Cool pavements are materials that either reflect solar energy or are porous, meaning water can pass through to the soil below. Pavements with a high solar reflectance are cooler to the touch and store less heat than conventional pavements.
Porous or permeable pavements have the ability to store and evaporate water, cooling the pavement and the surrounding air.
Conventional Pavement
Paved surfaces cover as much as 29-45% of total urban surface area, and contribute to heating up cities and neighbourhoods.
Anyone who’s ever walked barefoot on a conventional pavement knows just how hot it can get. Asphalt absorbs most of the solar energy that reaches it and heats up, becoming very on warm sunny days and reradiating heat to the atmosphere in the evenings. Concrete is a lighter surface, but darkens and gets hotter over time from the buildup of tire residue, dirt and oil.
Neither asphalt nor concrete allows rainwater to be absorbed and cool the area. Similarly, interlocking pavers installed on top of limestone screenings or other materials that reduce drainage will contribute to a hotter environment.
Types of Cool Pavement
There are a number of paving materials and systems that can be used as cool pavements.
Asphalt and concrete pavements can be cooled by adding light pigment, lighter-coloured aggregates, sand or binders, increasing the solar reflectance.
Permeable pavements contain void spaces that allow water to pass through to sublayers and the ground 
below. Examples of permeable pavements include porous pavement, permeable block pavers and open cell paving systems. These pavements use varying materials to increase permeability and allow water to pass through and cool the surrounding air.
Why Use Cool Pavement?
Cool pavements offer many benefits to homeowners. In addition to creating cooler air temperatures, reducing cooling energy use and peak energy demand, cool pavements have the ability to reduce stormwater runoff and flood risks and also have a longer life span than traditional pavements.
There are no official labeling programs to designate cool paving materials in Canada, therefore homeowners should consider the cooling properties of paving materials when selecting a paving product.
Contact us for more information on how to select a cool paving product for your home.
