A single-ply roofing system uses one flexible membrane layer as the primary waterproofing surface within a larger roof assembly. Commercial systems commonly use TPO, PVC, or EPDM membranes over insulation, cover board, or other approved substrates. The right membrane depends on the building, not on one headline benefit.
Mid-West Roofing Systems provides commercial single-ply roofing across North Dakota, South Dakota, and Minnesota. Call (701) 500-9399 to discuss the roof condition and the factors that should be reviewed before a membrane is selected.
Why Get a Single-Ply Roofing System?
Single-ply roofing can provide a continuous waterproof surface for flat and low-slope commercial roofs while keeping the roof assembly relatively lightweight. TPO and PVC are thermoplastic membranes with heat-welded seams. EPDM is a synthetic rubber membrane whose seams are generally joined with system-specific tape or adhesive materials.
Single-ply membranes can be installed using different attachment approaches depending on the membrane, roof deck, building design, wind requirements, and project specification. Fully adhered and mechanically attached assemblies are common, while some projects may use other approved attachment methods. The membrane should not be chosen separately from the deck, insulation, drainage, flashing, and rooftop-use conditions that support it.
Energy performance also depends on the complete roof and building. Light-colored TPO and PVC membranes are commonly selected when reflectivity is part of the project goal, while EPDM is commonly black and is also available in lighter options. Insulation thickness and condition, HVAC operation, occupancy, exposure, and roof color all affect the building result, so no fixed savings percentage should be assumed from membrane choice alone.
Choosing Between TPO, PVC, and EPDM
Mid-West Roofing Systems can help you choose a membrane by comparing the roof and building conditions that affect system selection. The matrix below shows what should be confirmed before one option is recommended.
| Factor | What to Confirm | How It Affects Selection |
|---|---|---|
| Substrate condition | Whether the deck and any retained roof components are sound, sufficiently dry, and suitable for the proposed assembly. | TPO, PVC, and EPDM all depend on a serviceable supporting assembly. A new membrane does not correct deteriorated decking or unresolved moisture. |
| Drainage | How water reaches drains, scuppers, or edges and whether recurring ponding or blocked drainage needs correction. | None of the three membranes should be expected to correct an underlying slope or drainage defect. |
| Attachment method | Deck type, wind design, roof geometry, and whether the specified system will be fully adhered, mechanically attached, or use another approved method. | The attachment approach must fit both the membrane system and the building conditions. |
| Insulation | Type, condition, thickness, and compatibility of insulation that will remain or be installed. | Insulation is a separate roof-assembly decision that affects thermal performance, attachment, and moisture planning for any membrane. |
| Rooftop activity | Where technicians walk, how often equipment is serviced, and whether protective walkways or traffic controls are needed. | All membrane types can be damaged by concentrated traffic, so service paths and protection should be planned before installation. |
| Detailing | How curbs, walls, penetrations, drains, edges, and transitions will be flashed and terminated. | TPO and PVC use heat-welded seam techniques, while EPDM uses different system-specific seam materials, so detailing and repair methods are not interchangeable. |
| Service access | How future inspectors, maintenance crews, and equipment technicians will reach and work on the roof. | A membrane system should remain practical to inspect, maintain, and repair after installation. |
Seam and Repair Compatibility
Repair materials and preparation should match the existing membrane system and the specific defect. TPO and PVC seams are normally heat-welded, while EPDM repairs use compatible rubber-membrane repair materials and seam products rather than thermoplastic welding.
Before recommending a repair, the contractor should identify the existing membrane type, review its condition, determine whether prior coatings or contaminants affect adhesion, inspect the surrounding substrate and insulation, and confirm that compatible repair materials are available. A patch chosen for another membrane type should not be treated as interchangeable simply because it can be placed over the damaged area.
This article focuses on system selection. The actual installation or repair procedure should be defined separately in the project-specific scope after the roof and membrane have been identified.
Why Choose Mid-West Roofing Systems?
Mid-West Roofing Systems serves commercial property owners across North Dakota, South Dakota, and Minnesota and provides single-ply roofing within its broader commercial roofing services. The company emphasizes straightforward communication and works with owners to evaluate the roof before recommending a system.
You can review examples in our project gallery and ask how the proposed membrane, attachment, insulation, drainage, detailing, and future maintenance plan fit your building. A useful proposal should explain those decisions rather than relying on generic claims about durability, maintenance, or energy savings.
Call to Discuss Single-Ply Roofing
To discuss TPO, PVC, or EPDM options for a commercial building, call Mid-West Roofing Systems at (701) 500-9399 or reach out through the contact page.
Frequently Asked Questions
How do I know whether TPO, PVC, or EPDM is right for my building?
The choice should follow the roof’s substrate, drainage, insulation, attachment requirements, rooftop activity, detailing, and future service access rather than one general benefit.
Can a different membrane type be used to patch an existing single-ply roof?
Repair materials should be compatible with the existing membrane and repair detail. TPO and PVC use thermoplastic welding methods, while EPDM relies on different system-specific repair and seam materials.
Does single-ply roofing automatically lower energy costs?
No. Roof color, insulation, HVAC operation, occupancy, exposure, and the complete building assembly affect energy performance, so savings should be evaluated for the specific project.
Does choosing a single-ply membrane eliminate the need for roof maintenance?
No. Inspection and maintenance needs depend on the membrane, installation, drainage, rooftop traffic, repairs, and building conditions over time.