Re Plumb with Pex

[digitalplumber]

Remodeling an older home my son bought. This is what it looks like:

So if you look on the right side you will see the 2 bathrooms. We plan to start remodeling the one at the top of the page first. My thoughts are to complete it with new lines, maybe pex, and work towards the second bath and temporarily hooking it in to the exisiting supply (cold and hot).

What do you think?

 

[mccmech]

I think that if you are going to remodel 1 bathroom at a time you don't need to re-connect the demo'd bathroom to the water system until you are ready to test the water supply lines & valves. If you demo the bathroom with the shower first, merely shut the house water off, cut the trunks that feed the bathroom with the shower and install shut-off valves to isolate that bathroom. Now you can have the rest of your house up & running while you continue the current project. I would suggest that, when you shut the house water off to isolate the bathroom with shower, you might want to put isolation valves in for the bathroom with tub also. That way, when you start that project all ya have to do is turn off the valves to that particular bathroom. As far as using pex I would advise you of this: you will need to replace the t/p relief valve on your water heater. The plastic water lines have lower tolerances for both temp. & pressure. Best of luck with your very ambitious projects.

 

[johnjh2o]

I think that if you are going to remodel 1 bathroom at a time you don't need to re-connect the demo'd bathroom to the water system until you are ready to test the water supply lines & valves. If you demo the bathroom with the shower first, merely shut the house water off, cut the trunks that feed the bathroom with the shower and install shut-off valves to isolate that bathroom. Now you can have the rest of your house up & running while you continue the current project. I would suggest that, when you shut the house water off to isolate the bathroom with shower, you might want to put isolation valves in for the bathroom with tub also. That way, when you start that project all ya have to do is turn off the valves to that particular bathroom. As far as using pex I would advise you of this: you will need to replace the t/p relief valve on your water heater. The plastic water lines have lower tolerances for both temp. & pressure. Best of luck with your very ambitious projects.

There is no reason to replace the T&P valve. There there to protect the heater from a catastrophic failure. Plus the T&P valve has absolutely nothing to do with the heater temperature or pressure. Some of your other points a well founded. Sometimes giving the wrong advice is worse then giving none.

John

 

[mccmech]

There is no reason to replace the T&P valve. There there to protect the heater from a catastrophic failure. Plus the T&P valve has absolutely nothing to do with the heater temperature or pressure. Some of your other points a well founded. Sometimes giving the wrong advice is worse then giving none.

John

Maybe you don't have to do that in your state. In New Jersey when you use plastic water supply material ( pex, cpvc, even poly supply lines ) you must replace the t/p relief valve with a reduced temperature/pressure relief valve. And I'll repeat "The plastic piping has lower tolerances for heat & pressure than copper does". So while I do in fact understand the purpose of the t/p relief valve, the code authorities understand that what is the point of having a relief valve that will only blow off at 210 degrees while your plastic supply has melted & is pouring water throughout your house at 190 degrees (arbitrary temp # for plastic piping used to make point). Take a look at the ratings of your water supply material sometime. At any rate, the o.p. is looking for input. I will gladly try to help someone out, thinking of their safety also. Your approval or disapproval of my input is of no consequence to me.

 

[digitalplumber]

Thanks for both suggestions and help.

What are your feelings toward Pex type piping? Sure seems like it will be easy, but time consuming to do?

Is there anything you would use instead?

Appears that the galvanized is run on top of ceiling rafters, wo you run the plastic type pipes any differently?

 

[mccmech]

I personally would run the pex before I would run CPVC. CPVC tends to get brittle & crack, plus you are using glue joints which may be subject to failure. Short of using copper, which any professional would suggest, I think pex is a very viable & budget-conscious alternative. The manufacturers make male/female thread x pex adapters to transition from your present supply material. There are also solder x pex adapters available, depending on your particular supply material. Anyway, you can buy the pex in coils to reduce the number of fittings needed for turns & such. The downside is that the tubing needs a wider turn radius for turns, so as to not crimp the tubing. You will also need to invest in a crimping tool to connect fittings to the pex. You can grab a combination 1/2", 3/4" crimping tool at the big orange box store for about $70. My final suggestion would be that if you use pex make sure to transition to the copper stub-out fittings. That way when you valve out your w/c & sink it will look more professional. Ya won't have the pex flopping around outside the wall with your valve attached. Sorry for the long-winded response.

 

[digitalplumber]

THanks and not long winded at all very informative!

Instead of wide turns, should I use 90's? I know it will cost more.



Thanks

 

[mccmech]

THanks and not long winded at all very informative!

Instead of wide turns, should I use 90's? I know it will cost more.



Thanks

It will look cleaner, so I would. The other point you made was that the existing lines run on top of floor joists. If at all possible, tack the new supply lines to the bottom of the floor joists. Those floor joists are probably notched from original install so I wouldn't want to fight removing the galvanized & I SURE wouldn't want to weaken the joists by drilling them for the new lines. If yer dealing with a basement that will be finished keep the new line close to either a wall or the main beam. That way you can build a soffett if necessary. Lastly, pex is less rigid than copper. Point being, copper gets tacked up every 4'. You will want to tack up the pex to every other floor joist just to keep it nice. Again, best of luck with yer project.

 

[digitalplumber]

Thanks, I was not sure about running the Pex or replacement thru the actual ceiling joists, this is a one story attic install.

It would be cleaner to cut in and run thru joists, but assumned that since it currently now is not, then code did not require it and because of the potential for weakening the joist.