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By Bruce H. Soileau, Consultant to Pavestone Company

Interlocking pavers define the space used for games such as checkers by the elementary students. Project designers determined using interlocking pavers would be the best choice for designing patterns in the courtyard.
Images courtesy of Pavestone Company

Andrew H. Wilson Charter School was one of the many schools hit hard by Hurricane Katrina in August of 2005. Local architect E. A. Christy designed the original school building in 1909. Nearly 100 years later, during Hurricane Katrina, the school received approximately two feet of water on the first floor and sustained substantial roof damage.

The heavy damage from the storm and deferred maintenance qualified Andrew Wilson School to be chosen as one of five Quick Start Schools for the New Orleans Recovery School District.

Permeable interlocking pavers proved to be an attractive and functional drainage solution for the designers. When heavy rains flooded that area of the city shortly after the installation of the permeable pavers, the Wilson campus courtyard drained perfectly.

Play Area
HMS Architects, a New Orleans architectural firm, was picked to design the new school building. Part of the design included a new courtyard or playground for the children. The original goal for the courtyard was to have a system in place that would clean the water and recharge the soil. A 12,000-gallon rainwater collection tank with underground percolation systems and detention areas was installed to help reduce rainwater run-off.

The architects originally considered permeable asphalt paving, but since none of their team had worked with it before, they decided to go with an innovative and proven technology…permeable interlocking pavers. Long-term design life was a concern. According to research, permeable pavers last up to three times that of asphalt paving. The decision was made to proceed with permeable pavers.

Charles B. Montgomery, AIA, ASLA, Principal of HMS Architects, said, “we evaluated how we could define the space for various activities for elementary students, such as checkers and various games, then decided that the interlocking pavers were a better choice for designing patterns into the courtyard. The design team felt it needed to activate the space by giving it some patterns so it did not seem so monumental. It is attractive to look at when empty, but when the kids are playing on it the courtyard comes alive.”

A 12,000-gallon rainwater collection tank with underground percolation systems and detention areas was installed to help reduce rainwater run-off.

Installing the Pavers
Castle Rock Pavers was contracted to install just over 9,000 square feet of permeable pavers for the courtyard. Susanne Drygalla, owner of Castle Rock, immediately saw that this project required a good drainage solution.

Drygalla explained, “There was a big school courtyard that they wanted to pave entirely except for four planters that were installed. When you get these gigantic four inch per hour rains like you get in Louisiana, there was no way they could drain it using typical interlocking concrete pavers. The paved area carried not only surface drainage from the surrounding site but also had downspouts from the roof discharging storm water as well.” This additional discharge added to the drainage issues and the area did not have enough fall to effectively drain. By installing Pavestone’s Eco-Priora™ permeable pavement and the additional swales, the drainage problem was resolved.

There were some very steep slopes that made grading the project very difficult in areas, but the contractor was successful in obtaining the required results.

When heavy rains flooded that area of the city shortly after the installation of the permeable pavers, the Wilson campus courtyard drained perfectly. This assured everyone involved that the permeable paver solution was the right choice. The whole area around the school was flooded, but their courtyard had no flooding problems whatsoever.

HMS Architects, a New Orleans architectural firm, was picked to design the new Andrew H. Wilson Charter School building and playground. The original school building, built in 1909, was heavily damaged during Hurricane Katrina.

Material Specifications Matter
When asked what advice she would give when bidding on a permeable paving job, Drygalla replied, “When you get a job, get the initial specifications and visit the site with the architect. Always remember that we live in the land of Murphy’s Law. What can go wrong will go wrong, so just try to preempt it by doing your homework concerning the project specifications.” Susanne Drygalla recommends visiting the jobsite in person with the architect well in advance of any work being done, so you can properly access the drainage situation, which is critical on a project such as this.

Study what materials are being specified for the project, and make sure that these materials will work for the particular jobsite area. Architects and contractors must anticipate potential problems ahead of time to be certain that the project remains on schedule once started. These types of projects are more likely to have issues that could have been prevented with a site visit before the bid submittal. In an economy where price is a big factor and the lowest bid gets the contract, a contactor must be confident that all potential issues are covered in the bid.

The A.H. Wilson School project was designed to be both functional and aesthetic. There are checker boards made out of pavers and other games for the kids to play on. Even though it is a drainage application, you still have all of these pretty designs with pavers. It shows that functionality and attractiveness do not oppose each other. This was a decorative paving job that turned into a drainage application – all of which was still attractive.

Andrew H. Wilson Charter School was awarded LEED Gold Certification by United States Green Building Council that includes 40 specific green measures to minimize electricity and energy usage by enhancing natural light and allowing for efficient heating and cooling strategies, as well as reducing water run-off which was achieved from the use of a permeable paving system.