Commercial Roofing · Modified Bitumen

Modified Bitumen Roofing

A redundant, multi-ply asphalt membrane you can spot-repair for decades, and a proven way to re-cover an aging built-up roof without burying its problems.

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Polyglass

SBS & APP systems

Multi-ply

Redundant & repairable

Flame-free option

Cold/self-adhered SBS

Re-cover ready

Over sound, dry decks

What modified bitumen is

Modified bitumen is asphalt roofing brought into the modern era: asphalt modified with polymers (SBS or APP) and reinforced into rolled sheets that are installed in multiple plies. The result is a redundant, tough membrane that tolerates foot traffic and complex flashing, and that you can spot-repair for decades rather than replace wholesale.

We install Polyglass modified-bitumen systems. It’s an especially strong choice for roofs that see maintenance traffic, have a lot of penetrations, or are being re-covered over an aging built-up roof.

Permit to close-out, the sequence every commercial re-roof follows. Open full size

SBS vs. APP — two chemistries

SBS (rubberized): stays flexible in temperature swings and is often applied in cold-adhesive or self-adhered systems — useful on occupied buildings where open flame is a concern.
APP (plastic-modified): torch- or hot-mop-applied, with a tough weathering surface. Robust where it’s appropriate to use heat.

We choose the chemistry and application method around the building’s use and safety constraints, and we state it on the proposal.

Why multiple plies matter

A single-ply membrane is one line of defense; a multi-ply modified-bitumen roof has several. That redundancy is forgiving: a surface scuff or a future penetration doesn’t necessarily reach the deck, and repairs are straightforward. For owners who value ‘repairable for years’ over ‘cheapest sheet,’ mod-bit earns its keep.

Re-covering an old built-up roof

Modified bitumen is a common, code-permitting, cost-effective way to re-cover a sound but aging built-up roof without a full tear-off, when the deck is dry and the building can carry the layer. We verify both before recommending it; a re-cover over a wet or failing substrate just buries the problem.

System

TPO

Single-ply reflective alternative.

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System

Built-Up Roofing

Maintaining the roof you have.

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Hub

All Systems

Compare the four commercial systems.

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Common questions

Is modified bitumen outdated compared to TPO?

No — they solve different problems. TPO is a reflective single-ply sheet; modified bitumen is a redundant multi-ply membrane that’s easy to repair and tolerant of traffic and complex details. Plenty of new commercial roofs are still specified in mod-bit for exactly those reasons.

Do you torch it on? Is that safe on an occupied building?

Not necessarily. SBS modified bitumen can be installed with cold adhesive or as a self-adhered system, with no open flame — which is often the right call on an occupied building. We pick the application method around the building’s safety constraints and tell you which we’re using.

Can modified bitumen go over my existing roof?

Often yes, as a re-cover over a sound, dry built-up or mod-bit roof where code permits the added layer. If the substrate is saturated or the building is at its layer limit, it has to come off first. We check before quoting.

How long does a modified-bitumen roof last?

A well-installed, maintained multi-ply system commonly serves around two decades, and because it’s repairable, its practical life is often extended further with maintenance. As always, the install quality and the drainage matter more than any single number.

Have an aging flat roof you’re not ready to tear off?

We’ll check whether the deck is sound and dry, tell you if a mod-bit re-cover is the honest money-saver or if it’s time for a full replacement, and spec it in writing.

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Modified-bitumen roofing across Miami-Dade, Broward, and West Palm Beach.