Downtown Houston Church Revived

The Customer

A cornerstone for Houston’s faithful and historical societies, the 146-year-old Annunciation Catholic Church’s structural stability was being threatened by the flourishing city.

Located across from Minute Maid Park, Annunciation Catholic Church has rested at the center of downtown Houston for more than a century. In 1867, initial construction was funded by a single priest who purchased the old Harris County Courthouse, dismantled, and repurposed the bricks to build the church’s foundation. With no money to complete construction, the community took it upon themselves to raise money for the church. It was completed in 1873 and remains Houston’s oldest existing church.

Annunciation has watched the city of Houston grow from approx. 9,332 to 2,300,000 in population. Now, Houston is the nation’s 4th most populous city and recognized worldwide as the “Energy Capital of the World“. Unfortunately, growth and expansion doesn’t suit historical structures well. In 1997, due to severe structural problems and nearby construction the church’s century old Annunciation School was demolished. Annunciation Catholic Church was deemed a Texas Historical Landmark in 1969, so demolition seems unlikely, however when structural issues arise a gentle hand is needed to carefully make repairs.

The Challenge

Through years of nearby construction and drainage fluctuations, Annunciation’s foundation took a hit. A large void had developed underneath the church’s southwest corner and, symptomatically, the foundation subsided. Having dealt with lengthy and disruptive repairs in the past, Annunciation wasn’t keen to go through the process again, however after learning about The URETEK Method® and having been vouched for by engineers they were willing to proceed.

The Solution

The URETEK Method® is a polymer injection process that utilizes URETEK’s patented structural-grade, expanding polymer. It is applied through injection sites below foundations or concrete structures where, through polymer injection, expands to simultaneously fill void space, stabilize soil, and lift subsiding foundations or concrete slabs. The URETEK Method® is a cleaner, longer lasting alternative to interior pilings and slurry pumping.


Technicians began work at the church by drilling multiple 5/8” holes (penny-sized holes) through the southwest corner’s affected area. URETEK polymer was then injected at low pressure below the slab. Within seconds of being injected the polymer starts expanding and filling voids. During expansion the soil is gently compacted and a dense aggregate of existing soil and polymer is formed. URETEK’s highly-skilled and experienced technicians monitor injections with computer and digital levels. Once voids were filled and the soil had reached its refusal point, the expanding polymer surgically (and carefully) lifted the church’s foundation. The process continued at each injection site until the voids were filled, stabilized, and the foundation had been brought to acceptable elevations.

Work at Annunciation Catholic Church was completed in two days with minimal disruption to mass and parishioners. In fact, because The URETEK Method® requires minimal to no excavation to achieve the results desired, technicians would clean and vacate the area before Mass then continue work after the congregation had dispersed—a unique benefit URETEK offers which is unmatched by other repair methods.