Should I Worry About Cracks In My Foundation Floor?

Cracks are a common feature in most homes, especially here in Toronto where you have older homes with foundations that are decades old. There are many things that can cause cracks to appear, from poor initial workmanship, to a shifting of the foundation itself. Cracks can be harmless or can mean serious trouble, what you need to find out is what’s causing the cracks in the first place. Once cracks form in the foundation, water is usually soon to follow. Many places in Toronto sit on top of high water tables, which can cause waterproofing issues in your basement.

The good news is that foundation floors are seldom structural. That’s because they are concrete poured in between foundation work. There are two reasons why cracks may develop in this. These are:

The earth beneath them was inadequately compacted before the concrete pour, and gave a little under the extra weight, causing uneven support for the foundation.
The concrete cracked because that is what large concrete areas generally do as they dry out. Some builders keep concrete flooring moist for longer periods of time to avoid this.
Hence your cracked concrete basement floor is not something you need to fret about for safety’s sake but can also cause water issues. Or is it perhaps? Read on and discover things you may not know.

Gas Intrusion
Undetectable methane and radon gas accumulates in pockets underground which are seldom tested during surveys. Sometimes a builder may disturb one and cause the gases to gradually escape. While the foundation work is supposed to keep them harmless a cracked basement floor manifestly cannot. Methane gas is violently explosive. Radon gas is the most potent cause of lung cancer after cigarettes.

Insect Infestation
Concrete floor cracks are perfect breeding places for ant and termites, from where they can fan out everywhere in your home. Tackling them upstairs is hardly the right place to start when they’re reproducing themselves constantly in the floor below. In extreme cases wide cracks can even harbor snakes. Thankfully, this is uncommon, especially here in Toronto.

Damp and Mold
There’s always moisture underground. That’s where rainwater naturally ends up, and after that can go almost anywhere. The force of gravity pressing down on the earth above makes ground water surprisingly intrusive. If you ignore non-structural floor cracks, don’t be surprised to find water bubbling up through them after heavy rain. If your home sits on a high water table, cracks can be an open invitation for a wet basement.

This problem is especially serious in basements underground. That’s because we seldom go down there to inspect. Damp conditions below the earth’s surface are perfect conditions for moss and mold to grow. Especially if the room’s kept tightly closed, and there’s no exchange of fresh air.

Fixing Foundation Floor Cracks
Like most things in life, there’s a right way and a wrong way to seal floor foundation cracks. The wrong way is to conceal the problem with surface filler. The better way is to pour in a polymer compound that forms a bond with both concrete sections. Best of all for wider cracks is to use an epoxy filler to recreate the original monolithic pour. However the stuff is expensive and you may need a concrete flooring specialist with experience and the right injection tools.