Pouring new concrete over existing slabs is a great way to give your home or business a fresh look. But it's important to do it the right way to ensure that the new layer is strong and durable. Here's a step-by-step guide to pouring new concrete over old. First, use wooden braces or reinforcing mesh to place the new concrete over the existing slab. This will help form a bond between the two layers.
Then, spread a concrete bonding agent over the existing slab to further strengthen the bond. Next, pour the new concrete to the desired thickness and level the surface with a trowel. If you're pouring on an existing slab exposed to vehicle traffic, such as a driveway or parking lot, you'll need to pour at least two inches thick and use smaller aggregates. You may also want to incorporate reinforcements such as welded wire mesh or mixed fiber into the concrete. If you're pouring something thinner than 1.5 inches, you won't have enough cement paste on and around the aggregate to get strong concrete.
When considering the thickness you want your new concrete to have, it's important to consider the environment where it will be. Once you've poured your new concrete, finish the work by priming the surface and pouring a curing compound over it. This will give your concrete base a fresh layer and help prevent early wear. The curing compound usually takes seven days to cure. It's also important to note that if you have unsolved problems with your old concrete, such as cracks or frost heave, they will be transferred to your new layer if not fixed. If you can't find a conclusive answer to these questions, it's probably best to remove the old concrete and find out why it settled or crumbled before pouring new concrete. Finally, remember that although it is possible to bond new concrete to old concrete, it's important to do it correctly in order to prevent any cracks or gaps from forming too quickly.
Pouring new concrete over existing slabs is simple and effective when done correctly.