Is there a proper way to route PEX through attic?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by CountryBumkin, Oct 7, 2009.

  1. CountryBumkin

    CountryBumkin New Member

    Messages:
    86
    Location:
    Orlando, FL
    I have PB in my house. I'm going to be repalcing it with PEX at some point in the future (either when it leaks or for re-sale purposes). I have seen the picturers/diagrams of various routing methods regarding Home-Runs and Trunk-Branch plumbing. Which ever way I go I know there will be alot of lines running parallel through the attic. BTW - My existing PB pipe is under the slab.

    When the PEX is run throug the attic does it matter if it is run along the floor or if it is run about 4 feet above the floor along the verticle truss supports. I think most plumbers would run along the floor like the electrical wiring is done, if it is new construction. Since my house is built, there is insulation on the floor and it woul dbe difficult to run it that way (note that most of attic does not have a floor, just insulation between ceiling joists).

    If there a code specifing how the PEX plumbing should be run? Or is it just run the most convient and/or asthetic way?
    Thanks
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,647
    Location:
    Cave Creek, Arizona
    Pex

    Usually the most convenient way, although I would suspect that fastening it to the vertical members would make it a nuisance to moving through the attic. Aesthetics and PEX do not usually occur in the same sentence.
  3. jastori

    jastori New Member

    Messages:
    118
    Location:
    Illinois
    Ideally, in the attic, you would want to run the pipe as close to the ceiling as possible (below the insulation). I suppose you don't have freezing issues in FL, but if you run it above the insulation, the water in the PEX will heat up more than if it is run close to the ceiling.
  4. CountryBumkin

    CountryBumkin New Member

    Messages:
    86
    Location:
    Orlando, FL
    Good points.
    If I run it above the insulation I would run an insulated cold water line (the hot water line would only get hotter up there). I think I could run it parallel to the "path" I use to get from one end of the attic to the other. I saw insualted lines on the Wirsbo website.

    I think i would like to have it below the insulation but it would be a huge job to take up all the insulation (i both batt and blown). So, since there are no objections - above is the plan.

    Thanks for your help.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,647
    Location:
    Cave Creek, Arizona
    objections?

    Why would we have any objections? It is YOUR house, and WE are not going to have to work in your attic.
  6. austintx

    austintx New Member

    Messages:
    27
    Location:
    Houston, TX
    I have thought about this as well. My lines will be running perpendicular to the joists, so going above the insulation is about my only option. Since I will have several runs of PEX going from the manifold to the area of use, I have thought about taking some thin walled, large diameter PVC (the cheap sewer line stuff), and making a couple of cuts down the length of it to create a C shape to lay all of the lines in.
  7. Earnie

    Earnie New Member

    Messages:
    25
    Location:
    At Home
    I'm no expert on Pex or plumbing. Actually I'm getting questions answered in another post.

    One of my concerns with the Pex under the insulation would be someone stepping on the pipe and breaking it. I've been in attics before and it's easy to miss the rafters when stepping from rafter to rafter. I know of instances where a foot missed the rafter and went through the sheet rock ceiling. That plus water pouring into a room from a broken Pex line would make for a bad day.

    You might consider posting a large sign in the attic entrance warning of the hidden Pex water lines under the insulation.
  8. CountryBumkin

    CountryBumkin New Member

    Messages:
    86
    Location:
    Orlando, FL
    Your both right. I could run it below the insulation in a location that is not easy to walk through so stepping on it wouldn't be an issue - but my access to that space would be tough too. Since there are no expert opinions/advice (objections was not a good word) or code requirements not to run above floor, I'm going to route above the flooring.

    I was thinking of nailing up some 1/2 plywood in 10 or 12 inch strips nailed to vertical trusses. Then I would run parallel red and blue PEX neatly fastened to the plywood from one end of the attic to the other. Once I get to the bathrooms and kitchen the PEX lines would drop into the wall studs. I get very focused on aesthetics sometimes (I think a quality job should look like a quality job) but that would require a lot more time in the attic.

    I think your PVC method would be easier - but it wouldn't be as pretty. But (my) comfort and speed trumps pretty.
  9. davesnothome

    davesnothome DIY Member

    Messages:
    53
    Location:
    Ontario, Canada
    Just some advice on running the pex. I have already run some in an area where its easy access....that stuff is a pain to uncoil and run neatly...its like a wrestling match sometimes. What I found easy, and usefull in confined areas, was to buy some of that cheap 3/4 grey PVC in 12ft lengths...its cheap. You can feed the 1/2 pex through it really easy....keeps it protected as well as a nice straight run. Lay your PVC and clamp it in place....then use the 90 degree elbows where it turns and runs down the walls. Then just guide the pex into the PVC and slide it in...so easy, protected, and neat.
  10. Earnie

    Earnie New Member

    Messages:
    25
    Location:
    At Home
    Gray schedule 40 pvc is used for electrical wiring not water.

    Just to make the point, here is something I know for a fact happened.

    A company was installing exterior pan and tilt video cameras at a hotel. It ran the 110v electrical wire for the P&T motors through white schedule 40 pvc which was buried in the ground.

    Later, another company doing work in the same area noticed the white pvc and had hotel maintenance shut off the water to the sprinkler system, thinking the white pvc they encountered belonged to the sprinkler system. Their trencher cut through the white pvc and made a nice shower of sparking electrical wires until the breaker tripped.

    Good thing no one was hurt.
  11. davesnothome

    davesnothome DIY Member

    Messages:
    53
    Location:
    Ontario, Canada
  12. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Pex must be secured every 32" horizontally,regardless of it.s location
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