# Modified Bitumen Roofing Systems

> Modified Bitumen Systems Commercial Roof System from Commercial Roofing of Atlanta: documented commercial roof scopes, inspections, repair, replacement.

Canonical: https://commercialroofingofatlanta.com/roof-systems/modified-bitumen-systems

Commercial Roof Systems

Modified bitumen SBS and APP roof system installation, recover, and repair for Atlanta commercial buildings - torch-applied, cold-process, and heat-weld systems with manufacturer warranty.

[Request this scope](https://commercialroofingofatlanta.com/contact)

Modified bitumen bridges Atlanta's built-up roofing history and modern single-ply technology. SBS and APP systems suit low-slope roofs with irregular geometry, high-penetration density, and existing BUR substrates where a single-ply recover is not practical.

Modified bitumen roofing - SBS (styrene-butadiene-styrene) and APP (atactic polypropylene) - emerged in the 1980s as a performance upgrade over traditional built-up roofing. In Atlanta, it filled the gap between aging BUR systems and the single-ply revolution: easier to detail around complex penetration patterns than single-ply, more durable than straight asphalt BUR, and available in torch-applied, heat-weld, and cold-process installation methods. A significant portion of Atlanta's 1990s and 2000s commercial building stock carries modified bitumen systems - mid-rise office buildings, strip retail, medical office buildings, schools, and institutional facilities.

SBS-modified bitumen remains relevant in Atlanta's current roofing market in specific applications: low-slope roofs with high penetration density that would require extensive custom detailing in single-ply, recover projects over existing BUR where the modified bitumen over-BUR stack is well-established by the existing system type, and buildings where the slope and geometry make the controlled lap installation of modified bitumen easier to execute to a high quality standard than single-ply seaming.

APP-modified bitumen, typically torch-applied, is also used in Atlanta but requires hot-work permit compliance - a requirement that adds pre-construction administration in the City of Atlanta and most Cobb and DeKalb County jurisdictions. Cold-process SBS eliminates the hot-work permit requirement and is our default modified bitumen specification where the application does not specifically require a torch-applied APP system.

SBS-modified bitumen is more flexible at low temperatures and tolerates Atlanta's thermal cycling range well. It is typically applied with cold-process adhesive, heat welding, or self-adhering systems, all of which eliminate the hot-work permit requirement that torch-applied APP requires. For Atlanta projects in the City of Atlanta, Cobb County, or DeKalb County - where hot-work permits require advance application and on-site fire watch - cold-process SBS is typically the lower-administrative-burden specification for modified bitumen projects.

APP-modified bitumen, torch-applied, produces a very robust lap seam when installed correctly and is the preferred specification for exposed (granule-surfaced) walkway and traffic applications. The torch application produces a direct-bond lap joint that some installers find more reliable to execute than cold-process adhesive seams in Atlanta's high-humidity summer installation window. The tradeoff is the hot-work permit, fire watch requirement, and the additional pre-construction administration those requirements impose.

Both SBS and APP systems carry 10 to 15-year manufacturer warranty paths - shorter than the 20-year NDL paths available for TPO and EPDM. For buildings where modified bitumen is the right system choice, we are explicit about this warranty term difference in the scope recommendation.

## How this roof scope moves.

We keep the sequence clear so owners, managers, and facility teams know what happens next.

### Document

Confirm roof access, active symptoms, membrane condition, drainage, penetrations, edge details, and visible moisture indicators.

### Scope

Separate immediate repair needs from recover, coating, replacement, warranty, or capital planning recommendations.

### Execute

Coordinate crew timing, tenant impact, material path, safety setup, closeout photos, and any warranty-related documentation.

## Related roof paths.

These related roof scopes help connect the current concern to repair, system, property, or service-area planning.

[Commercial Roof Systems TPO Roof Systems TPO single-ply roof system installation, recover, and warranty work for Atlanta commercial buildings - 60-mil and 80-mil systems with 20-year NDL paths, specified to Georgia.](https://commercialroofingofatlanta.com/roof-systems/tpo-roof-systems) [Commercial Roof Systems EPDM Roof Systems EPDM single-ply roof system installation, recover, and warranty work for Atlanta-area commercial buildings - 60-mil fully adhered and mechanically attached systems with manufacturer warranty paths.](https://commercialroofingofatlanta.com/roof-systems/epdm-roof-systems) [Commercial Roof Systems PVC Roof Systems PVC single-ply roof system installation for Atlanta commercial buildings - restaurant, food processing, and chemical-exposure environments where PVC's resistance to fats.](https://commercialroofingofatlanta.com/roof-systems/pvc-roof-systems) [Commercial Roof Systems Standing Seam Metal Roof Systems Standing seam metal roof system installation and assessment for Atlanta commercial buildings - architectural, industrial, and retrofit over-roofing applications with long-term manufacturer warranty paths.](https://commercialroofingofatlanta.com/roof-systems/standing-seam-metal-systems) [Commercial Roof Systems Modified Bitumen Roofing Systems Modified bitumen SBS and APP roof system installation, recover, and repair for Atlanta commercial buildings - torch-applied, cold-process, and heat-weld systems with manufacturer warranty paths.](https://commercialroofingofatlanta.com/roof-systems/modified-bitumen-systems) [Commercial Roof Systems Silicone Roof Coating Systems Silicone fluid-applied roof coating systems for Atlanta commercial buildings - restore aging single-ply and metal roof systems with 10 to 20-year manufacturer warranty paths.](https://commercialroofingofatlanta.com/roof-systems/silicone-roof-coating-systems)

## Need this reviewed on your building?

Send the roof location, photos, tenant schedule, and timing. We will route it to the right commercial roof scope.

[Contact the roof team](https://commercialroofingofatlanta.com/contact)

Commercial, industrial, and multifamily roof repair, replacement, coating, inspection, and maintenance scopes for Atlanta owners, managers, and facility teams.

[404-424-9759](tel:+14044249759)
[projects@commercialroofingofatlanta.com](mailto:projects@commercialroofingofatlanta.com)

### Plan

[Services](https://commercialroofingofatlanta.com/services)

[Roof Systems](https://commercialroofingofatlanta.com/roof-systems)

[Capabilities](https://commercialroofingofatlanta.com/capabilities)

### Repair

[Damage Repair](https://commercialroofingofatlanta.com/damage-repair)

[Commercial Roof Repair](https://commercialroofingofatlanta.com/services/commercial-roof-repair)

[Emergency Roof Repair](https://commercialroofingofatlanta.com/services/emergency-roof-repair)

### Atlanta

[Service Areas](https://commercialroofingofatlanta.com/service-areas)

[About](https://commercialroofingofatlanta.com/about)

[Contact](https://commercialroofingofatlanta.com/contact)

**Atlanta Service Map**

Copyright 2026 Commercial Roofing of Atlanta. All rights reserved. · [Privacy Policy](https://commercialroofingofatlanta.com/privacy) · [Terms of Use](https://commercialroofingofatlanta.com/terms) · [Site Map](https://commercialroofingofatlanta.com/sitemap.xml)