We have a radiant heat system installed 2 years ago as part of a remodel of our daylight rambler. The downstairs is heated by radiators, the upstairs by the in floor system. The tubing for the radiant system is clipped to the subfloor of the upstairs in the same interstitial space as the domestic water lines. The only insulation in this space is between the domestic water lines and the basement ceiling drywall. The water temperature from our cold water taps measures up to 92 degrees for up to 10 minutes in the winter when the radiant system is on and up to about 80 degrees in the summer or when the radiant system is off. The domestic water lines are piped with Pex with Wersbo connectors, one of which popped off 2 weeks ago and flooded the basement at which point we had to tear into the ceiling and saw how close the pipes are located to each other.

What is the standard for insulation when radiant systems are run in the same joist space with domestic water lines and is our only option for correcting this problem tearing into all the drywall and insulating the domestic water lines (would fix summer issue) and insulating between the domestic water lines and radiant tubes (to fix winter issue)?

Thanks!

At this point in time if you want to insulate or make a barrier between the domestic cold water lines and your radiant heat lines you will have to tear out any materials covering them then insulate and replace the covering.

Most if not all companys that install heating pipes (PEX.Copper or others) do not use the same chase or space that is used for the domestic water lines but there is no specific law or rule that says they cannot be combined into one area at least in my area of work. Any interior runs of pipe domestic water require NO insulation and the install of the actual heating system insulation requirements are stated in the installers manual. Usually once again the heating line install is not required to be insulated but is required to be installed with the proper radiant attachments (pan reflectors etc) depending upon the area and type of install being done.

It sounds to me like not much thought was given to this situation during the install and with the line poping off it might not be a good install all the way around. If those joints are made correctly they do not pop off.