Radiant Heat & Wood Flooring: Part 1

Wood floors are successfully installed over radiant heat every day. When deciding to install a hardwood floor over a radiant heating system, you will need to consider the experience of your installer, his understanding of the radiant heat system and his knowledge of the hardwood flooring being used, and most importantly – moisture. These variables need to be controlled or your dream floor will be a disaster.

Moisture is hardwood flooring’s most-feared and intimidating nemesis. Even without radiant heat, moisture is the leading cause of wood flooring problems. Add radiant heat, and the potential for moisture problems is exponentially increased because the radiant heat dramatically exacerbates the moisture fluctuations in a wood floor.

To understand better, some basic information about radiant heat may be helpful. Radiant heating consists of "radiant energy" being emitted from a heat source; this radiant energy (commonly known as
heat) then penetrates all objects in its path, including people. For example, the heat felt from the sun or fireplace is radiant heat. Radiant energy travels through a space without heating the space itself (unlike forced-air heating systems which actually warm the air). When radiant heat comes across a cooler surface (like a human being), it attempts to equalize the temperature difference, thus giving off heat. Most radiant heat systems used in the United States today are hydronic, meaning the subfloor has plastic tubes through which hot water flows. The water may be heated by anything from natural gas or electricity, to solar energy. A radiant heat system heats all the materials around it. In the process, it drys everything out, while driving moisture from the joists, slab, subfloor and flooring.

There are many product choices you can make to increase the chances of a successful radiant heat flooring installation. However, there are no guarantees.

• Quartersawn & Rift-sawn Floors: More dimensionally stable than plain sawn wood flooring. They expand in height, whereas, plain sawn boards expand in width.

• Narrower Boards: Shrink and swell less than wider boards. Less than 3” wide is recommended.

• Engineered Floors: More dimensionally stable than solid wood flooring. The more plies, the more stable the product.

• Reclaimed Woods: Have a tighter pattern of growth rings, making them more stable.

• Parquet: Less expansion and contraction tendencies.

• Dark floors: Darker colors make seasonal gaps in boards less noticeable.

• Floors with Obvious Grain Patterns: They also downplay the appearance of seasonal gaps between boards.

• Distressed Flooring: Minimize the appearance of seasonal gaps.

• Beveled Edges: Make seasonal gaps less obvious.

• Tongue and Groove Strips

• Dimensionally Stable Species: North American Oak, American Cherry, and American Walnut are known for their inherent dimensional stability. Species that are more dense, such as Beech, Australian Cypress, Maple, Brazilian Cherry, and some Bamboo products are less stable. Exotic species can be particularly susceptible to problems resulting from bad drying practices.

• Products made Specifically for Radiant Heat

In Part 2 of our series on Radiant Heat, we will talk about the best ways to stabilize your floor and avoid disaster.

For more helpful information on hardwood flooring options, or to buy the right flooring for your radiant system, please visit www.GateWoodFloors.com.