When your concrete foundation begins to flake and crumble away, it's a condition known as spalling. A spalling foundation needs to be remedied as soon as possible since it starts out as cosmetic damage and progresses until it threatens the stability of your home's foundation. Spalling is normally caused by water intrusion over a long period of time, so you'll need to improve drainage around the foundation along with repairing the damage. To learn more about what causes spalling concrete and how you can fix it, read on.

What Causes a Spalling Foundation?

The root cause of a spalling concrete foundation is water, and water intrusion can damage a foundation in a number of ways. Concrete is porous, so any water that drains towards the foundation will leak into it. If it freezes inside the foundation, it will expand and place pressure on the surrounding concrete. Concrete near the edges of the foundation will begin to flake and chip away due to the pressure.

Water intrusion can also cause the steel rebar inside of a concrete foundation to rust. Rebar expands as it rusts, and this places stress on the foundation in a similar way to freezing water. Stormwater runoff can pick up salt from the soil or from road deicer, and saltwater that enters your foundation will corrode the rebar even faster.

When water enters a concrete foundation, it will pick up some of the minerals present in the concrete. When it evaporates, some of those minerals will be brought to the surface — that's why spalling concrete often has limescale built up on it. Dissolving the minerals deep inside the concrete weakens it, which makes spalling more likely.

How Do You Repair a Spalling Foundation?

The first step is to call a concrete foundation service and have the spalling foundation patched. If any rebar has been exposed, it will need to have an anti-corrosion compound applied to it in order to prevent it from rusting further. Afterward, the concrete foundation service will mix new concrete and bond it to the spalling area using watered-down cement in order to restore your foundation. Repairing your foundation by restoring the damaged area will prevent it from spreading further.

Afterward, you'll need to remedy the drainage problems that caused your concrete foundation to spall. Make sure your gutters are unclogged and that your downspout is draining water away from your foundation. If you don't have gutters on your home, you may need to install them in order to divert water away. If your home is on a slope and rainwater naturally flows towards it, you may need to install French drains around your foundation — these are trenches buried underground that collect rainwater flowing towards your home and carry it safely away from your foundation.

Overall, repairing a spalling concrete foundation is a quick and inexpensive process as long as the spalling isn't too severe. Have it repaired by a concrete foundation service as soon as you notice that it's spalling. If you ignore the problem, the amount of concrete that's crumbling away will slowly grow until the foundation can no longer adequately support your home. By repairing the spalling area and improving your property's drainage, you'll be able to avoid more serious foundation problems later on.