Have you ever touched a mug of hot chocolate and felt the warmth it gives off? Or, taken a walk outside and felt the heat from the sun beating on you? Well, if you have you have felt radiant heat. Radiant heat is becoming more popular as a form of heating your home. Instead of circulating heat by moving the air in the room, a radiant system heats objects – including people. It does not heat the air directly as do more conventional forms of heating, such as baseboard or forced air circulation. The most common form is radiant floor heating, which uses electric cables or small tubes of hot water embedded in a concrete floor or under a tiled floor. The system will heat the floor until it reaches the desired thermostat setting. Then it passes through the floor to warm all other objects in the room all the way up to the ceiling.

Having a warm wood floor is very desirable and radiant heat can be used with wood flooring. With radiant heat the floor may gain moisture or dry out faster than a similar floor in a home with a conventional heating system. When installing wood floors in any situation, moisture content is a key factor to successful floor performance. Adding heat to the floor makes attention to moisture even more critical. Most movement that occurs in wood flooring is due to moisture and that movement will happen in all wood floors. Therefore, the more constant the moisture content is maintained, the less likely there will be any problems with the floor. Gaps between the boards and checks (cracks in the board) are a result of the moisture content being too low. Warping or cupping is the result of the moisture content being too high or uneven. In either case, it is usually a result of not allowing the wood to adjust to its environment before it is installed.

When dealing with a radiant heating system run the heating system at least 72 hours before accepting delivery of the hardwood flooring. Then open the flooring up and condition the flooring for 72 hours before installing. Keep track of where the floor joists are for nailing purposes.

It is also important to note that not all wood flooring is recommended for radiant heat. Engineered flooring and laminates work the best with radiant heat because of their dimensional stability. Floating floors that are either engineered or solid are also highly recommended because they tend to move as a unit to help accommodate moisture content changes. Quarter sawn flooring is always more stable under conditions of extreme moisture or heat, and is always a good choice over radiant heat, especially when going with flooring wider than 4 inches. Plain sawn wood will move more than quarter sawn especially when it is over 4 inches wide. Strip flooring is also a better choice than plank flooring, because narrow boards expand and contract less than wide boards do. Using narrow boards also means there are more seams in a floor to take up movement. If a solid hardwood floor is desired, it is recommended not to use anything over 3 ¼" width.

The best thing to do when making the decision to put hardwood floors over radiant heat is to consult the manufacturer's guidelines in all cases for compatibility and instructions to ensure you choose the right wood floor.

Bellawood recommends Warmboard® radiant sub-floor system – this is an aluminum covered structural plywood. Visit them at www.warmboard.com.