You can lay new concrete on top of old concrete. However, unsolved problems with old concrete, such as cracks or frost, will be transferred to new concrete if not fixed. In addition, you need to pour it at least 2 inches thick. The simple answer is YES, you can pour new concrete over existing concrete.
In short, yes, you can put new concrete on top of old concrete. However, there are some things to consider and prepare for the work that needs to be done before moving forward. Like everything else in the world, concrete also has a lifespan and wears out over time. Imperfections form when concrete hardens or sinks into the ground.
Pouring fresh concrete over existing concrete is a common way to level old slabs and repair damage. You can add new concrete to an existing concrete slab if the old concrete is in good condition. You will need to thoroughly clean the old concrete surface and use a suitable concrete bonding agent before pouring the new concrete to meet all structural requirements. Skeptics do not recognize that pouring on the surface of solid concrete is no different from pouring on a super-compact stone base.
Whether it's indoor floors or an outdoor concrete deck, concrete surfaces suffer wear and tear and often need repairs and maintenance. You can pour new concrete over small cracks or worn surfaces, but if it's more than that it will be worth investigating why the damage occurred and fixing the problem before adding a new layer. In the latter case, you need to tear off the concrete and solve the problem of the root of the tree before pouring a completely new slab. If the concrete does not move, move or settle, then it's okay to pour new concrete on it.
You can leave the paint on the concrete, place some plastic and pour the new concrete over the paint and plastic. Ensuring that your slabs are tightly packed can also help ensure that excess water doesn't go underneath the concrete. The two pieces of concrete will not make a perfect bond; however, following the instructions correctly and using a suitable adhesive agent will make the concrete strong and sufficiently bonded. It is essential to properly prepare and clean the existing slab before placing the new concrete on top.
The slab poured onto an existing concrete slab is more prone to frost and crack damage due to the joint between the two layers of concrete. Pouring a new layer of concrete over an existing walkway, patio or porch will raise the level by several centimeters. If you pour something thinner than 1.5 inches, you won't have enough cement paste on and around the aggregate to get strong concrete. If the concrete has been damaged by weather or heavy use, you can re-coat the concrete to repair and restore minor damage.
A bonding adhesive is used on concrete to ensure that new concrete adheres properly to existing concrete. Joining the new slab to the old slab involves creating a joint that structurally connects the two while providing a flexible point for the two pieces of concrete to respond to weather and other external manipulations.