In some cases, it may be better to either repair or replace the existing concrete rather than cover it. Serious structural issues in the original slab will eventually affect the new concrete layer as well, and you’ll need to replace the new concrete along with the old. You can save yourself time and money by repairing or replacing your concrete in the following cases:
The extra height would present an obstacle: The additional height from a new layer would block a door from opening or present a tripping hazard.
There are tree roots underneath: Growing roots can cause the concrete to lift and move, disrupting its stability.
There are significant cracks or pits: While these issues can sabotage a new overlay, you can fix them by repairing and resurfacing the existing concrete.
The concrete is deteriorating: Concrete that breaks apart under cleaning is beyond repair and needs to be replaced.
The surface is uneven: Although you can level concrete by adding a new layer, it may be more cost-effective to grind it down instead.
The slab is sinking: Sinking concrete is usually the result of an improperly installed subbase. In these cases, you’ll need to replace the concrete to fix the underlying issue.