Spalling refers to minor cracks or bulges of concrete on the ceiling caused by the corrosion of the steel bars embedded in the concrete slab.
Over time the ceiling will dislodge as the steel corrodes, exposing the steel bars that are meant to be embedded inside the concrete.
HOW TO FIX IT
You need a contractor to fix this and these are the steps they will carry out:
You can paint the ceiling every three to five years to slow down the rusting and check the ceiling for cracks that can accelerate the rusting. Keep the humidity in wet areas like bathrooms or toilets to a low through open windows and vents.
- Remove the concrete around the area of the spalled ceiling.
- Clean the rust on the steel bars.
- Apply the bonding agent to affected surface.
- Patch up the area using polymer modifier cement mortar or epoxy mortar.
- Paint the area back with matching color with the rest of the area.