To my friends, colleagues, and clients thinking about installing porous concrete to keep the impervious ratio down and comply with best water practices… Please beware!
I installed porous concrete, in 2013, on a lot for which I also did the snow plowing; I was therefore able to ensure that no salt was ever used and that snowplowing was always done with a rubber-edged plow blade.
During the winter of 2013/2014 there was a tremendous amount of salt used to keep ice off the roadways but, of course, we used absolutely none on this lot. Even so, THAT salt destroyed 30+ parking stalls on which porous concrete was used.
The concrete company, who was the selling factor to train and install this material, did not warranty any of the concrete and, unfortunately, in 2015, I had to remove all the porous concrete material and install porous pavers to keep the site’s impervious ratio within the town’s limits. The pavers worked out better than expected but were very expensive.
So what went wrong? What I found, and what the concrete company, and the concrete industry in general, did not know, or did not want to share, is that when cars drive on salted roadways, the salt builds up behind their tires. When those cars park on porous concrete surfaces during the day time, the salt clumps fall off and start to destroy the porous concrete.
I think porous concrete is a good fit for climates that do not need to use much salt to keep roadways, walkways, and pedestrian hard surface areas clear of snow and ice; but, in New Jersey and other cold climate areas, it is just a waste of time, effort, and money.
If you have questions, would like to discuss further, or have a project for which we can help, please feel free to contact me (908-797-2305).