PICP: More on Cold Climates
Updated: Apr 20, 2020
After what might be this season’s heaviest snowfall, I shall once again make an attempt to promote the fine winter advantages of PICP on my super popular blog.
We are reminded this year, following several mild winters, that we do, in fact, live in Minnesota, where half of the year people rarely complain, and then it gets cold and stays there for a very long time.
I was reminded of this fine topic via an email from my most recent permeable driveway client. “The driveway you installed in November looks and works great. I actually enjoy shoveling snow because it is so easy”. Typing this out I realize it sounds like an infomercial of PICP performance. However, I promise you it is real.
When I followed up with a phone call, my client went on to explain that he had noticed a stark difference between the pavers and his neighbor’s concrete driveway.
That is, no frozen slippery chunks left behind (his photo attached). He laughed when I told him that nearly all of my driveway costumers express some degree of concern about the potential difficulty of shoveling pavers.
I followed up this conversation with a bit of reading. And the actual factual part of it is: research done by such fine institutions as the University of Minnesota has shown that a PICP base does not get as cold as the air and wind above. Air in the spaces between the aggregate and heat from the earth retained in the soil below has been proven to thaw surface snow and ice more rapidly than traditional asphalt and concrete pavements. If any standing water within the open-graded base materials freezes it can expand 9% to prevent heaving.