You may be considering re-doing your garage or pathway to your home. And the thought may occur to you, "Can I put new Concrete over old Concrete." In short, it is possible to apply new Concrete over old Concrete. However, before you start undertaking this very large project, there are a few things you will want to consider.
While it is possible to apply Concrete over Concrete, certain circumstances may prevent you entirely from doing so. Some of those circumstances are;
Something such as a door or staircase obstructing you from doing so.
Environmental factors such as tree roots have caused the existing Concrete to lift or move.
If there are cracks in the Concrete or it is not level. If this is the case, you could always break out some of the concrete, so it is relatively level prior to applying the new concrete. This is a great idea to do anyways so the new concrete has something to grab onto.
If the previously mentioned issues don't apply to you, you're good to go to attach new Concrete over the old. You will also want to follow these steps;
Step One) You will want to make sure you have all of the proper tools for this project;
Concrete screed
Concrete rake
Bull float
Mag float
Shovel
Chute
Boots
Gloves
Safety glasses
Bush Hammer Bit
Breaker
E-etch
Neutra clean
Step Two) Concrete likes a rough surface, so in order to ensure your new concrete adheres to your old concrete you will want to roughen up the surface a bit. This can be achieved by using a breaker bit to chisel it out, or a grinder. The thicker you apply the concrete, the more aggressive you want the repair site to be. After its all roughened up, wash the old Concrete surface to remove any loose debris or Concrete. It’s a good idea to give your surface a good scrub and etch with a citrus cleaner such as E-etch, and don’t forget to rinse it off with Neutra clean.
Step Three) Once the surface is dry, you will want to brush or roll on a bonding agent lightly onto the Concrete so you can bond both new and old Concrete surfaces. This needs to be done right before you are ready to poor, as the bond is recommended to be wet or tacky when the new concrete goes down. If the Bonding agent dries, it acts like a bond breaker and then you will have some issues.
Step Four) Pour your new mixture of Concrete and start the Concrete application as normal. You will want to make sure that the surface is appropriately levelled and graded. If the surface isn't levelled, this can lead to problems such as the Concrete starting to crack.
Product Links:
https://unicon.ca/redi-mix-concrete-55lb/