When the bathroom is underfloor heating, should it be laid with extruded plastic boards?

This still needs to be paved, the bathroom is originally small, if the water separator is better here, if it is not in that heat is less is the need to lay the insulation board, how much is the floor heating installation, mainly depends on the equipment you choose, the floor heating installation mainly consists of boilers, pipes, water separators, thermostats, auxiliary materials, labor, etc., among which boilers, water separators, pipes and labor are a relatively high proportion of the part, labor is not to say, each place is different, labor costs are not the same, the choice of boiler mainly depends on what brand you choose, How much power, etc., different prices are not the same, the pipeline is also mainly based on the brand, the water separator depends on the brand you choose and the material, etc., so how much money is not easy to say, it is recommended that you find a few more local markets to ask, so that you can, Shure floor heating free door-to-door measurement, out of the plan, quotation.