What Causes Concrete Spalling?

Concrete spalling – what is it

We see concrete every day. It is the material used for our driveways, sidewalks, and even the foundations of our homes. While we understand the material, what does it mean to have concrete spalling?

Flakes of material that are broken off a larger solid body.

The concrete is flaking off the larger body. Your concrete will look flaky and crumbly as the larger body slowly deteriorates.

The cause

The presence of moisture will always be the number one culprit. You see more severe concrete spalling as the water begins to pool and has nowhere to go.

There are two types of concrete spalling:

1. Concrete spalling on flatwork.
   • Damage to any concrete work along a horizontal plane of your property.
2. Rebar causing spalling from rusting.
   • The iron or steel is oxidising, causing the rebar to rust as it contacts moisture. Iron combines with oxygen in the presence of water.
     • Also known as Oxide jacking.
   • The rust is causing expansion. The concrete is breaking since it has nowhere to go.
   • Improper concrete curing / lacklustre finishing techniques.
   • Lower-quality concrete.
   • The wear and tear of the freeze-thaw cycle.
   • Electrochemical reactions.

Spalling can be triggered by various factors:

• Improper concrete curing / lacklustre finishing techniques.
• Lower-quality concrete.
• The wear and tear of the freeze-thaw cycle.
• Electrochemical reactions.

The potential dangers of spalling

Rebar and concrete being exposed to high amounts of moisture from constant leaks can result in a building’s concrete chipping off in certain areas, compromising the integrity and weight distribution of the entire structure.

Suppose the issues are not taken care of immediately. In that case, the spalling will continue to deteriorate the concrete to the point that the building structure will not be able to handle it anymore.

A disastrous situation could be prevented if the issues aren’t neglected.

If you’re in charge of the building owner, people’s lives can also be on the line. If there is an issue you’ve been made aware of, take care of it.

Any structure with an issue to the point of compromising a building’s integrity must be addressed immediately. This also includes homes and any other living spaces.

Thankfully, this is a worst-case scenario. The spalling you endure as a homeowner can be different. If the surface of your driveway is experiencing spalling, it isn’t catastrophic. The flaking doesn’t look the most appealing, but that’s a better outcome than a building collapsing.

If the damage to your concrete on a walkway or driveway is bad enough, that could create a tripping hazard. Other than that, spalling is primarily a visual issue.

Sometimes, moisture makes it to the footings of homes, causing foundation damage to the structure. If this is happening, find someone to fix the footing ASAP. A severely damaged footing can compromise the structure and foundation and decrease the home’s value.

How spalling is fixed

Grace Foundation Solutions can repair damaged concrete if it is not caused by rebar. However, the concrete must be replaced if the damage is beyond repair.

We focus on addressing issues directly rather than hiding or exacerbating them. Our approach involves identifying problem areas and enhancing overall appeal.

If concrete spalling is caused by rebar, the metal must be removed to prevent future rust. The rusted sections should be replaced with new rebar or polyurethane to ensure the concrete’s structural integrity.

If the damage is severe, you may need help to achieve your desired selling price for your home.

If your home experiences more damage, its value will likely decrease. It is important to note that if you decide to sell your home, you must legally disclose any existing damages.

Selling your home may become more challenging when targeting the average homebuyer. Many are hesitant to deal with potential issues that may arise during the process. Cash buyers can negotiate and potentially use any problems they find as leverage to reduce the purchase price. This could result in the final sale price being up to 20% lower than expected. 

So, if your home was originally worth one million dollars, they will now see its purchase price as $800k.

That’s a pretty penny you’re losing; the repair cost would be a fraction of this figure, so the question should be, why would you not carry out the repairs?

How to prevent concrete spalling

Prevent moisture from accumulating and pooling around your foundation. Proper water mitigation ensures moisture is directed away from the foundation. This will help prevent it from seeping into the rebar and footings, ultimately preserving the integrity of your structure.

If you see concrete spalling, address it immediately. Over time, it will only get worse and more expensive to fix.

If you’re reading this at home, you don’t want your structure compromised, and we don’t want you to lose value in your most significant investment.

Grace Foundation Solutions can repair your spalling!

We specialise in providing relief when your home is in need. Our focus is on preventative maintenance to ensure your peace of mind. Take care of any spalling issues promptly to avoid any worries in the future.

If you’re worried about the condition of your foundation and concrete, Grace Foundation Solutions can help.

Call us at 0800 436 349 or click the link below to schedule a free evaluation today.

Feel free to contact us if you’re experiencing any issues with your concrete.

https://foundations.co.nz/contact/

Written by

Richard Ushaw

Richard is the Director of Grace Foundation Solutions. He has been in the foundation repair industry since 2018 and manages a company founded in 2010. During his career, he has helped over 6,500 homes and structures throughout New Zealand.