Nail Down Hardwood and Cork underlay

Hardwood flooring is the most common form of flooring in North America. It is a tried and tested floor finish that looks great and wears extremely well. Cork underlay can be used underneath hardwood floors to remove some of the echo in the space or to add additional thermal insulation.

Installing hardwood is normally a permanent flooring solution using glue, nail (sometimes referred to as “cleats”) or staples. Some engineered hardwood floors can be installed using the floating floor method which means the floor is not anchored to the subfloor.


Cork underlay has special characteristics that require certain techniques to be used when it is installed underneath hardwood. The main consideration is that cork underlay should never be pierced. This rules out the favourite form of installation of nails or staples. Leaving only glue down or floating floor as the installation option.


Glue down hardwood is an art form which produces an excellent floor – it also adds to the overall cost and duration of installation. It is time consuming with a few pitfalls that, if not dealt with correctly, can cause floor failures. It takes finesse and in-depth knowledge of adhesives and their application.


For this reason most installers prefer to use nails or staples to fix a hardwood in place. It is easier, faster and results in stable floor in a short period of time. Cork underlay changes the installation approach to hardwood. Instead of the fast and easy nail or staple gun, the flooring professional must now look towards the glue down installation for solid hardwood as well as many engineered products.


Cork underlay is normally glued directly to the plywood subfloor using trowel on wood adhesive. The adhesive is allowed to cure before the installer moves on to the flooring installation. The hardwood is then glued in place (often with the same technique and same adhesive used for underlay) over top the cork. Once the floor is in place the adhesive is allowed to cure before the floor can be used.


Floating an engineered hardwood (usually involves gluing the tongue and groove together without attaching the floor to the subfloor) over cork flooring is a rather simple process. The cork sheets are laid out over the subfloor and the floating hardwood is then laid over top. There is no need to glue the underlay in place. Both the floor and the underlay are considered a floating installation.