Running pex tubing under wood floors between the floor joists and connecting to hot water heating system will keep floors warm in cold weather. Aluminum plates designed to snap over the tubing and screw to the floor above increase the heating effect. Packaged well, these aluminum heat transfer plates arrived undamaged. They don’t have prepunched mounting holes. The plates are very thin. Thinner than trim coil. Punching holes with a simple hand tool is easy. The plates fit fine overType B pex tubing.