Poured Concrete Foundation Repair

How to recognize a Poured Foundation

A poured foundation is a type of foundation made from solid concrete that is poured in place. It has become the most common type of home foundation since the mid-1970s. A poured foundation is easily recognized by its relatively smooth surface. This type of foundation is effective at resisting water pressure from the outside, which helps protect your home against leaks. Additionally, it is relatively easy to waterproof, as it consists of a single solid material.

Knowing the age of your foundation

Generally speaking, there are two types of poured foundations.

The first type includes homes built around the turn of the century, where the foundations were formed using wooden boards, and the concrete was mixed and poured on-site. This concrete was typically of low quality, often with stones found on-site added to the mix. Some people mistakenly refer to this type of foundation as “rubble.” Most homes in the Ottawa area built before the 1940s likely feature this type of construction.

The second type consists of newer poured foundations, commonly found in homes built after the 1930s. These foundations were also formed with planks and boards, but the concrete mix was of much higher quality. It wasn’t until the 1960s that more modern forms and ties were introduced.

Now, let’s address these two types of poured foundations separately, along with the different issues they may present.

Turn of the Century Poured Foundations (1900-1940s)

Many of these homes had little or no damp proofing, or it was completely washed away. Damp proofing is the most basic form of foundation protection against water, and it does little to prevent moisture from entering the concrete. Aside from the obvious issues of water damage in your basement, such as mold and mildew, damp walls that freeze can lead to concrete damage. The freeze/thaw cycle can cause the concrete to break down, resulting in a condition known as spalling. This issue is particularly common due to the poor quality of concrete used in homes built at the turn of the century. Additionally, the absence of drain tiles (also known as weeping tiles) exacerbates the problem by preventing water from draining away from the foundation.

Poured Foundations (1940 – present)

The poured foundations often show damage from freezing, where the concrete can disintegrate into dust. However, this issue is less common with higher-quality concrete. Water and moisture problems, including mold and mildew, remain significant concerns. Drainage tiles (also known as weeping tiles) are typically present, but older clay tiles are often blocked with soil or clay and may be broken. Plastic drain pipes became standard in the 1970s but did not include a filter sock until the 1990s. As a result, these plastic pipes can also become clogged.