Because Duraamen specializes in polished concrete flooring systems that can go over many different surfaces, we have repeatedly been asked about whether or not you can install concrete over plywood. The answer is yes! You can install concrete over plywood.
There are a few considerations, but also some good reasons why you would want to do this. Let’s look at those. The wood surface must be firm in order for the concrete surface to be a good match. In other words, the plywood surface must not have any deflection or bending in it. If it does, it needs to be strengthened first.
The wood must be prepared in certain ways, with no seams and screw heads showing. Your lathe, which will go on top of the prepared wood, must be adhered firmly and cleanly. The overlay may be as thin as 3/8 of an inch, so the surface prep is keenly important. If you're applying the concrete topping to a wood floor where you have moisture concerns, a flexible waterproofing membrane over the plywood is all that is needed to provide protection from moisture.
Why would you want to do this? When you are remodeling, there are usually two options. One is to tear out what is already there and start over. The other is to use what is there and modify it so it works. In many homes, plywood was chosen as a flooring substrate and applying concrete over plywood gives you more options for using what you already have.
Rather than tear out a wooden floor and installing concrete, your wooden floor can be turned into a beautiful concrete floor with a concrete microtopping. When installed correctly, your concrete over plywood floor will not permit moisture through, will not warp or buckle, and will come with all the benefits of concrete in an easy-to-care-for floor.
Duraamen’s Param 5500 goes on thin, in a 3/8" to 1/2" thick application. It lays down ultra flat. Param 5500 can be applied over other surfaces besides wood, but if you use it on wood, it can be a final surface. It can also be modified with the application of a product such as Skraffino to give it a look of hand applied aged concrete appearance.