During the hot summer months, the last thing on everyone’s mind right now is snow. If you are in the construction industry, however, cold weather is definitely impacting your life. Permeability and frost are a concern for builders year round as they plan their projects. Things need to start either before the frost sets in or in spring when the ground thaws. It can be a real scheduling nightmare.
And then there’s what comes after. After a wet and cold winter, cities are filled with road work as pavers are working around the clock to repair the potholes and uneven ground that was caused by the erosion that salt causes to the pavement.
Why all this ‘re-construction’? When the spring comes and snow melts, due to non-permeable surfaces, the water has nowhere to run off. This results in an increase in flooding, as well as a shifting in pavement, sidewalks, hiking trails and other surfaces used for transport.
There is a simple solution: permeable paving methods. This alternative method has been proven to reduce the amount of repair needed to roadways, trails and the like by allowing the water to go through the roadways, instead of running off the sides.
Let’s take a look at what this looks like for one Toronto College.
With temperatures as low as -40 degree celsuis, snow and ice were commonplace at George Brown College. That meant salting the parking lot (as well as lots of shovelling). This year, they installed Ecoraster in their lots. And now? No salting required!
What is the science behind this?
Since the water runoff from the snow disappates through Ecoraster’s permeable paving, there’s no pooling or freezing of water. It allows the natural surface to ‘breathe’, and act as a natural insulator rendering salt and sand redundant. Kortright Centre in North Toronto found the same thing. Operational staff found that the permeable pavers did not require salting to the degree needed with conventional paving methods over the winter months.
In fact, The University of Guelph conducted a three year study to assess the benefits of using permeable pavers in the cold Ontario climate and geologic conditions of the area. This geological area is an exceptional region study since the native soil is naturally less permeable there, due the rocky shale elements below the surface. Here, the installed permeable pavers were exposed to a critically cold climate, resulting in a highly accurate comparison of the effectiveness of the surfaces in clearing away snow and ice.
The clear winner? Ecoraster’s permeable paving.
Their study findings reported that permeable pavers “offer significant benefits for the treatment and management of stormwater over conventional asphalt-to-catchbasin collection systems.”
One advantage to using a permeable alternative was the “capacity of these systems to reduce outflow volumes even when applied to areas with low permeability soils.” Up to 7mm of rainfall was captured by this alternative method, mitigating adverse effects that are currently exposing urban landscapes using conventional methods. In urban centres where permeable solutions are used, the volume of stormwater outflow infiltrates and evaporates when hitting the surface, reducing the risk of pooling water, flooding, and the build up of dangerous icy conditions in cold winter months.
In March 2011, Southern Ontario experienced a substantial spring thaw. Findings from the elevation surveys reported that the freezing temperatures experienced in the area “did not cause significant surface heaving or slumping…the permeable pavers delayed the outflow of melt water by three days and greatly reduced peak flows.”
While planning construction projects around the cold and frost may still be necessary to some extent, you can give yourself more scheduling freedom by using a permeable paving solution. This way to address water run-off can simplify your project management, as well as being more cost-effective.
*Quotations taken from KPP-FINAL-2012 UNIVERSITY OF GUELPH, TORONTO AND REGION CONSERVATION (Jennifer Drake and Andrea Bradford, University of Guelph, School of Engineering and Tim Van Seters and Glenn MacMillan, Toronto and Region Conservation December 2012 © Toronto