Guidelines for Hardwood Floor Installation over Concrete 

11/20/2023

Hardwood floors have retained their popularity over the years, and are still considered to be an excellent addition to any home. Natural wood’s soft hues, when combined with the natural and organic grains, create a feeling of warmth and style instantly. There is a common perception that hardwood floor installation over concrete is not possible. This perception is far from the reality and it is certainly possible to install hardwood over concrete. However, you need to consider numerous factors and make sure that the installation is done only by a professional.  

Discussed below are the most important factors you should consider before deciding to install hardwood over concrete.  

At or Above Ground Level:  

It is possible to install solid hardwood floors at or above ground level in presence of dry concrete and appropriate subfloors and vapour retarders. Below ground level, however, moisture can pose serious concerns for solid hardwood. Therefore, it is better to use engineered wood floors instead of solid hardwood.  

Please remember that wooden floors should never be subjected to conditions that are extremely wet. Before delivering the materials to the site, please make sure that all the outside windows and doors are in place. Also, all concrete, sheet-rock, and masonry used for installation should be completely dry. The building should be properly ventilated in warm weather. In winter, near occupancy level heating should be maintained at least five days before delivery of the flooring.  

The Subfloor:   

One of the best ways for installing hardwood flooring over concrete is to use a ¾ inch thick wood under layer. This underlayment will make it much easier to install hardwood over concrete.  However, please be mindful of the fact that this will elevate your floor surface by approximately an inch.   

Dryness of the Slab:  

Whether new or existing, concrete slabs must be dry before the installation of the subfloor. To ensure best results, test several areas of each room for excess moisture. Abstain from installing hardwood floors, if the moisture content of the slab is too high. If the slab is new, allow it to dry naturally before the installation. This drying process can be accelerated by with heat and ventilation. In general, concrete slabs that are less than 60 days old are considered to be too wet and hence unsuitable for hardwood floor installation.  

Vapour Retarder:  

Before installing hardwood over concrete, install a proper vapour retarder on top of the slab. This will restrict the normal slab moisture from reaching the finished floor. Some popular choices for this purpose include 6 mil polyethylene sheathing or asphalt felt layers with asphalt mastic.   

Acclimation: 

Try to ensure that the flooring materials are delivered when the site is prepared and stored in the rooms where you plan to install them. For flooring less than 3” in width, acclimation refers to a moisture difference of less than or equal to 4% between the wood and the subfloor material. On the other hand, this difference should be within 2% for hardwood flooring 3” or wider. You would require a moisture meter to find out whether the flooring has been acclimated properly.  

If you have any other questions about installation hardwood flooring at your home, please contact the expert technicians at Enoak.