel condition, moisture, insulation, deck concerns, drainage, penetrations, previous repairs and the remaining usefulness of the existing assembly.
A small leak does not automatically mean full replacement. The opposite is also true: a roof covered in patchwork is not automatically a good repair candidate just because another bucket of sealant can be purchased.
The decision should be based on the extent of deterioration, trapped moisture, attachment, recurring leak history, building plans and whether a repair or recover can reasonably restore dependable performance.
BUILT-UP ROOFING FAQS
THE QUESTIONS THAT SHOULD BE ANSWERED BEFORE THE PROJECT.
What does BUR roofing mean?
BUR stands for built-up roofing. It is a low-slope commercial roof assembled from multiple layers of bitumen and reinforcing materials with a protective surface.
How many plies are in a built-up roof?
The number of plies varies by specification. A roofing contractor should identify the actual existing assembly rather than assume ply count from the roof surface.
What is the top surface of a BUR roof?
Traditional BUR may use aggregate surfacing, while other assemblies use coatings, mineral surfaces or compatible finishes depending on the system.
Can a built-up roof be repaired?
Many localized blisters, splits, flashing failures and damaged areas can be repaired when the surrounding roof and underlying materials remain serviceable and dry.
Is built-up roofing heavy?
It can be heavier than many single-ply systems, particularly with aggregate surfacing. Roof structure and existing layers should be evaluated before adding or replacing a BUR assembly.
What is the difference between BUR and modified bitumen?
BUR is field-built from alternating bitumen and reinforcing plies. Modified bitumen uses factory-manufactured reinforced asphalt sheets modified with polymers such as SBS or APP.
When is BUR replacement more appropriate than repair?
Replacement becomes more likely when moisture is widespread, insulation or deck deterioration is significant, repeated leaks occur across multiple areas, flashing systems are broadly failing or the assembly has reached a point where repairs no longer restore dependable performance.
AMERISTAR ROOFING • ATLANTA, GA
BUILD THE ROOF AROUND THE BUILDING.
Ameristar Roofing can inspect the existing commercial roof, evaluate the assembly and help determine whether built-up roofing belongs in the repair, recover or replacement plan.
(770) 338-6361