Rush Oak Park Hospital in Oak Park, Illinois was experiencing significant damage due to a long-term water problem in an underground unit of the hospital. The unit had been leaking for nearly 20 years, and the extensive damage had rendered the area unusable costing the hospital valuable tenant space.

 

The cause of the leak was found to be improper below grade waterproofing. The waterproofing system that was installed included a “loose laid” sheet membrane, not a fully bonded membrane as called for in the original designs for the unit. Deficiencies were found in the sheet membrane such as open seams, splits and cuts. Once the sheet membrane was breached, water traveled under the membrane to any crack or opening in the structural slab allowing the water to leak into the building. In addition, the existing drainage board that was designed to funnel water away from the unit was clogged with clay prohibiting it from functioning properly.

 

In order to stop the leak and effectively prevent future problems, the entire plaza area needed to be excavated to remove the existing membrane and replace it with a new fully adhered, liquid applied waterproofing membrane system.

 

Considering the magnitude of the project, hospital management selected the PREMIER Engineered Projects delivery method to complete the work. Premier Engineered Projects combines engineering expertise and Construction Services Group (CSG) capabilities as a design/build delivery.

 

The unit was located directly below the Emergency Room entrance. To complete the construction, the entire parking lot and drive needed to be excavated, requiring the entrance to be at least partially closed to the public. The hospital had a tenant eager rent the space, so management decided to close the Emergency Room entrance completely and re-route traffic around the site giving CSG full access to the area. The team had 45 days to complete the project. CSG worked seamlessly with StructureTec to complete the construction plans according to schedule.

 

Because winter was approaching, CSG worked day and night in order to keep the project moving. Once the lot was excavated and the below grade substrate was exposed, a new fully adhered, liquid applied waterproofing membrane system was installed. CSG also installed a new drain system to effectively route water away from the structure. When it came time to replace the overburden, temperatures dropped too low to finish the project with asphalt. The team worked closely with the engineers at StructureTec to adjust the plans and use concrete. To ensure that the concrete cured properly, the crew brought in Glycol heating blankets to keep the ground thawed and poured the concrete one section at a time. CSG also worked with hospital management to redesign the parking area above. The redesign was not part of the initial plans, but it made the space more usable to hospital traffic by adding parking spaces and expanding the Emergency Room drive increasing the hospitals ROI.

 

CSG met and exceeded their client’s expectations by completing the project on time, under budget and adding features to the parking area above. The new waterproofing system installed by CSG is best-in-class, allowing the hospital to enjoy a leak free unit for decades to come. Selecting the Premier Engineered Projects option allowed the project to be fast tracked, quickly giving the hospital use of the unit to begin to generate income.