Plywood Over Concrete For Underlayment

On projects where deflection of the plywood is a concern some manufacturers recommend applying the underlayment over two layers of 3 4 inch plywood for better rigidity.

Plywood over concrete for underlayment.

Nevertheless this is not all that uncommon. Plywood is available in 4 x8 and 4 x4 sheets. Unlike other underlayment products you can use it with confidence over concrete surfaces without needing to first perform a calcium chloride test of the slab. If necessary add vapor retarder before applying underlayment especially recommended if 3 4 inch wood flooring is installed over concrete.

Wood panels such as plywood or oriented strand board are common subfloor choices. Some installers will lay vinyl over existing osb or plywood subflooring if it is in excellent condition. The preferred underlayment for vinyl flooring is 1 4 plywood. Installation over concrete with a calcium carbide reading of greater than 2 5 percent.

Pouring concrete over plywood can be even more challenging than installing plywood over concrete. Repeat the process for all of the other pieces of plywood that need to adhere to the concrete. It can also be used under hardwood laminate and carpet but this is much less common these days because subflooring is typically smooth enough for these materials many of which are installed with a different type of underlayment or pad. It s best to place the underlayment over 3 4 inch thick plywood fastened with screws at 12 to 16 inch intervals to help decrease deflection and add stability.

The reverse concrete over plywood. Alternatively screw rows of treated 1x4s to the concrete 16 in. Nail down subfloor system get 3 4 inch minimum cd exposure 1 plywood subfloor panels 4 foot by 8 foot sheets. It might be done to create a subfloor for ceramic tile to be installed over an existing wood subfloor or for making a concrete countertop.

Tap down on the plywood with a cement block to ensure all air bubbles are expelled. Once you ve installed a vapor retarder install your subfloor. Reviewers frequently state how simple it was to install this floor underlayment and how incredibly cushioned the floor feels. To install a floated subfloor system first place a layer of plywood subfloor panels with the edges parallel to the wall.

Lay 6 mil polyethylene sheeting over the concrete to minimize moisture migration from the concrete up into the wood flooring. Run your hands over the surface of the plywood and push down firmly to secure it in place.