Gimme PEX education

My biggest problem with PEX is not that it’s plastic its how it has to be done where I live at. Yes my hourly rates goes up when I install it because of the issue of I must stand be find my work.

I would try to sell more people on using PEX as long as they didn’t know about the manifolds. They make life hell for installing and I don’t see how they help to much compared to a properly installed copper layout. If I could just run the 2 3/4†runs and T off to 1/2†for everything it would not be bad. if you have a manifold system and you try a T off the customer wants to keep it a manifold system (so your out of luck).

Gary Slusser said:

I'm not a plumber but anyone should be able to run a piece of PEX from a tub/shower/sink back to the water heater.

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For a hot water recirculation system using the manifold system you would be running 3 cold lines and 4 hot lines to a bath room. But now you need on both of the return lines a check valve before it goes into the return manifold. With PEX so far I don’t know how not to set them up with out using a pump. So 7 PEX runs to a bath room hmm looking good.

There is a section in the code book that talks about uniform appearance and needs clips every 20â€. So now on the inspection everything must be straight; you can’t bend it you must use 90*’s and 45*s.

*** I should quote my self to death and re quote Gary but if read and not taken out of contest then I have now answered everything.

*** has anyone run some numbers on labor and materials for installing a PEX (must use 90*s and manifolds) –vs- copper 2.5 bath house with a hot water recirculation system. They way I’m looking at this its all down to how much it cost to do the job. If some one sits down to do it I want to see the parts

I wasn't aware of 'your' support it every 20" code, never heard of that; obviously the people with manifolds that speak to me don't have the (silly) code....

I don't know much about hot water recirc systems and maybe this is totally wrong but, I visualize a hot line teed off the main hot line coming from the heater to the manifold, run to the bathroom and teed off to each fixtures' hot side (what 2' before the fixture maybe?), and then back to the cold inkliet on the heater or on the heater drain. That's one 360* line to each bathroom instead of each fixture. You may or may not need a pump. Frankly I don't like domestic hot water recirc systems. Currently, fuel to heat water costs more than water... so operational costs are greater than the cost of water' which may be changing soon, especially out West. The systems can cause corrosion in copper and if the water velocity isn't controlled, in PEX too.

On each return line will need a check valve and depending on the lengths of the runs you will need flow valve.

I have not seen anyone do it with out a pump so far but the theory that works with copper I can not see working with PEX. It’s based of as the water cools and there is already motion in the pipes it will keep moving. It gets into heat risking and a bunch of other stuff. (I know I just backed my self into typing out how it all works but I don’t want to.)

But yes we have to support ever 20†and can not bend the pipe (we use a lot of 90* angles). There are a lot of strange codes where I’m at and I think they will spread around the country in a few years. Off subject; A lot of our electric codes we are using don’t come out in the NEC till 2008 I think (I don’t deal with them).

As far as the “T†off the line your right.
It would make more since to me to either;
-To run all the lines to the back of the shower and use smaller manifolds there.
-Run a single run down the main line like with copper and “T†off as needed.
Doing this would save time and money and would make life a breeze. It would make the whole hot water recalculating systems cost about 1/2 of the cost.

To my equipment I prefer PVC over CPVC, of course for cold water only, but where there is a code against its use inside a building, the next larger CPVC is fine. I also like PE pipe for service lines and well systems.