Hardwood Flooring installation

Solid, sawn, hardwood planks have been an integral part of residential architecture for over 400 years. Since 1998, over 40 million square feet has been successfully installed over Warmboard. The long documented history of hardwood combined with our decades of experience tells us that traditional 3/4″ solid plank flooring is the gold standard and accordingly, that is our strong recommendation.

All wood products expand and contract with changes in humidity. Solid plank wood is naturally monolithic and expands and contracts most evenly. When these dimensional changes do occur, cupping, crowning and gapping at the edges may result. These changes are inherent to all wood flooring, regardless of the heating method. To minimize such dimensional changes, especially as humidity varies throughout the seasons, we also recommend quartersawn and/or rift cut planks due to their stability.

To further limit dimensional movement, ensure the hardwood has the proper moisture content at the time of installation. A good hardwood installer will know the ideal range for your geographic region (moisture content should be at the low end of this range). A moisture meter is required to determine when that moisture percentage is achieved.

A Word about Flooring Thickness

Many mistakenly believe that a radiant floor cannot have 3/4″ thick floor coverings. This thinking is based on a theory that the resulting higher R-value prevents the system from adequately heating the space. This may be true for low conductivity radiant panels, but not Warmboard. Apart from the fact that thicker hardwood, all things being equal, is better quality, its increased R-value causes more even heat across
your floor with the result that your feet will not be able to tell where tubing is and isn’t. With thinner material, the temperature variation across the tubing is increased causing what is known in the radiant industry as “striping” which makes your floor less comfortable. And comfort is the primary reason for Warmboard’s existence, which is why we recommend using 3/4″ hardwood over our panels.

Before the hardwood is on site, ensure the interior plastering is complete (and dry), and that the radiant system has been operating for a couple weeks in order to reduce any excess moisture from the Warmboard panels. In some locales, you may need to operate the air conditioner simultaneously with Warmboard to lower the indoor humidity. The hardwood should experience consistent, low humidity once on site.

Consider any moisture or humidity intrusion that may take place in the future, such as a crawl space beneath the Warmboard panels which could be dry in the summer and experience water intrusion in the winter. This could cause large humidity swings and excess movement of the hardwood flooring.

Circulate warm water under the newly installed floor for a few days before gradually bringing the water temperature up to the designed set point. For example, start with 100ºF, then increase to 120ºF. Finalize the set point according to the needs of the structure.

Ideally, the heating system should use “Indoor Reset” or another type of reset control strategy. “Reset” is a system for automatically resetting boiler temperatures (up or down), to better meet changing heat loads. This is an excellent strategy for hardwood floors.