Hydronic Floor Heating

Hydronic floor heating has been put into the slab. There are three return pipes to a manifold which runs off a boiler. The boiler, a linear is a fireplace and although heating the living room and looking nice as a fireplace is primarily heating water for the floor heating. orginally we wanted to have a wetback on a combustion stove, however further investigation lead us to believe that a combustion stove only gets about 15kw of power and floor heating requires around 20. You can still run  it through a combustion stove, but its shelf life would shorten dramatically. A separate boiler was the answer and a fire in winter (although probably not really needed) was the answer. Our flooring cover is the next issue we will have solve as we are avoiding any glues etc that will be emitted as VOC's once the floor heating is activated. We are thinking floor boards which will stop alot of the heat from the floor heating, however the main purpose of the heating is to take the chill of the insulated slab, which it will do quite well, next to find some well seasoned timber.