We want to install a wet underfloor heating system to our ground floor. We have suspended timber floors with a metre void beneath. We know to insulate between the joists (still decided the best insulation to use - any suggestions are welcome!) Ideally we would like to reuse the existing timber floor boards as the final floor finish - is this possible or will it be subject to expansion and shrinkage? Is it better to simply use an engineered timber floor instead?
 
Many thanks