The Fred C. and Katherine B. Andersen Building expands the Mayo Clinic Proton Beam Therapy program into a new 110,000-square-foot, $200 million building. Located in Rochester, MN, the new, larger facility will feature two new treatment rooms, in addition to the four treatment rooms currently in operation and it will offer improved access for patients requiring proton therapy. When the new building is operational, the clinic anticipates it can treat an additional 900 patients per year with this technologically cutting-edge cancer treatment.
The site, located in downtown Rochester, would of course have its challenges once the colder weather set in, but there was a more immediate concern: The building foundation was below the water table. Initially, the project was specified for a hot rubberized asphalt waterproofing membrane over mud slab at the lower level under slab. Due to the nature of the hydrostatic conditions, however, this was not an ideal solution. The team had to pivot, and the applicator chose to submit EPRO’s PreTak Hydrolap as a suitable solution.
“The product substitution turned out to benefit the team and the project greatly,” said RAM Construction Services, Inc. the EPRO Installer. “We found PreTak easy and quick to install, which meant we stayed on schedule.”
PreTak is a pre-applied high-density polyethylene (HDPE) sheet waterproofing membrane combined with a pressure sensitive adhesive that fully adheres to cast in place concrete and shotcrete to prevent lateral water migration in both blindside shoring and underslab applications. Installation is productive and reliable with up to 8 ft wide rolls to minimize seams.
The system was installed during the less desirable Minnesota fall and winter season, and it stood up to the challenge. PreTak’s dual factory-adhered Hydrolap selvedge seams feature a specially formulated adhesive for superior seam adhesion, which can be applied even in environmentally challenging, cold or wet conditions.
“PreTak was easy to apply even in the winter, which helped us out,” said RAM Construction Services of Minnesota. “Waterproofing materials can be more challenging to install in cold weather conditions, but with PreTak we were able to get the job done efficiently – which was much appreciated!”
Since this project was an addition to an existing structure, the PreTak system also had to tie into the existing adjacent building and tunnel structures. Here, the system connected existing self-adhered waterproofing membrane which further demonstrates PreTak’s adaptability.
“Joining different waterproofing systems can be complicated with, at times, difficult transitions or terminations,” said RAM Construction Services of Minnesota. “We were able to coordinate the PreTak tie in with no issues.”