Replies

1. 
   jlyda | Mar 02, 2020 08:48am | #1

   Totally fine, unless your water lines are so boiling hot that it will melt the foam (this would be a very rare occurrence). It should increase the efficiency of the water heater/boiler actually. I would be more concerned about electrical, but that is probably fine as well if it’s new work with proper modern wiring methods being used. If wrong conductors, wire etc is in place the wires can get quite hot. Also, if too many wires are bundled together it’s a fire hazard, but that’s true even without foam. If you are going over old knob and tube be cautious. There’s a good chance that will retain too much heat as the wiring is not great. An experienced electrician can speak more on that.

2. 
   suburbanguy | Mar 02, 2020 12:59pm | #2

   Actually not. Google is your friend (but not definitive). PVC and "Great Stuff" foam is not to be used around PEX. Some solvents and other sealants should also not be used. Some foam is OK but it is not recommended that more than 2 inches be applied at one time because of the heat that is generated as the foam cures. Is this info correct? Who can say for certain. Why come to Fine Homebuilding for questionable advice. Get the exact chemical name of the foam that will be used and contact the PEX manufacturer.

1. 
   jlyda | Mar 02, 2020 02:05pm | #3

   You are right it does depend on the type of foam and thickness. The type of foam used by my provider is safe to use. They also blow in 2” lifts to not create a massive heat build up. We’ve never had issues with it. I had a brain lapse and forgot to think that your provider/supplier is different. Yes, always best to confirm with your insulator.

1. 
   suburbanguy | Mar 02, 2020 02:24pm | #4

   Best to confirm with tech support at PEX manufacturer/distributor. A foam company may potentially simply tell you what you want to hear.