Poured concrete

Just like CMUs, this type of foundation has been around for decades. Poured concrete foundations are made by pouring wet concrete mixture between large plywood forms held together by metal or plastic ties. The wooden forms are peeled away when the concrete has dried.

“Poured concrete is one of the most cost-effective and reliable type of foundation, best suited for soil conditions and the tough environment in Canada,” says Octavio da Silva, owner of Modernized Building Group, a Toronto-based framing and foundation company.

He says many custom builders prefer poured concrete because of its ability to support heavy vertical loads and strength standing up to lateral ground and hydro- static pressure.

“When properly built and given the required time to cure before back filling, they can last 100 years,” says da Silva.
Most poured concrete foundations are 8” in thickness. Reinforcement bars
are used to prevent cracking and bow- ing. Unlike CMU foundations, poured concrete foundations do not have joints that could be sources of leaks or become weak points.

Environmental conditions on the job- site can impact the quality of the concrete mix. For instance, if the concrete sets and cures too fast or freezes, this may cause cracking. If the mix is too wet due to improper mixing or rain at the time of construction, the foundation may become weak.

Another disadvantage is that poured concrete foundations are heavier that CMUs and may settle considerably over time even with proper footings.