Laying plywood on a concrete floor under a laminate

Many homes today are built on concrete slabs rather than full-sized basements. While the basement is nice to have, these are additional costs that many new homeowners simply cannot afford. But when they want to renovate their house later, this concrete slab can be a problem.
What to put under the laminate on the concrete floor? Before laying the laminate over concrete, it is necessary to install a plywood floor.

How to lay plywood under a laminate on a concrete floor

What to lay under a laminate on a concrete floor? If you install plywood on an existing dry concrete floor, you should not have any problems. However, the new concrete floor contains a lot of moisture.

Thus, you need to let it harden for at least 60 days before even bothering to check the humidity level. The moisture level of the concrete must be reduced to 5.5% before installing the plywood base. Floors below the level (i.e. basement floors) may never reach this point.

If you live in an area that could be flooded, or there are flooding cases in your particular home, you can reconsider laying parquet. Water damages wood and trim on a wooden floor. Parquet floor in the basement in this case should not be installed.

What to lay a laminate on a concrete floor? Commonly used plywood is three quarters of an inch thick. Some people recommend using pressure-treated plywood, but this is not necessary. Even the use of pressure-treated plywood in a basement prone to flooding will not help, since the parquet floor installed on it will not be subjected to pressure treatment. If there are bumps in the concrete, they must be repaired before installing the plywood floor.

Parts of concrete will prevent plywood from sitting level. Similarly, if the concrete has a joint from two separate fillings that is not smooth and even, this will lead to an uneven arrangement of the plywood base, which will ultimately cause problems with the installation of the laminate. Small gaps, such as joints between individual plates, are not significant if they are at an even height.

A moisture barrier must be installed in front of the plywood. Usually this is a plastic film. The type of asphalt felt used for roofing is another alternative that can also be used. Plywood itself must be laid with a long direction perpendicular to the direction of the grain on the floor. This will help prevent cracking when the floor seam is directly above the seam in the plywood.

There are three ways to fix plywood to a concrete floor. It:

  1. Screws - concrete screws, provide a very reliable fastening. They require the use of an impact drill to create tapping holes, and a worker to fix the screws. When installing, the screw heads must be at the same level or lower compared to the surface of the plywood. Screws should be installed every 40 centimeters.
  2. Powder fasteners - concrete nails embedded in the floor work well if they can be installed when the heads are at the same level or slightly below the level. They cannot be dropped or moved deeper after they have been inserted with the powder driven tool, so run the test before using them. Like screws, they should be 16 inches apart.
  3. Adhesive Mastic - New adhesives provide a great alternative to traditional installation methods. When using adhesive mastic, vapor barrier is not used, which provides some savings. However, these adhesives are expensive, resulting in a higher overall cost. The mastic itself is rubbed in place, creating a certain barrier against moisture. After installing the plywood base, check the edges for protrusions caused by the plywood sheets not lying flat or of different thicknesses. Any irregularities found require filling with a wooden floor putty followed by sanding to provide a smooth, continuous surface for mounting the wooden floor.

Possible errors and their elimination

If there are too many bumps on your base, you need to level the floor before starting the installation. Fill holes or low areas with cement and latex. Let it dry completely before your flooring is installed.

Your base should also be tilted. If the slope is large, it must be corrected.

Dirt and debris can damage your floors over time. Always clean and dry them before starting any type of laminate installation. And the foundation plays a crucial role in the long-term use of the laminate.

Watch the video: How to Install Laminate Flooring on Concrete in the Kitchen Mryoucandoityourself (March 2024).

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