How well does Permeable Interlocking Pavement drain in Houston, TX? The data speaks volumes
Western Academy, a private liberal arts school for boys, grades 3-8 and located in the Spring Branch Area of Houston, Texas, as of mid-August, 2022, has breathable pavement that will help keep their 200 year old oak tree healthy. Western Academy also has benchmark infiltration rate data that reflects their investment’s actual permeability.
Permeable Interlocking Concrete Pavement (PICP) is recommended as green infrastructure by The City of Houston. The PICP could have been taken right up to the trunk of the oak, however, the property owners were reluctant to take even the slightest risk of possibly harming the oak.
The pre-PICP pedestrian surfaces consisted of wood decking in one area and a concrete slab under the pavilion area. The wood decking was scheduled for maintenance or replacement. Both materials were kept at a 30 foot radius away from the old oak to allow air penetration and lessen any burden over the oak’s root system. Western Academy’s vision was to have a single, minimal maintenance and safe surface for the feet of their students. The life cycle costs of replacing wood made the more durable PICP even more appealing.
Belgard’s Eco Dublin in the Rustic Beige color, pictured below, was the permeable product selected to enhance the integrity, safety and beauty of this prestigious academy’s pavement and proved to be quite a contrast to the previous materials. The permeable pavement’s installer is Pro Pavers Houston, LLC.
Why was this PICP system tested for its infiltration rate? Even Belgard, the product’s manufacturer, claims their Eco Dublin is permeable. The answer lies in the entire system. The Eco Dublin is just one component of the permeable pavement system. The system was tested to learn the day of installation infiltration rate of the system, which also includes free draining aggregates underneath the permeable pavers. The free draining aggregates allows rain fall to percolate through it instead of allowing the rainfall to run off its surface. The PICP was also tested to collect a benchmark of how fast water passed through the system. These data can be collected periodically to learn whether the system loses some permeability, and if so, how much. Should the system lose a sufficient amount of permeability, then, the system can be vacuumed to restore more permeability.
For the start of this case study, ENOCH GROUP Data, LLC, performed the infiltration rate testing to establish a benchmark rate for the new installation. The procedure included the placement of a specified sized ring atop the permeable pavement’s surface. The test ring was secured from leaking, a specified weight of water was poured into the test ring at a specified level and the pour was timed. A pre-wetting test was carried out first at each of the three testing locations to determine which weight of water would be used at each location.
Infiltration rate data collection method was discussed with Western Academy Headmaster, Justin Hebert. The actual procedure was observed by Belgard Commercial Sales Representative, Avery Terry, and Techniseal Regional Sales Manager, Matthew Utz, as data was collected at three different areas throughout the new installation. Mrs. Terry expressed interest in the possibility of Belgard considering ENOCH GROUP Data, LLC, as an independent, third party entity to provide infiltration rate testing on various permeable pavement installations incorporating their permeable product line. Mr. Utz expressed interest in the possibility of having independent infiltration testing of some of Techniseal’s paver jointing products.
The test data were taken to ENOCH GROUP Data, LLC’s office where the infiltration rate was calculated to be a site average of 966 inches of rainfall per hour. This benchmark infiltration rate is why, The City of Houston, has recommended Permeable Interlocking Pavement systems as green infrastructure. Western Academy has now served as a role model for other property owners to get on board by utilizing this aesthetically pleasing and environmentally logical pavement system.
Pictured below are the PICP collected data and infiltration rate report for Western Academy on August 17, 2022.
For more information on Pro Pavers Houston’s hardscape installation services, please visit Pro Pavers
For more information on Belgard hardscaping products, please visit Belgard.com
For more information on Techniseal hardscape protectants, please visit Techniseal.com
For more information on ENOCH GROUP Data, please visit ENOCH GROUP Data
