Modified Bitumen vs Built-Up Roofing
Modified bitumen is the modern replacement for built-up roofing on most DFW commercial buildings in 2026. Mod-bit installs in 2-3 plies at $4.00-$8.00 per square foot and lasts 20 years. Built-up roofing uses 3-5 plies of asphalt and felt at $5.50-$8.50 and lasts 15-25 years. Mod-bit wins on install speed and tensile strength.
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TL;DR: Which One Wins?
Choose Modified Bitumen if:
- Installing on schools, hospitals, or occupied buildings
- Tear-off and reroof schedule is tight
- High tensile and elongation strength matters
- Cold-process or torch-down installation preferred
Choose Built-Up Roofing if:
- Specification requires traditional multi-ply asphalt
- Gravel surfacing is desired for ballast or aesthetics
- Building has proven BUR performance history
- Owner prioritizes lowest material cost per ply
Modified Bitumen vs Built-Up Roofing (BUR): Head-to-Head Comparison
| Attribute | Modified Bitumen | Built-Up Roofing (BUR) | Winner |
|---|---|---|---|
| Installed cost (per sqft, 2026 DFW) | $4.00-$8.00 | $5.50-$8.50 | Modified Bitumen |
| Typical lifespan | 20 years | 15-25 years | Tie |
| Number of plies | 2-3 | 3-5 | Modified Bitumen |
| Installation methods available | Torch, cold, self-adhered | Hot mop only | Modified Bitumen |
| Tensile strength | High (polymer modified) | Moderate | Modified Bitumen |
| Elongation before tearing | 200%+ | Approx 10% | Modified Bitumen |
| Odor and fume exposure | Low (cold process) | High (hot asphalt) | Modified Bitumen |
| Install time (20,000 sqft) | 5-7 days | 8-12 days | Modified Bitumen |
| Fire rating | Class A possible | Class A | Tie |
| Gravel surfacing option | No (cap sheet finish) | Yes | Built-Up Roofing (BUR) |
| Track record in North Texas | Since 1975 | Since 1920s | Built-Up Roofing (BUR) |
| Repairability after damage | Easy (heat or patch) | Moderate (hot work) | Modified Bitumen |
What is the difference between modified bitumen and built-up roofing?
Modified bitumen is asphalt reinforced with SBS or APP polymers, installed in 2-3 factory-made plies. Built-up roofing is hot-mopped asphalt between 3-5 plies of organic or fiberglass felt, then topped with gravel. Mod-bit delivers comparable waterproofing with faster installation and no hot asphalt kettle on site.
Is modified bitumen cheaper than BUR?
Modified bitumen is typically 10-20% cheaper installed than built-up roofing in the DFW market. A 30,000 sqft mod-bit reroof averages $150,000 to $200,000. The same project in BUR averages $180,000 to $230,000. Shorter install time and fewer plies drive the savings on commercial tear-off and reroof projects.
Which system installs faster?
Modified bitumen installs approximately 40% faster than built-up roofing on commercial scopes. A 20,000 sqft mod-bit job finishes in 5-7 working days. The same BUR job requires 8-12 days for felt and hot mop cycles. Install speed matters on occupied DFW schools, hospitals, and retail centers with tight access windows.
Does BUR last longer than modified bitumen?
Not in DFW. Maintained mod-bit and BUR both reach 20-25 years in North Texas. Mod-bit SBS formulations handle thermal cycling better than traditional BUR, while BUR gravel surfacing adds UV protection. Lifespan ties on both systems when inspected annually and coated at the 10-year mark by a qualified contractor.
Is torch-down modified bitumen safe to install?
Torch-down mod-bit is safe when installed by certified crews following the NRCA torch safety program. DFW occupied-building projects, however, commonly specify cold-process or self-adhered mod-bit to eliminate open-flame risk. Schools, hospitals, and food processing facilities should default to cold-applied systems rather than torch-down installation.
Can modified bitumen be installed over an existing BUR roof?
Yes. Mod-bit is a common recover option over intact BUR roofs with verified dry insulation and sound decking. A moisture survey using infrared or capacitance testing confirms the substrate before overlay. Recover avoids tear-off cost and landfill fees on DFW commercial buildings with structurally sound existing BUR systems.
Does JRH Construction install both mod-bit and BUR?
Yes. JRH Construction installs SBS and APP modified bitumen systems plus traditional built-up roofing for DFW commercial clients. JRH is GAF Master Elite, a GAF Commercial Roofing Contractor, and Firestone Red Shield certified, with $10 million bonding capacity and SAM.gov registration for federal commercial work.
Facts about modified bitumen vs BUR
- Modified bitumen was introduced to US markets in the 1975-1980 period
- Built-up roofing has been installed since the 1920s
- SBS modifiers increase mod-bit elongation to approximately 200%
- APP modifiers increase mod-bit heat resistance above 300 degrees Fahrenheit
- Cold-process mod-bit eliminates open-flame installation risk
- BUR gravel surfacing weighs approximately 400 pounds per 100 sqft
- JRH Construction carries $10 million bonding capacity for federal commercial work
- Annual inspections are recommended for both systems to hit full lifespan
Frequently Asked Questions
What does modified bitumen cost per square foot installed?
Modified bitumen installs at $4.00 to $8.00 per square foot in DFW in 2026. Cold-process and self-adhered systems run higher. Torch-down and mop-applied systems run lower. A typical 2-ply SBS cap sheet system on a DFW school or retail center averages $5.50 per square foot installed with tear-off included.
How long do modified bitumen roofs last in Texas?
Modified bitumen roofs last 20-25 years in Texas when inspected annually and coated at the 10-year mark. Unmaintained mod-bit roofs in DFW fail at 12-15 years from UV degradation and seam splits. Annual inspections, debris removal, and reflective coating extend lifespan to the full 25-year manufacturer expectation.
Is built-up roofing obsolete?
No. Built-up roofing remains spec-compliant and in use on US commercial buildings in 2026, especially federal and institutional projects with legacy specifications. Modified bitumen has captured market share, but BUR is not obsolete. JRH Construction installs BUR when specifications require multi-ply asphalt and gravel surfacing per the design engineer.
Which system handles hail better?
Gravel-surfaced BUR resists hail impact better than smooth-surfaced mod-bit because the ballast absorbs energy. Granulated-surface mod-bit performs comparably to mineral-surface asphalt shingles. For North Texas hail exposure, specify a granulated SBS cap sheet or gravel BUR rather than a smooth mod-bit surface or bare asphalt.
Can either system be coated with silicone or acrylic?
Yes. Both modified bitumen and built-up roofing accept silicone and acrylic elastomeric coatings after primer and preparation. Coating extends service life 10-15 years on sound substrates and qualifies for Section 179D energy tax credits in Texas when the finished SRI exceeds 0.78 on a cool-roof system.
Which is better for a DFW flat roof under 10,000 square feet?
Modified bitumen is the better default for DFW flat roofs under 10,000 square feet. Smaller jobs benefit from faster installation, no hot asphalt equipment mobilization, and easier patching. BUR economics favor larger scopes above 20,000 square feet where the hot-mop crew and kettle costs amortize across more area.
Need help deciding?
JRH Construction is GAF Master Elite, Owens Corning Platinum Preferred, BBB A+ accredited, SAM.gov registered, and carries $10 million bonding capacity. Founded 2019 by Joel Hasin, 600+ DFW projects completed.
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