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-   -   Repiping with Pex (https://www.askmehelpdesk.com/showthread.php?t=263161)

  • Nov 3, 2008, 08:09 PM
    EPMiller

    b1s,

    I can't speak to the Tacoma plumbing codes, I'm on the other side of the country.

    As to the 2nd question, I wouldn't go as far as saying it is good practice, but pex will not readily rupture when frozen like other types of water supply tubing. Depending on where it is in relation to the heated space, you might be OK just covering it with a fiberglas batt laid lengthwise over the pipe. I would like to see it in the bottom half of the total insulation blanket. If it is suspend in air, then you don't have many options. If you wrap it, when it does freeze, it will take longer to thaw. If the water isn't moving, a little bit of wrap or foam sleeve insulation could be worse than none at all.

    EPM
  • Jan 5, 2009, 06:57 PM
    Stubits
    Sorry to revive this thread again!

    When running PEX vertically through a stud wall, how do you handle the PEX as it passes through the bottom or top plate? How big of a hole should I drill for 1/2" or 3/8" PEX? Is there a special type of clamp? At one point in our installation we will have 7 separate lines running vertically together? I know they should be supported regularly, but how is this usually handled with so many lines? Any suggestions or tips?

    Thanks!
  • Jan 5, 2009, 09:30 PM
    KISS

    The easiest way is pipe clamps and strut.

    See Barnhill Bolt Co., Inc., Fastener Specialist

    For a general idea.

    Browse the MSC Big Book

    Industrial Supply Equipment from MSC Industrial Supply with search terms "pipe clamp strut"

    Note that there are no dimensions and I don't think the pipe clamps work with the thinner strut. 1 -5/8 is the normal size.

    As for hole size, I'd say about 1/8" larger than the tube.
  • Jan 6, 2009, 05:06 AM
    Stubits
    This actually makes perfect sense now. Thanks!

    I am still concerned about the PEX running through the top and bottom plate. I know that PEX expands and contracts, right? So, is there any concern with it rubbing against the rough sur face of the top and bottom plates?
  • Jan 6, 2009, 06:29 AM
    KISS

    The design guide, p80 has some better options:

    http://www.toolbase.org/PDF/DesignGu...esignguide.pdf

    They say PEX has to be free to move. Wood, I don't think is considered a troublesome penetration. Metal, block, brick etc. should be sleaved.
  • Jan 6, 2009, 06:50 AM
    Stubits

    Excellent. Thanks so much!

    What does the guide mean when it says, "Vertical tubing shall be supported ... at the mid-floor guide between floors."?

    Also, not related to tubing support, but still related to repiping. The main water line coming into the house is a threaded copper pipe. How do I determine the dimension of the pipe to make sure I get the right connector? Is it as simple as measuring the outer diameter?
  • Jan 6, 2009, 07:25 AM
    KISS

    You need a support/clamp at both sides of the penetration.

    I'm going to take you here briefly:
    Difference between Pipes and Tubes

    This explains something about pipes and tubes. Things get complicated. Generally sweated copper is really a tube and not a pipe, so a 3/4" copper tube has an OD of 7/8". Refrigeration tubing is an exception.

    Pipe, however has a Schedule associated with it. Most is schedule 40. It doesn't matter if it's plastic or what material, a 3/4 Schedule 40 PIPE will be 1.050" inches in OD.
  • Jan 6, 2009, 07:39 AM
    Stubits

    On the vertical runs, where the tubing passes through the top and bottom plates, would something like this work well? I know it is meant for suspended runs of tubing, but it seems like it would work in this application as well.

    http://www.pexsupply.com/categories....D=859&brandid=

    Now, given that the water main is not sweated copper, but threaded copper, does it fall into the category of tubing or pipe?
  • Jan 6, 2009, 07:58 AM
    KISS

    Perfect support.

    You can't thread tube, so it's pipe.
  • Jan 6, 2009, 08:21 AM
    Stubits

    Ok, OK, OK, I think I am catching on now, at least a little bit. Makes sense. So, if I measure the OD of the threaded copper "pipe," I'll be able to figure out.

    Great!
  • Jan 6, 2009, 08:31 AM
    iamgrowler
    Quote:

    Originally Posted by Stubits View Post
    On the vertical runs, where the tubing passes through the top and bottom plates, would something like this work well? I know it is meant for suspended runs of tubing, but it seems like it would work in this application as well.

    http://www.pexsupply.com/categories....D=859&brandid=

    You really shouldn't need any kind of support when passing through an upper or lower plate.

    When passing vertically through a wall cavity, I generally fasten the line every two feet to an adjacent stud with a two hole pipe strap, usually only screwing one side of the clamp to avoid clamping the line to tightly so it can move naturally as the line expands and contracts -- If multiple lines are passing through, I will zip tie the other lines to the one I fastened to the stud.
  • Jan 6, 2009, 08:34 AM
    Stubits

    Interesting idea. Is it necessary to fasten it every 2 feet vertically? What is the benefit?

    Thanks!
  • Jan 6, 2009, 08:40 AM
    iamgrowler
    Quote:

    Originally Posted by Stubits View Post
    Interesting idea. Is it necessary to fasten it every 2 feet vertically? What is the benefit?

    Thanks!

    It is in my neck of the woods (horizontally and vertically).

    It is a cleaner installation and it keeps the lines from contacting the backside of the drywall as it moves.
  • Jan 6, 2009, 08:44 AM
    Stubits

    Great idea. I didn't realize they had the potential to move around so much! Thanks for keying me into that.

    I basically have to run 7 1/2" lines, is that much to wrap up together?
  • Jan 6, 2009, 08:48 AM
    iamgrowler
    Quote:

    Originally Posted by Stubits View Post
    Great idea. I didn't realize they had the potential to move around so much! Thanks for keying me into that.

    I basically have to run 7 1/2" lines, is that much to wrap up together?

    It shouldn't be too much -- Just make sure you aren't bundling hot and cold lines together.
  • Jan 6, 2009, 09:08 AM
    Stubits

    Hmm, good point! So, should I bundle all the hot together and attach them to one stud and then bundle all the cold together and attach them to another stud?
  • Jan 15, 2009, 05:11 PM
    CarlyTD

    Hi,

    I just finished replacing copper and galv pipes from the street to 2 baths, 2 kitches, etc.. So here is my 2 cents...

    1. I would size it as follows. 1" from the street to inside the house, Off the 1" line I would tee of 3/4" to any hose bibs, 3/4" to the hot water tank, and then reduce the 1" to 3/4" to the cold manifold. I would run a 3/4" hot from the tank to the hot manifold.. Then run 1/2" to each fixture.

    2. I would use Wirsbo ProPEX with the connection rings and expander tool. You can rent the tool for $25/day. I bought one off Ebay for $265 and sold it on Craigslist for $225 two months later.

    3. Sharkbites are great but they are not rated for ground contact.

    4. 30"
  • Jan 22, 2009, 12:05 PM
    Stubits

    Sorry to keep this thread alive, but many thanks to all who have offered advice and assistance.

    I am curious about different options for connecting the supply lines to the actual fixtures. Currently my galvanized steel piping has a 90 with a stubout where it connects to a right angle compression shut off valve.

    I have seen copper stub out for use with PEX, is this what is recommended? Are there ways to avoid using these and stick with pex all the way?

    Any thoughts or suggestions would be welcome! Thanks!
  • Jan 22, 2009, 01:17 PM
    KISS

    Gut feeling, having never worked with PEX.

    A fixture usually consists of a supply, a valve and a flex supply to fixture. I would not be a fan of everything "flopping in the wind", so to speak.

    The niceest looking, easy to paintain stub, in my opinion is the elbow with ears attached to a stud within the wall.
    To this a piece of threaded pipe. Can be a brass nipple or a chrome plated brass nipple depending on visibility. A cone or hinged estucheon is attached to the wall. Then the threaded angle stop attached to that.

    To make a really professional job, sleave the penetrations of the drywall with PVC.

    Follow where needed, pipe to sleave with fire caulk.

    The only place I can think of that would not require this is shower areas behind an access panel and, of, course outdoor hose bibs.

    Shutoff normally exist at the manifold, but it sure would not hurt to have one nearby when doing replairs.

    To give you an example, a bit weird, though.

    Shutoffs for a bathtub behind a large wooden access panel where a shelf would have to be emptied and the stuff on the floor of the closet would have to be emptied as well to gain access.

    My valves are not directly behind the panel. They are in the ceiling below (suspended ceiling in basement).

    They can be turned off in the basement in an emergency, They can also be turned off from inside the access panel as there is access to the valves.

    When I replaced the Lavatory shutoffs. It was the long chrome plated soldered angle stop with the pipe versions, I took the opportunity to install secondary shutoffs downstairs in the ceiling with drains. At that time I anchored the pipes in place so the valves were relatively immobile.

    I did the same for the toilet supply except did not replace the valve.

    While I was at it, I piped the connections for a recirculating system.
  • Feb 8, 2009, 08:06 PM
    Stubits
    Just out of curiosity, why sleave the drywall penetrations with PVC?

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