How do i insulate my PEX in my attic?


  #1  
Old 02-23-21, 04:13 PM
S
Member
Thread Starter
Join Date: Jul 2009
Location: United States
Posts: 238
Received 0 Votes on 0 Posts
How do i insulate my PEX in my attic?

I have run about 40 feet of PEX through my unconditioned attic for my bathroom remodel. Seems like it would be a pain and expensive to put foam tubes on each individual pipe, 10 of them to be exact. Would it work if I laid fiberglass batts over the pipes since they all run right next to each other? Would that qualify as insulated?

skeeter
 
  #2  
Old 02-23-21, 04:19 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 61,872
Received 1,480 Votes on 1,368 Posts
Not the best situation.

The PEX would need to be laid directly on the sheetrock and the insulation above it.
You need some warmth from the floor below to keep it from freezing.
 
  #3  
Old 02-23-21, 04:27 PM
S
Member
Thread Starter
Join Date: Jul 2009
Location: United States
Posts: 238
Received 0 Votes on 0 Posts
They run on top of and perpendicular to the ceiling joist. So you think it would be best to use the foam tubing and then also cover with insulation?

skeeter
 
  #4  
Old 02-23-21, 05:03 PM
Z
Forum Topic Moderator
Join Date: Sep 2005
Location: USA
Posts: 5,761
Received 189 Votes on 169 Posts
You actually want to insulate above the pipes more than the pipes themselves. You want the heat from inside the house to keep the pipes warm, and insulate above the pipes.

The best way to insulate in your case is to run batt insulation above the joists and above the piping. Leave the space between the drywall and the pipes free.

Just to clarify, CA, meaning California, not Canada, right? I wouldn't run piping in an attic in cold areas.
 
  #5  
Old 02-24-21, 05:14 AM
S
Member
Thread Starter
Join Date: Jul 2009
Location: United States
Posts: 238
Received 0 Votes on 0 Posts
Yes, California. Southern. 3200feet. We don't get too cold but it does dip below 32 occasionally with a little snow.

skeeter
 
  #6  
Old 02-24-21, 05:25 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,081
Received 867 Votes on 798 Posts
For your piping in the attic use only continuous runs of PEX with NO fittings. PEX tubing can withstand freezing very well but fittings can not.
 

Last edited by Pilot Dane; 02-24-21 at 09:09 AM.
  #7  
Old 02-24-21, 07:28 AM
S
Member
Thread Starter
Join Date: Jul 2009
Location: United States
Posts: 238
Received 0 Votes on 0 Posts
Continuous runs. Did that. It looks cool up there. To bad people will never see it.

skeeter

 
  #8  
Old 02-28-21, 04:46 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,453
Received 131 Votes on 120 Posts
I suggest that you dig out the insulation in the joists and directly under the entire length of the PEX pipes and all the way down to the ceiling below. Leaving a strip of empty space about 6 inches wide under and following the route(s) of the pipes. . For loose fill insulation, staple cardboard strips to the joists to keep the insulation from falling into the empty spaces. Then put the batt on top of the joists, pipe, and all

Optionally put just a half round of pipe insulation on the top side of the pipe.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: