Parking Structure & Deck Waterproofing in San Antonio, TX

A parking garage is not a roofing problem in the conventional sense - it is a horizontal concrete structure that cars drive on, and the waterproofing has to survive tires, turning loads, and 165°F surface temperatures on the exposed top deck. San Antonio's structured parking inventory is concentrated where land is expensive: the downtown core around the River Walk and Henry B. González Convention Center, the South Texas Medical Center's hospital and clinic garages, San Antonio International Airport, and the office clusters along Loop 410. Most of it is post-tensioned concrete, which raises the stakes considerably. Water that reaches a post-tensioning tendon corrodes high-strength steel under load, and a failed tendon is a structural repair measured in six figures - not a maintenance line item.

The attack sequence is predictable. Water enters through cracked topping slabs, failed expansion joints, and cove joints at walls and columns, carrying whatever chlorides it picks up along the way. San Antonio does not salt roads the way northern cities do, but chlorides still arrive - in irrigation overspray, in the occasional ice event, and in the concrete mix itself on older structures. Once chloride concentration at the rebar passes threshold, corrosion starts, the steel expands, and the concrete spalls from the inside out. You see it first as ceiling delamination on the level below, rust staining at cracks, and efflorescence trails under the joints. By the time chunks are falling on parked cars, the repair scope has typically tripled.

Our scope work separates the three layers of the problem. First, structural condition: chain-drag sounding for delamination, crack mapping, and a hard look at every expansion joint gland and nosing. Second, the waterproofing system itself: exposed top decks get UV-stable polyurethane vehicular traffic coatings with aggregate in the wear course, while covered intermediate decks can often run a lighter base-and-wear build since they escape direct sun. Third, water management - slope, drains, and scuppers, because a traffic coating ponded under three inches of water after a spring storm will fail years early. We phase the work by bay and by level with striped lane closures, so a 600-space Medical Center garage never loses more than a fraction of its capacity while we recoat.