
Modified Bitumen Roofing Repair & Replacement in NJ & PA
Multi-ply asphalt system reinforced with polymer modifiers (SBS or APP) providing redundant waterproofing layers and puncture resilience.
20 to 25+ years
Full system multi-ply warranty + repair guarantee
30+ Years Commercial Experience
Engineered commercial performance for Modified Bitumen.
Modified Bitumen combines traditional asphalt waterproofing with modern polymers (SBS rubber or APP plastic) and heavy fiberglass or polyester reinforcement mats. The result is a rugged, multi-ply roofing system that offers built-in redundancy: if the top cap sheet is punctured or scuffed by rooftop workers, the underlying base ply continues to block water. Datum Roofing installs cold-applied, self-adhered, and torch-applied modified bitumen systems.
Why Property Owners Choose Modified Bitumen
- Multi-ply redundant waterproofing — multiple layers of continuous protection
- Outstanding tensile strength and resistance to physical puncture
- Exceptional performance on high-traffic rooftop terraces and utility zones
- Mineral granulated cap sheets provide built-in UV and weathering defense
- Flexible in cold weather (SBS) or heat-resistant in direct sun (APP)
Datum Installation Process
Installed as a two-ply or three-ply assembly utilizing SBS base sheet and granule-surfaced cap sheet, bedded in cold adhesive or heat-welded.
Coastal Wind & Weather Engineering
Heavy multi-ply mass and continuous adhesion make Mod-Bit exceptionally stable against coastal wind scour and flying storm debris.

Best Suited For
- Condos with frequent HVAC servicing or rooftop equipment access
- Schools, healthcare facilities, and multi-family residential complexes
- Properties with complex parapets, multiple penetrations, and tight curbs
- Low-slope roofs requiring tough foot-traffic resistance
Datum Modified Bitumen Repair Capabilities
- Cold-process mastic and reinforcing mesh three-course patch repairs
- Torch or heat-weld seam re-adhesion and bleed-out checks
- Parapet base tie-in and coping metal resealing
- Drain bowl clamp replacement and membrane flange re-bedding
Our estimating process for Modified Bitumen Projects: thorough by design, zero surprises.
With deep roots in engineering and structural restoration, Datum takes existing conditions seriously. In commercial roofing, change orders are often treated as business as usual — but to us, too many change orders are a black mark. Our estimating is always 100% free, but engineered to be exhaustive before work begins.
Only 6% of our roof replacements involve a change order.
That low rate is the direct result of core samples, deck verification, and moisture scans completed before we price the work.
Projects finish on time — and yes, we're proud of that .7%!
Detailed phasing, tenant coordination, and weather buffers keep condominium boards and owners on schedule.
Exhaustive existing condition analysis at no charge.
Full condition audit, core cuts, moisture maps, and written replacement vs. repair options for your board or management company.
1. Core sampling & deck verification
We take physical core cuts through the membrane to verify the exact assembly underneath — number of existing plies, insulation type and thickness, substrate condition, and deck type (concrete, metal, wood, gypsum). No guessing.
2. Thermal moisture scanning
Non-destructive electronic moisture meters and infrared thermal imaging map trapped moisture pockets across the roof deck so wet insulation is quantified before the proposal is written — not discovered during tear-off.
3. Ventilation & intake/exhaust analysis
We calculate intake, exhaust, and rooftop airflow dynamics to prevent condensation, pressure imbalance, and premature membrane failure. A low-slope roof without proper ventilation engineering traps moisture from below.
4. Structural condition & load review
Drawing on Lasher's 30+ years in structural restoration and engineering, we evaluate parapets, expansion joints, deck deflection, and drainage slopes so every structural constraint is solved in the upfront scope.
Explore our full commercial roofing portfolio

TPO
Thermoplastic polyolefin single-ply membranes — energy efficient, heat-welded seams, and eligible for our industry-leading 35-year warranty on new systems.
Learn more
EPDM
Time-tested thermoset synthetic rubber membrane with over 50 years of proven real-world durability and extreme temperature flexibility.
Learn more
PVC
Premium single-ply thermoplastic membrane with supreme resistance to rooftop animal fats, oils, jet fuels, and industrial chemicals.
Learn more
Built-Up Roofing
Classic multi-ply hot asphalt and reinforcing plies topped with protective flood coat and gravel ballast for maximum puncture protection.
Learn more
Spray Polyurethane Foam
Monolithic, self-flashing closed-cell foam that insulates and waterproofs in a single seamless layer, finished with a protective elastomeric coating.
Learn more
Metal Roofing
Structural standing-seam and low-slope metal systems engineered for 50+ year lifespans, supreme coastal wind resistance, and modern architectural aesthetics.
Learn more
Roof Coatings
High-solids silicone and elastomeric fluid-applied coatings that restore an aging roof, eliminate leaks, and extend service life by 10-20 years without a tear-off.
Learn more
Architectural Shingles
Dimensional and architectural asphalt shingles for steep-slope commercial, multi-family, and mixed-use buildings — impact-resistant, wind-rated, and backed by manufacturer warranties.
Learn more
Slate Roofing
Precision repair, copper valley restoration, and replacement of natural quarry slate roofing on institutional, historical, and high-end condominium properties.
Learn moreModified Bitumen roofing across NJ, Philadelphia & the Mid-Atlantic
Datum Roofing installs and repairs Modified Bitumen systems for condominiums, commercial, and industrial properties throughout our service area. Find your local commercial roofing page.
Schedule a Modified Bitumen roof assessment.
Whether you need leak repair, seam maintenance, a condition audit for your condo reserve study, or a full replacement quote, our Linwood-based team responds promptly.
Request a Modified Bitumen Roofing Quote.
Tell us about the property and roof condition. We'll follow up within one business day.
