Subfloor For Engineered Hardwood Over Concrete

Although you can attach hardwood directly to concrete with glue or nails it s not advisable.

Subfloor for engineered hardwood over concrete.

The subfloor is the foundation beneath finish flooring materials. A moisture control membrane is recommended any time a wood subfloor is installed over concrete. The combination of the underlayment and flooring raises the height of the floor 1 1 2 in so be sure the extra height doesn t create problems around cabinets in doorways or at transitions to other types of flooring. Nail down subfloor system get 3 4 inch minimum cd exposure 1 plywood subfloor panels 4 foot by 8 foot sheets.

If you have a subfloor that consists of wood on top of concrete you ll need to test both floors. If the wood can t expand sideways it will twist warp or cup as it absorbs moisture. How to install engineered wood over concrete engineered wood flooring offers the timeless look of hardwood but is perfect for basements and other areas where moisture can be an issue. If necessary add vapor retarder before applying underlayment especially recommended if 3 4 inch wood flooring is installed over concrete.

Consult the product data sheet for instructions regarding specific trowel requirements. You ll first have to install 3 4 in. Wood floor over concrete than over a wood subfloor. In general use a notched trowel to spread the adhesive.

After installing a vapor retarder if necessary cut your plywood panels into 2 x8 or 4 x4 sections. If the slab is out of specification consider grinding floating or both. Installing engineered hardwood flooring over concrete too tight against a stationary object will not allow room for normal expansion and may cause a failure. As with a floated subfloor nwfa recommends a vapor retarder for glue down subfloors when installing wood flooring over concrete.

In this case the subfloor is the concrete slab. But it s considerably more difficult to install a 3 4 in. Typically manufacturers will specify a flatness tolerance of 1 8 in a 6 foot radius and or 3 16 in a 10 foot radius. Make sure the concrete slab is flat to the wood flooring manufacturer s specification.

Check for cracks and crumbling. Subfloor must be flat. In on grade and below grade installations moisture control systems are always recommended and required when calcium chloride readings are greater than three pounds or when relative humidity readings are greater than 75 percent. On wood frame floors the subflooring provides a continuous structural surface over the floor joists.

The concrete subfloor must be sufficiently strong to safely support the flooring furniture and people in the room. Wood needs to move as the humidity increases and decreases throughout the year.