let's talk concrete

concrete spalling

The most common issue with concrete which we are called to inspect and fix is concrete spalling. When concrete is used in construction, steel bars or steel mesh can be used inside the concrete slab as reinforcement. When exposed to air or water, these steel reinforcements can corrode, which causes the reinforcements and thus the concrete to expand. Concrete spalling is a common building condition, and is especially prevalent in buildings which are close to saline environments, such as ones along the coastline. With premises located along the south coast, we are very experienced with this type of building defect, especially in balcony slabs that are exposed.

Concrete spalling is often also called “concrete cancer” due to the progression of the corrosion. Once the concrete has cracked, it further exposes the steel to water and air, speeding up the process.

detecting it

Our builders are particularly experienced at dealing with concrete cancer and it can sometimes be detected by the presence of rust stains, cracks in the concrete or small pieces of spalled concrete on or near the surface which have broken off the main slab. These signs represent a deeper issue however, and will generally require an invasive investigation to see how far the reinforcement has been compromised in the concrete slab.

break it out

When concrete spalling has been determined to affect your building, our tradesmen are ready to break out the spalled concrete and will repair it so that it looks brand new! It is always recommended that these repairs begin sooner rather than later as the concrete spalling process only speeds up with time and the ramifications of waiting can be costly, not only in terms of the money you will have to spend to repair it, but in terms of the compromising of the structural integrity of the building.

See the image below for an example of concrete spalling inside a balcony slab in East Sydney. This is an exposed piece, and you can clearly identify the rusted steel reinforcement bars that are simply not able to be seen without an invasive procedure. This entire slab required replacement as the structural integrity of the balcony was severely compromised.

CONCRETE SPALLING EXPOSED IN A CONCRETE SLAB