I’m in the process of planning a radiant floor heating system for my home
(Long Island, NY). I’m adding to and renovating the entire house so access is not a problem. I’ve received design/quotes from three companies which vary greatly in price, complexity and method. The slab portion of the job seems straight-forward, but I’m confused about the staple-up portion. I don’t want to use aluminum plates, so I thought I would staple the PEX directly to the subfloor with foil faced ISO board 1-1/2″ below and FG insulation below that. Some companies reccommend 1/2″ PEX, some 3/8″ and provide different reasons. Some say the tubing should touch the subfloor and some say it should never touch the subfloor due to expansion.
Also there is some debate on wether it is better to zone with valves or pumps.