TPO vs. EPDM on Older Cleveland Commercial Buildings: How to Choose

Greater Cleveland has a large inventory of commercial buildings constructed between the 1950s and 1980s — former manufacturing facilities, warehouse conversions, professional office buildings, and retail strips — most of which have flat or very-low-slope roofs. When those roofs need replacement, the choice between TPO and EPDM isn't obvious, and the wrong call can cost a building owner significantly over a 15-to-20-year warranty period.

What Makes Older Cleveland Buildings Different

Buildings from this era were designed with different assumptions about energy codes, drainage standards, and roofing system lifespans than modern construction. The roof decks are often steel or concrete with limited slope — sometimes as little as 1/8 inch per foot — and the drainage infrastructure frequently has fewer drains than current code would require for the same roof area. Both of these conditions affect membrane selection.

Parapets on these buildings are often masonry — brick or block — which introduces a different set of flashing requirements than a wood-framed building. Counter-flashing into masonry needs to account for thermal movement and long-term sealant failure in ways that sheet-metal terminations into wood framing don't.

The Case for TPO

TPO (thermoplastic polyolefin) membranes are heat-welded at the seams, creating a continuous waterproof layer rather than a mechanically lapped joint. This matters on low-slope roofs with limited drainage because seam integrity is the most common point of failure over time, and a welded seam is significantly more resistant to blow-off and water infiltration than an adhesive or tape-seamed joint.

TPO's reflective white surface is also energy-code advantageous — particularly relevant for buildings with inadequate insulation that are working to reduce cooling loads. In Ohio's warm summers, the surface temperature differential between a white TPO roof and a black EPDM membrane is significant.

The Case for EPDM

EPDM (ethylene propylene diene monomer) is a rubber membrane that has been in commercial use for over 50 years. Its track record is well-established, and it performs reliably in the freeze-thaw conditions that Northeast Ohio produces. On irregular rooftops with numerous penetrations — exhaust vents, HVAC equipment, pipe stacks — EPDM's flexibility and the availability of pre-formed flashings for common penetration types can simplify installation and reduce the number of field-fabricated details that represent future failure points.

Fully adhered EPDM is also a strong choice when a building has a concrete deck with limited fastener options. TPO can be mechanically attached, but adhesive EPDM on concrete is a well-proven assembly with good long-term performance data.

How We Decide

The right system for any specific building in Cleveland depends on roof geometry, drainage configuration, the condition of the existing deck, the building's energy situation, and the owner's warranty expectations. Allied Roofing evaluates all of these before making a system recommendation. We're certified applicators for major manufacturers of both systems — our recommendation is based on what performs best for your building, not which system is faster to install. Call (330) 425-0767 or visit our TPO and EPDM services page.