Frequently Asked Questions
+ Is it really concrete?
Yes, it is.
Pervious concrete is made with aggregate (rocks), portland cement and water, just like regular concrete. By leaving out the fine aggregate/sand and making very specific changes in the mix proportions, we are able to create a large quantity (approx. 20%) of interconnected voids. Compressive strengths are generally in the 3,000 psi range.
+ Where would pervious concrete be used?
Pervious concrete can be used in the place of conventional exterior pavements for parking lots, roads, driveways, walkways, sidewalks, paths, courtyards, and sports courts. It is suitable for light to heavy vehicle traffic at low to moderate speeds - including buses, fire trucks and semis.
+ My site has clay soils; will pervious concrete work?
Yes! Using site-specific soil infiltration rates the pervious concrete system can be designed to compensate for slow draining soils. We have modeled and installed systems on everything from sandy based soils to the clay Type D soils found commonly in the Bay Area. From the first flush to capturing all the impervious cover runoff, we can plan, model, and install a system that captures and infiltrates all your stormwater without the need for a conventional stormwater infrastructure. Contact us about our design consultation services.
+ What is the expected lifespan of pervious concrete?
Same as traditional concrete, 30-50 years.
+ Won't it clog? What about maintenance?
A little bit of common sense site design can go a long way towards avoiding any clogging issues. Runoff from adjacent areas laden with sediment should not be directed onto the pervious. Short of that normal debris from traffic, trees and people have little effect on the ability of pervious to drain water. A high quality installation will allow for 500-1500 inches of water to pass through per hour, even if it was 95% clogged it would still allow 25-75 inches of water to pass through per hour. That's more water than even the largest storm event. Check out our videos to see some pervious installations in action. Most high quality pervious concrete installations will need minimal maintenance. If the surface should ever clog, cleaning with a power washer and/or a vacuum truck will restore the pervious to its original state. More information can be found on our blog posts regarding maintenance, as well as our maintenance booklet available on our resources page.
One additional thing to note is that the only substances that can truly clog up pervious concrete installations are chewing gum and asphalt fines, small debris that sheds from asphalt pavement. These asphalt fines get into the air pockets of the pervious concrete, when the surface warms up from the sun they melt, sealing the air pocket, and becoming impossible to remove. Even the strongest vacuum truck will not get them unstuck. We never recommend that pervious concrete be installed adjacent to asphalt without a buffer, as the encroachment of clogging asphalt fines is permanent.
+ What if the rain is coming down faster than the water can absorb into the soil?
The layer of drain rock beneath the pervious concrete acts as a detention area, or buffer, to hold water until it has a chance to soak in. The thickness of this base layer will vary according to your particular site and project requirements. If you would like more information on how we can help you design your pavement for optimum performance, contact us about our consultation services.
+ Is it ADA compliant?
Yes. Pervious concrete meets ADA requirements for both smoothness and flatness.
+ Can it be made in different colors and finishes?
Yes! Bay Area Pervious Concrete is the only pervious concrete installer in Northern California to develop different aesthetic finishes for pervious concrete. We welcome you to look at the variety of finishes we offer on our finishes page. We can also work with clients to create a custom look for their project using a variety of colors, aggregates and finishing techniques. If you have specific questions about colors, aggregates or finishes please contact us.
+ What services do you offer?
Installing and Sub-contracting
Led by NRMCA Craftsman, David Liguori, we have a team of specially trained installers who are experienced in working with our proprietary mix designs to install and finish our pervious concrete to spec. We have installed small to large-scale projects for commercial, residential and municipal clients all around the California Bay Area. Let us know if you would like to see some reference jobs and photos of our work. Contact us for a free estimate for your new pervious installation.
We specialize in providing consultation on stormwater management systems design, pervious concrete specification development, engineering documentation, and on-site infiltration rate testing. Our consulting fees can run per hour, or per project. Contact us for a free estimate of the consulting fee.
Knowledge is power, and we want to empower you to take your stormwater design to the next level. Our presentation will walk you through the design principle behind LATIS, and show you how to maximize your design and minimize your costs while meeting stormwater regulations, without sacrificing site design. We typically present for 45 minutes and take questions for another 15-20 minutes. Please contact us to schedule a presentation for your office or organization.
+ Is it installed the same way as traditional concrete is installed?
No, not at all.
The unique properties that allow water to pass through pervious concrete also make it behave quite different during transport, installation and curing. In fact, we do not even use the same tools used in traditional concrete. The ideal method of installation is with a very specialized piece of equipment called a hydraulic roller screed. No other method can match the level of compaction, density and finish.
In terms of mix design, installation technique and timing, the window of tolerance for a successful installation is very narrow. The failure rate for pervious concrete installations by inexperienced and non-certified contractors is over 70%. When it comes to pervious concrete there is no room to guess. If it goes poorly there will be a very unsatisfied client that may insist that the work be torn out and done again.
Due to the specialized nature of pervious concrete all our staff have been highly trained. David Liguori is the Bay Area's only NRMCA Certified Craftsman and has years of expertise delivering superior results. Our team has designed and installed nearly a half a million square feet of pervious concrete all around the Bay Area. Read more about our stellar team.
+ How do I know if my installer is qualified? Is there a certification for Pervious Concrete?
Yes, there is a certification, and it is important that you verify your installer is certified to ensure he has the education and training to do the job right. The National Ready Mix Concrete Association (NRMCA) is the certifying body. NRMCA issues a certificate of qualification to each individual who qualifies, be sure and ask your installer to see his certificate. Ours are here. In addition, ALWAYS ask for references (several) and go see the installations for yourself. Contact us to get a list of our reference jobs.
Although it technically is concrete, pervious concrete has unique properties that cause it to behave very differently. As such it requires a completely different set of skills and knowledge that can only be acquired through completion of the certification program and hands on experience with the product.
+ Is Bay Area Pervious Concrete an installation expert?
We, at Bay Area Pervious Concrete, have a trained and certified crew, including the Bay Area's only Certified Pervious Concrete Craftsman, that have designed and installed nearly half a million square feet of pervious concrete all around the Bay Area. We would be happy to give you a list of our reference work so you can go and see what professionally installed pervious concrete looks like. Please check out photos of our work and current blogs to see some of our recent projects.
We are happy to sub-contract pervious concrete work from you, and as a contractor you can do much of the prep. Please contact us if you would like us to bid a project for you.
+ Are there any rebates available for pervious concrete?
Yes, but only in limited areas at the moment. If you know of a rebate we are missing please contact us and we will make sure to update our list.
City of Palo Alto Stormwater Rebate: $1.50 per sq/ft of permeable pavement up to $1,000 for single-family residential, and up to $10,000 for multi-family and commercial projects. You will also need a to submit a drawing with project details. Download the rebate application.
Scotts Valley Water District Lawn Replacement rebate: $1.00 per sq/ft of replaced lawn, up to $2500 per project site.You will need to schedule a pre- and post inspection of the project site. Download the rebate application.
Bay Area Water Supply and Conservation Agency Lawn Replacement Rebate: $1.00 - 4.00 per sq/ft of replaced lawn. Available to single family and multi family residential, commercial, industrial or institutional customers. You will need to schedule a pre- and post inspection of the project site. Up to 50% of the landscaping can be pervious concrete, the other 50% must be plants. Must be a customer of one of the participating BAWSCA agencies. Download the rebate application.
+ Are there any community or institutional grant programs for pervious concrete?
Yes! San Francisco Public Utilities and the City of San Francisco offers Urban Watershed Stewardship Grants, as a part of the Community Challenge Grant Program. The grants support the planning, design, and construction of green stormwater management facilities - including pervious concrete! Grants are available to non-profits, neighborhood groups, and schools within San Francisco. Project award sizes range from $15,001 to $100,000; there are fund matching requirements of 25-35% depending on the size of the project. Download the Community Challenge Grant Program forms.
+ What if I have a question not listed here?
Please contact us and ask! We are happy to answer your questions.