Fort Worth's older commercial buildings carry significant ballasted single-ply inventory — mostly EPDM installed in the 1980s and 1990s. We assess, recover, and replace ballasted systems. We explain directly why we rarely specify ballasted for new work in Tarrant County.

Ballasted roofing uses weight — typically 1.5-inch smooth river stone at 10-12 pounds per square foot — to hold a loose-laid single-ply membrane (EPDM or occasionally CSPE) against the deck without mechanical fasteners or adhesive. The system was standard for large-format commercial buildings across Fort Worth from the late 1970s through the mid-1990s because it was fast and economical to install. A significant volume of that inventory is still in service.

Our relationship with ballasted roofing is primarily on the assessment and recovery side. We inspect a lot of it — 1985 EPDM under 20-year-old river stone on East Loop 820 industrial buildings, , aging systems on the older commercial stock in the Ridgmar and Wedgwood neighborhoods. These buildings are making replace-versus-recover decisions, and we help them make the right call.

We will be straightforward about new-specification ballasted work: we rarely spec it. The wind-uplift performance concerns in Tarrant County's storm exposure, the dead-load implications for aging structural decks, and the operational limitations that ballast creates (it has to be moved for any repair or inspection work) make mechanically-attached single-ply a more defensible specification for essentially any new commercial building in the Fort Worth area.

Why We Rarely Spec Ballasted Systems for New Fort Worth Work

Wind uplift is the primary concern. Ballasted single-ply relies on the stone weight to resist wind-uplift forces. In standard Exposure B conditions — the Tarrant County default — 10-12 lbs per square foot of stone provides adequate resistance for typical wind events. But Fort Worth is not a standard wind environment. The Tarrant County corridor sees storm fronts with sustained winds of 50-70 mph and gusts in excess of 80 mph in severe thunderstorm events. Under those conditions, ballast stone mobilizes at roof edges and in field areas where the stone pack has migrated or been disturbed. A mobilized stone blown off a three-story commercial building in a Sundance Square storm event creates a public safety problem that a mechanically-attached membrane cannot create.

Dead load is the second concern. 10-12 lbs per square foot of ballast stone represents a significant structural dead load. Most Fort Worth commercial buildings built through the 1990s were designed for the roof dead load of the ballasted system installed at original construction. When the ballasted system reaches end of life and recovery is on the table, a second ballasted recover may exceed the structural deck's capacity — we verify structural capacity with the engineer of record before specifying any recover. Mechanically attached systems eliminate this issue entirely.

Operational access is the third concern. Any repair, penetration addition, or inspection work on a ballasted system requires stone removal, which is labor-intensive and time-consuming. Building owners accumulate rooftop equipment and conduit over a building's life — every addition to a ballasted roof requires stone excavation and replacement. Mechanically attached systems allow access to the membrane at any point without material removal.

Ballasted System Assessment and Recovery Options

The most common ballasted system recovery we perform in Fort Worth is mechanically-attached TPO installed over the existing EPDM after stone removal. The sequence: remove and haul ballast stone (typically 10-12 lbs per square foot over the full area — significant tonnage), inspect and probe the existing EPDM and all seams, pull moisture cores, document deck condition at inspection ports, then install mechanically-attached TPO with tapered insulation to current energy code and new flashing details at all perimeters, penetrations, and drains. The resulting system is a modern warranted roof with no ballast dead load and no ongoing stone-management operational concern.

Stone removal cost is a real factor in the economics. Hauling 10-12 lbs of stone per square foot off a 50,000 sq ft roof is roughly 600,000 lbs of material. This is a significant mobilization and disposal cost that has to be factored into the recover scope. We provide this cost itemized in the scope — it is not buried in the general labor rate.

Full replacement (stone removal, tear-off of existing EPDM and insulation, new assembly from deck up) is required when moisture cores show significant saturation, when deck inspection reveals corrosion or structural softening, or when the accumulated roof weight already exceeds structural limits. We do not recommend recovery on a saturated insulation assembly.

Have a ballasted roof on a Fort Worth commercial building?

We will assess the existing system, pull cores, document the deck, and give you a written recover-versus-replace recommendation — including stone removal and disposal cost in the scope.