Moisture is no stranger to the South. A hot day in July, combined with Louisiana humidity, makes it all the more challenging to keep moisture out of buildings. Like many cities in humid climates, Baton Rouge is taking a hard look at the need for quality waterproofing in its large-scale plans to improve the downtown business district.
Although the government office buildings in the central downtown area handle major issues every day, water intrusion was not one of them. The design and construction of the new office buildings involved a strong waterproofing defense system that allows the concrete to function without degradation.
One of the project’s newest buildings, the Iberville Building, located at the gateway of the Louisiana State Capitol building, required an immense amount of waterproofing. The building is part of the Capitol Complex Campus for the State of Louisiana, which houses statewide offices and includes 10 office buildings.
With the Mississippi just a short distance from the Iberville Building, extra measures were taken to keep waters at bay. Constant water pressure was not in the construction’s favor, and officials made plans to ensure that the building’s waterproofing integrity wouldn’t be an issue. “There used to be a 13-story building here,” said Don Brouillette, who has 25 years of below-grade waterproofing experience and is the owner of Don Brouillette and Associates in Baton Rouge. “We imploded the building and left the existing basement. We then began building the new basement inside the existing basement.”
With an average of over 60 inches of rainfall a year, the Iberville Building (which houses the department of social services), administrative buildings, and print facilities needed to be watertight. “It was like waterproofing a bathtub, but we wanted to keep the water out of the tub,” said Brouillette.
The concern of water intrusion in the 9-story building’s interior made specifications strict for this government project. “The state requires that we select two systems to keep the bid open,” say Michael Holly, Holly & Smith Architects Inc., an architectural firm in Hammond, LA. “Carlisle Coatings and Waterproofing’s (CCW’s) MiraCLAY membrane was chosen for this project for many reasons. We are familiar with the system and it has proven success[ful]. We like the involvement that CCW offers. It’s as though we have eyes watching over the project, making sure everything goes as planned.”
The MiraCLAY product is a bentonite clay waterproofing membrane that prevents water intrusion in below-grade applications. Its impermeable composition worked especially well for this project due to the product’s ability to endure hydration and it self-seals punctures or penetrations. With a variety of construction workers at the jobsite and rebar being installed, this was a major benefit for the job.
“It’s easier to install than other waterproofing systems. It’s like cutting butter,” says John Deare, a construction worker for Apex Waterproofing, New Orleans. “It’s very light compared to what we were working with.”
With the 278,902-square-foot project scheduled to finish in April 2006, the initial steps of installing the CCW MiraCLAY did not prolong the construction. The system’s uniform layer of sodium bentonite clay is between a durable puncture-resistant, non-woven polypropylene fabric and a high tensile-strength woven polypropylene fabric that allows it to endure construction wear and tear. “The MiraCLAY’s geotextile composition prevents it from deteriorating,” explains Brouillette. “It’s both durable and natural, two benefits that are hard to find in waterproofing products.”
Exceptionally durable and flexible, the fabric is needle-punched together with thousands of high strength denier yarns. Providing an integral water barrier, the fabric is then thermally fused to the polypropylene in a patented infrabond procedure that locks the sodium bentonite into place.
“We laid the MiraCLAY like a carpet,” said William Fey, a construction worker for Apex Waterproofing, who has worked in the construction industry for 23 years. “We are installing it with a 4- to 6-inch lap staggering seam. We then stapled the seams and placed rubber water stops in areas where there are penetrations. The system won’t allow any moisture to come from the ground into the basement.”
If the MiraCLAY is in a hydrated state, it offers tremendous impermeability and excellent resistance to most chemicals. One of its most impressive qualities is that it has the ability to heal itself if ripped or punctured. Environmentally friendly, it is non-toxic, non-polluting, and has no fumes.
The job was a little more challenging since the bentonite membrane was installed on top of the existing concrete slab. Massive amounts of rebar and MEP conduit were installed on top of it and finally the concrete was poured to cover all of these systems. “Due to extenuating circumstances such as the weather, the MiraCLAY product was exposed to the elements for extended periods of time, until the weather permitted us to make concrete pours,” says Stephan Dorsey, project manager with Baton Rouge, LA-based Milton J. Womack Inc., the general contractor for the project.“The product was not totally submerged in water and there was minimal foot traffic, so it was able to form an impermeable layer for the existing substrate and the new basement. It allowed us to be flexible without compromising the integrity of the waterproofing.”
To further eliminate the problem with ground water and water pressure, the building was designed to use a french drain system. The french drain was engineered to be on the outside walls of the basement. The system was perforated and wrapped in filtration cloth that drained the water and was then pumped away from the building. The system relieved hydrostatic pressure caused by the ground water.
Not only was the waterproofing system effective, it was also very cost efficient. “There was definite cost savings with the waterproofing,” says Brett Laurent, president of Apex Waterproofing. “We also have a great working relationship with CCW; customer support is necessary for every job.”
And with below-grade applications it’s always essential to use products that work specifically well for a unique job. “The MiraCLAY is versatile,” explains Brouillette. “It is adaptable to a variety of situations. It can be easily adjusted, depending on the situation. Below-grade applications are different than other types of application. It is hard to tell what situations you may be faced with until you start digging. You want a product that can offer the kind of flexibility that allows it to function effectively, no matter the complexity of the job.”