I can provide some guidance on the topic.
Installing floor heating under a wood subfloor without removing the existing subfloor and insulation is possible, but it can be more challenging than installing it in other scenarios. The success of this installation largely depends on the type of floor heating system you choose and the existing conditions of your subfloor.
There are two main types of floor heating systems to consider:
Electric radiant floor heating: This system uses electric heating cables or mats installed directly beneath the floor. Electric systems are generally thinner and can be installed without adding significant height to the floor. They are suitable for retrofitting under existing floors.
Hydronic radiant floor heating: This system uses hot water tubes embedded in the floor to provide heat. Hydronic systems are more common in new constructions, as they are typically installed during the initial construction phase. Retrofitting a hydronic system under an existing wood subfloor can be more complicated and might require removing the subfloor.
In the case of electric radiant floor heating, you have a better chance of installing it without removing the existing subfloor and insulation. Here are some steps to consider:
Evaluate the subfloor condition: Ensure that the existing subfloor and insulation are in good condition. They should be dry, free of mold or damage, and able to support the additional weight of the heating system.
Choose the right heating system: Opt for a low-profile electric floor heating system that won't add too much height to the floor. Some electric systems come in thin mats or cables that can be installed on top of the subfloor.
Prepare the subfloor: Clean the subfloor thoroughly, making sure it's free of debris and level. If there are any irregularities, consider using a self-leveling compound to create a smooth surface for the heating system.
Install the floor heating system: Follow the manufacturer's instructions to install the electric heating mats or cables on top of the subfloor. Some systems can be adhered directly to the subfloor using an adhesive, while others may require a thin layer of thin-set mortar.
Flooring installation: Once the heating system is in place, you can install your wood flooring directly over it. Engineered wood flooring is often a better choice for floor heating systems, as it can handle temperature changes more effectively than solid hardwood.
It's essential to consult with a professional contractor or an expert in floor heating installations to assess your specific situation and ensure that you choose the right system for your needs. They can also provide guidance on how to avoid any potential issues during the installation process.