--- title: "Commercial Roofing" description: "EPDM, TPO, Duro-Last, PVC, modified bitumen, built-up, and coating restorations for commercial buildings — installed around your tenants." canonical: "https://cmac-new-concept.vercel.app/services/roofing/commercial-roofing" last-modified: "2026-08-24" --- # Commercial Roofing > EPDM, TPO, Duro-Last, PVC, modified bitumen, built-up, and coating restorations for commercial buildings — installed around your tenants. Canonical: https://cmac-new-concept.vercel.app/services/roofing/commercial-roofing Last updated: 2026-08-24 CMAC Commercial Roofing: trusted and reliable. EPDM, TPO, Duro-Last, PVC, modified bitumen, built-up, and coating restorations for commercial buildings — installed around your tenants. [Request Inspection](https://cmac-new-concept.vercel.app/quote) ## Commercial Roofing, clearly scoped. Need EPDM, TPO, Duro-Last, or roof coatings? CMAC guides you to the right commercial solution for the building you actually have — its slope, its drainage, its insulation, its rooftop equipment, and whether anyone is working underneath it while the work happens. CMAC also installs composition, metal, tile, and slate commercially, for churches, offices, retail, and mixed-use buildings where the roof is part of the architecture. ## Single-ply, modified bitumen, and built-up Built-up roofing is the original low-slope system: alternating plies of felt and bitumen built into a laminated membrane, usually surfaced with gravel. It is redundant by design and repairs well, and it is heavy, slow to install, and hot and odorous to build. Modified bitumen took the same asphalt chemistry and added polymer modifiers — SBS for flexibility in cold, APP for heat resistance — delivered in rolls that are torched, mopped, cold-applied, or self-adhered, typically as a base sheet and a cap sheet. It keeps the multi-ply redundancy of BUR with far less field labor. Single-ply is the modern default. EPDM is a synthetic rubber sheet that has been proven in the toughest climates for over thirty years, and it handles temperature extremes and UV about as well as anything on the market. TPO is a thermoplastic sheet, typically white and highly reflective, and it is the fastest-growing product in commercial roofing. PVC is the other thermoplastic, chosen where the roof sees grease, chemicals, or restaurant exhaust, which degrade other membranes. Duro-Last is prefabricated PVC. The panels and flashings are fabricated in the plant to the building’s measured dimensions and pre-welded there, so a large share of the seam work is done under factory conditions instead of on a windy roof, and rooftop labor drops accordingly. ## Seams are where roofs fail The difference between the thermoplastics and EPDM comes down to the seam. TPO and PVC are hot-air welded: the two sheets fuse into a single homogeneous mass, and a properly made weld is generally stronger than the sheet on either side of it. EPDM sheets are joined with primer and seam tape — a bond that works well when the surfaces are clean and correctly primed, and which has historically been the weak point of the system when they are not. Neither is disqualifying; it just means EPDM quality lives in seam prep and thermoplastic quality lives in weld temperature and technique, and both are checked by probing seams after they cool. ## Attachment method - Mechanically attached. Fasteners and plates through the membrane along the seam lines, covered by the next sheet. Fast and economical, and the membrane flutters under wind uplift, which drives more air movement into the assembly. - Fully adhered. Bonding adhesive across the entire field. Best wind uplift performance, the smoothest finished appearance, and the most sensitive to substrate condition, temperature, and moisture at the time of install. - Ballasted. Loose-laid membrane held down by river rock or pavers. Inexpensive and quiet, and it adds substantial dead load, makes leak location difficult, and performs poorly in high-wind zones. ## Drainage, ponding, and tapered insulation Positive drainage means the roof sheds standing water within about forty-eight hours of rainfall. Water that stays past that adds real dead load — roughly five pounds per square foot for every inch of depth over the ponded area — accelerates membrane weathering, grows biological matter, deposits dirt that defeats a reflective roof, and voids most manufacturer warranties. The fix is rarely the membrane. It is tapered polyiso insulation built into a slope, usually an eighth or a quarter inch per foot, with crickets between and behind drains to move water rather than trap it, plus adequate drains, overflow scuppers, and clear sumps. ## Insulation and code minimums Energy code sets a minimum roof insulation R-value by climate zone, and a reroof is usually the moment a building has to meet the current one. Polyisocyanurate is the common choice at roughly five and a half to six R per inch. Two staggered layers outperform a single thick layer, because the offset joints break the thermal bridging that runs straight through aligned seams. A cover board over the insulation protects the membrane from foot traffic and improves hail performance, and it is the cheapest durability upgrade available on a commercial roof. ## When a coating restoration beats a tear-off Elastomeric, silicone, and acrylic coating systems can restore a roof that is fundamentally sound: the membrane is watertight or repairable, the seams and flashings can be reinforced, and — this is the part that decides it — the insulation underneath is dry. Core cuts or an infrared scan answer that question. A restoration re-establishes a reflective, monolithic surface, extends service life, carries its own warranty, and avoids the disruption and disposal of a tear-off entirely. When the insulation is saturated, a coating is money spent sealing water inside the assembly, where it keeps destroying the deck and keeps costing you in energy. That roof needs a tear-off, and being told so is more valuable than being sold a coating. ## Working over an occupied building On an occupied building the schedule is set by the tenants, not the crew. Tear-off is loud directly below, and torch and hot-asphalt work carries odor into the return air unless intakes are managed. Work gets staged so no section is left open at the end of a shift, sequenced around business hours and around whatever is happening under that specific bay, and coordinated so egress routes, fire lanes, and parking stay usable. Interiors below active work get protected, and crane and material staging gets planned against the tenant’s dock and traffic patterns rather than against ours. ## What commercial roofing includes ### EPDM Synthetic rubber single-ply, proven in the toughest climates for over thirty years. ### TPO Reflective hot-air-welded thermoplastic — the fastest-growing product in commercial roofing. ### Duro-Last Prefabricated PVC with panels and flashings welded to the building’s dimensions in the plant. ### Coating restoration Elastomeric, silicone, and acrylic systems that extend a sound roof without a tear-off. ### Modified bitumen and BUR Multi-ply asphalt systems where redundancy and repairability matter more than speed. ### Drainage correction Tapered insulation, crickets, and drain work to get standing water off the roof. ## How CMAC handles commercial roofing 1. **Roof survey** — Slope, drainage, existing assembly, insulation condition, penetrations, and rooftop equipment are documented, with core cuts or scanning where moisture is suspected. 2. **System recommendation** — Membrane, attachment method, insulation and R-value, and restoration-versus-replacement are recommended against the building and its use. 3. **Scope and scheduling** — The scope is written out and the phasing is set around tenant hours, dock access, egress, and the areas below each section of work. 4. **Installation** — Work runs in sections that are closed in daily, with seams probed, flashings and terminations detailed, and drainage verified. 5. **Warranty and maintenance** — The manufacturer warranty is registered and a maintenance interval is set, because most commercial warranties require documented upkeep. ## Systems and manufacturers - **Duro-Last** — Prefabricated PVC commercial membrane - **GAF** — Master Elite® certified — full shingle system ## Commercial Roofing questions ### What does GAF Master Elite® mean? GAF awards Master Elite® status to a small fraction of roofing contractors in North America. It requires proof of proper licensing, adequate insurance, and a sustained record of quality installations and customer satisfaction. Practically, it means CMAC can offer enhanced GAF system warranties that non-certified contractors cannot, and that GAF has independently vetted the company. CMAC is also a GAF President’s Club award winner. ### Do you charge for an inspection or an estimate? No. The inspection, the damage documentation including drone photography, and the written estimate are all free and carry no obligation. If the roof does not need work, we will tell you that. ### Will CMAC work with my insurance company? CMAC can document visible damage, provide a contractor report, and attend the carrier’s inspection to explain the proposed repair scope. CMAC is a contractor, not a public adjuster or law firm, and does not interpret policy coverage or represent a policyholder in a coverage dispute. ### How do I know whether to repair or replace my roof? Age relative to the material’s service life, how widespread the damage is, and whether you have had more than one leak are the deciding factors. Isolated damage on a roof with years of life left is a repair. Widespread granule loss, exposed mat, multiple leak points, or hail bruising across every slope generally means replacement, because patching a failing system just moves the next leak somewhere else. An inspection settles it. ### How long does a roof replacement take? Most residential asphalt shingle replacements are a one to two day job once materials are on site. Tile, slate, metal, and complex roof geometry take longer. Weather, decking replacement discovered after tear-off, and permit or HOA requirements are the usual reasons a schedule moves. ### My roof looks fine from the ground. Could it still be damaged? Frequently, yes. Hail bruises the mat underneath the granule surface, and that bruising is often invisible from the ground and sometimes hard to see from a ladder. It shortens the roof’s life and creates the leaks you will discover a year or two later, after your claim window has closed. That is why documented post-storm inspections matter. ## Related services - [Roofing](https://cmac-new-concept.vercel.app/services/roofing) - [Multi-Family & Property Management](https://cmac-new-concept.vercel.app/services/roofing/multi-family) - [Roof Repair](https://cmac-new-concept.vercel.app/services/roofing/roof-repairs) - [Specialty Roofing Systems](https://cmac-new-concept.vercel.app/services/roofing/specialty-systems) ## Start with a free inspection. Tell CMAC what is happening at the property. We will inspect the condition and put the recommended scope in writing. [Request Inspection](https://cmac-new-concept.vercel.app/quote) [Call 1-888-389-CMAC](tel:+18883892622) ## Sources - https://www.cmacroofing.com/commercial-roofing