Cork flooring naturally has a high insulation value. By choosing a product that is 1/4″ to 1/2″ thick, the R-value will remain low (1.5 or less) causing heat output and response times to improve.
It will also simplify your mechanical design, allowing your cork floor to operate at the same water temperatures as tile, hardwood or carpet.
Established brands include Expanko Cork (expanko.com), American Cork (amcork.com), and Natural Cork (naturalcork.com).
The installation of an underlayment is required over the Warmboard surface before standard cork flooring is installed. We encourage a 3/4″ thick finish floor assembly, but priority should be given to matching floor heights throughout the house. Take care when fastening the underlayment to Warmboard because the tubing is obscured during this step. We recommend installing a 1/4″ APA listed plywood underlayment with a sanded face. For complete installation details, refer to the “Engineered Wood Construction Guide” at apawood.org. Complete the installation of the cork by following all the manufacturer guidelines and specifications.
Once the underlayment is installed, the cork is adhered using a urethane adhesive made for cork applications. Consider Dri Tac 7500 (dritac.com).
Cork laminate products contain an MDF layer sandwiched between two layers of cork. It is not necessary to put any barrier between the cork flooring and the Warmboard prior to installation.This flooring installs the same as a floating floor and requires no adhesive or nailing for proper installation, providing flexibility for the homeowner if they ever decide to change the floor covering.