Insulation After Re-Pipe Before Drywall

[MarkSLSmith]

Hi folks,

My house was recently repiped.  I have rectangular holes in the drywall in many locations around the house.  The company does not restore insulation before drywall, so I want to insulate before they arrive for the drywall.  My plan is to only do this for outside walls.  Most of the new pipe (pex, of course) has pipe insulation around it. Maybe that's good enough to prevent freezing in this area (Houston), but the rectangular hole is still a thermal leak.

Should I try to press insulation between the outside walls and the pipes?  Between the pipes and the drywall?  Both?  With vapor barrier or without vapor barrier?  Is there any way I can shoot myself in the foot with this process?  Any other suggestions?

Any suggestions would be appreciated.

Mark

[Wipedout]

Just stuff insulation in there including behind the pipe

[MarkSLSmith]

Having a healthy respect that I don't know what I don't know, I was trying to keep it open-ended.  I do have 2 specific concerns.

1. Is it possible or likely that adding insulation, eg only on the inner wall side, could inadvertently make it easier for the pipes to freeze?

2. Is it possible to inadvertently create a situation that traps moisture, thus leading to mold or rotting of studs?

I think the answer to both of these is unlikely, but wanted to check.  Once the drywall goes on, any problems well fester unseen until they are well advanced.

Thanks,
Mark

[Roly]

Having a healthy respect that I don't know what I don't know, I was trying to keep it open-ended.  I do have 2 specific concerns.

1. Is it possible or likely that adding insulation, eg only on the inner wall side, could inadvertently make it easier for the pipes to freeze?

2. Is it possible to inadvertently create a situation that traps moisture, thus leading to mold or rotting of studs?

I think the answer to both of these is unlikely, but wanted to check.  Once the drywall goes on, any problems well fester unseen until they are well advanced.

Thanks,
Mark

? #1 Yes, because you are keeping heat from the inside away from the pipe if the other side is cold.
? #2  Possible  but unlikely for a patch unless if it adds another vapor barrier so  you create a area which moisture cannot escape.
Roly

[Large Wooden Badger]

Good news in having Pex is that you don't have as big of concern with freezing.  Brand new house here in DFW with Pex, during wintergeddon this year we had most of our pipes freeze due to incredible cold and lack of power for heat, but even though pipes froze not a one of them burst.

[Cabinet Monkey]

Don’t think south Texas homes get a vapor barrier on the drywall side.

I’d be looking in to spray foam.

[MT Woodworker]

I agree as I said earlier, spray foam insulation.

If you just push some insulation into the cavity it will eventually fall away..l