[HandyFrank]

Had a few questions on pex, hoping a few of you guys with experience can shed some light.

I'm planning on updating some of my 1st floor plumbing that is accessible from the basement overhead. Pretty much just going to follow the trunk and branch system that is currently there and replace the old piping in nearly the same configuration. 3/4" trunk and 1/2" branching is what I'm replacing with pex. The house isn't configured well to adapt a manifold so i'm sticking with the trunk and branch.

90 degree bend vs. a brass elbow fitting
I have a few places where I can probably get away with a bend instead of cutting in an elbow fitting. I know too many elbow's will slow down the water flow, but was curious is there is a rule on how many elbow's are ok. I can use the bend supports in a lot of places, but I think it will install nicer and cleaner in some places if I just use an elbow fitting. I know the name of the game is less connections leave less points of failure. What is a common rule to follow?

Straight run pex tubing and expansion
I saw that lots of plumbers use straight run pex since it is a cleaner stall compared to the rolls that want to keep the shape of the coil and bend. I like the idea of straight runs so it keeps the install clean, but I know that pex needs some slack for expansion. In the past when using coil pex I've left a little slack in-between the tube supports, or added a bit of slack. How do you go about leaving slack in the line for expansion with straight run pex tubing?

Where to install shut off valves
Right now the old plumbing has valves all over the place in the basement piping, but not many upstairs below the cabinets. Is it common to install less valves in the main basement piping and then install valves underneath the sink in the cabinet? Or should I put valve's downstairs to allow isolation, and also upstairs in case I need to shut the water off quick from underneath a sink in the cabinet? Probably makes sense to install them upstairs under the sinks, and in the basement piping, but I was curious what is common.

 

[joecaption]

If you use the Pex hangers there made so there loose enough for expantion.
Really only need one main shut in the basement, shut of on the cold side of the water heater, one for the toilet, and one each for the hot and cold under the sinks.
I add shut offs for the outside faucets in the basement so if one needs to be replaced, shut off in the winter time or it leaks you can shut it off.
I also add a Tee and shut off so the lines can be drained if need be at the lowest point.

You really do not want to have to shut the whole house down to work on one leaking faucet.
In my own houses I add one for the hot and cold to the bathtub supplys and also use 3/4 supplys. Makes a big differance when showering.

 

[TheEplumber]

I'm attaching a link to detailed PDF on PEX. It's a pretty good read-
http://huduser.org/portal/publications/pex_design_guide.pdf
With that said- here are my thoughts and practices-
I use as few fittings as possible but sometimes you need them. As for the flow restrictions, I really don't know. But I install assuming some flow/pressure loss.
I almost always use sticks vs. rolls for the reasons you state. As for supports for expansion, the runs are not long enough to be an issue- plus the proper supports allow for limited movement.
Valves- You need a house shut off and valves at all fixtures(in the cabinets or at the wall), including the heater. Most tub/showers do not have valves but if you can put them in thats a bonus. If you want to isolate areas of the house too, you can. Hope that helps :thumbsup:

 

[joecaption]

The best prices I've seen on all the parts your going to need are on Pexsupply.com.
The prices on there valves where more then $10.00 each less them my local supply house.
Make sure to use stub outs where the lines stick out the walls where the valves are going.
http://www.bing.com/images/search?q...427CA1E0F06734CCB267D95D16452&selectedIndex=4

 

[HandyFrank]

I add shut offs for the outside faucets in the basement so if one needs to be replaced, shut off in the winter time or it leaks you can shut it off.
I also add a Tee and shut off so the lines can be drained if need be at the lowest point.

Good tips all around. I was thinking of using a lot more valves than I probably need now that I reevaluate based on your comments, i'll chop the number down based on where they make the most sense.

I'm attaching a link to detailed PDF on PEX. It's a pretty good read-
http://huduser.org/portal/publications/pex_design_guide.pdf
With that said- here are my thoughts and practices-
I use as few fittings as possible but sometimes you need them. As for the flow restrictions, I really don't know. But I install assuming some flow/pressure loss.
I almost always use sticks vs. rolls for the reasons you state. As for supports for expansion, the runs are not long enough to be an issue- plus the proper supports allow for limited movement.
Valves- You need a house shut off and valves at all fixtures(in the cabinets or at the wall), including the heater. Most tub/showers do not have valves but if you can put them in thats a bonus. If you want to isolate areas of the house too, you can. Hope that helps :thumbsup:

Thanks for the link, I already checked it out and read it from start to finish. I learned some good overall guidelines.

Guess i'll decide as I go where it makes sense to keep a 90 degree bend and keep the flow vs using an actual brass elbow connection. I'm already thinking that I have the room to use the plastic bend in a lot of places so i'll be keeping as much flow as possible.

I like the idea of using straight stick runs so it looks cleaner. My longest straight run is just under 20 feet for a hose, i'll plan to just pull the tube a bit and leave enough room for it to expand/contract slightly if it needs it.

Good tips on the valves. Already have a new main water valve installed. Now I think i'll put a valve under all sinks, and then put 1 or 2 so I can isolate certain sections of plumbing if I ever need too.

Connectors and Fittings
Anyone use the plastic pex fittings? I'm planning on using the brass ones only because they seem more sturdy and will probably last longer. Anyone against the brass ones? I know Zurn had issues in the past but I'm thinking that's all been cleared up.

 

[TheEplumber]

If I remember right, Zurns issue was with the "brass" used in the fittings. I use the plastic fittings. Tried to break one with a hammer and couldn't. A couple weeks ago we flooded a basement due to a 3/4" brass 90 that was cracked from the factory- got it that morning from the supply house- a $2500 fitting:furious: I'm sure it was just a freak accident. I wouldn't hesitate to use brass again but I'll look a little closer at my fittings. I don't use the bends either- I use copper stub outs and when going around corners I don't push the bend radius

 

[HandyFrank]

If I remember right, Zurns issue was with the "brass" used in the fittings. I use the plastic fittings. Tried to break one with a hammer and couldn't. A couple weeks ago we flooded a basement due to a 3/4" brass 90 that was cracked from the factory- got it that morning from the supply house- a $2500 fitting:furious: I'm sure it was just a freak accident. I wouldn't hesitate to use brass again but I'll look a little closer at my fittings. I don't use the bends either- I use copper stub outs and when going around corners I don't push the bend radius

Ouch, crazy a brass fitting was broken. I'm going to use the brass ones I think, will plan to inspect them thoroughly beforehand.

About the bends, I meant bends between the joists and stuff, not at the stub out areas. Thinking I can either use a bend guide, or just use the tube supports and keep the bends within the reasonable amounts. Want to get the job to look clean, so i'll take the time and spend the extra for whatever that will entail.

 

[jagans]

I have a home run system with a manifold. Turns are long turn sweeps. I think its the only way to go, as one fixture has little to no effect on another.

 

[HandyFrank]

I have a home run system with a manifold. Turns are long turn sweeps. I think its the only way to go, as one fixture has little to no effect on another.

Thanks for the tip. Unfortunately the house configuration won't allow an easy manifold or submanifold install, so I'm just going to replace the current configuration.

 

[jagans]

If I was you, and if my water was not acidic Id use copper, otherwise glued CPVC. I dont get the draw to Pex, unless its simply cost. Todays Great Idea is too often tomorrows disaster. Crimped fittings give me the .........................Crimps. :huh:

 

[jeffnc]

If I was you, and if my water was not acidic Id use copper, otherwise glued CPVC. I dont get the draw to Pex, unless its simply cost.

If you don't get the draw, I don't think you've used it.

All materials have their benefits and drawbacks. One drawback to PEX is that it's susceptible to UV light, so it can't be installed where the sun will hit it. Not a problem for plumbing a house, but of course it also can't be stored before use where sun can hit it.

Some cheaper brass fittings with too high a concentration of zinc can weaken due to dezincification over the years.

Again, if you've used PEX to install you'd realize how wonderful it is in some ways.

 

[jagans]

You are right on, Jeff, I have not used it. A lot of people really seem to like it though. Of course a lot of people really liked PB too. I actually have PB in my house, installed in 1993, and it is performing just fine, but I am on a well, and have a home run system and I have replaced all connections with shark bites. No problem so far, and the pipe itself is in very good shape, pliable etc. At the end of the day, its always the details that get you, isn't it?

 

[jeffnc]

I actually have PB in my house, installed in 1993, and it is performing just fine, but I am on a well, and have a home run system and I have replaced all connections with shark bites. No problem so far, and the pipe itself is in very good shape, pliable etc. At the end of the day, its always the details that get you, isn't it?

Actually there isn't anything wrong with PB pipe itself (as far as I know), it's all in the connections. So the reason it's probably doing well for you is that you've replaced all the connections! Sounds like a pain you went through, but hopefully you're good now. I've replaced a number of PB connections that I've found leaking. And when I go in crawlspaces, I see even more patches that others have fixed.

I personally haven't seen any problem with PEX pipe, although one time I did see a house with well water, and they had an expansion tank by their hot water heater, plumbed with PEX. There was a leak in a joint, and when I removed it I realized the brass fitting had corroded and weakened. I don't know if it was an older fitting that had too much zinc, or if the water was acidic, or what.

Of course you are right, they might always discover some flaw with PEX later down the road. It has been used in radiant heat flooring since the 1960s I believe without problems. That is not exactly the same as potable water piping, I understand.

Some of the things we consider "new" here in the US aren't always. Schluter products like Ditra and Kerdi spring to mind. It freaks me out how few guys in the trades have heard of it, let alone used it. When they have heard of it, they think it's new. It's actually 30 years old.

 

[jagans]

You are right. PB is still used in Europe as far as I know, and some of its attributes make it superior to PEX in certain ways. I re plumbed one bathroom with CPVC because I refurbished it, and put in a Jacuzzi tub. Used shark-bite couplings to adapt CPVC to PB. Same with Kitchen sink

I only had two splices in my PB system, all others were home runs. The splices were leaking, 2 sharkbite couplings, fixed.

2 curbcocks, replaced with ball valves to L copper, Sharkbite to PB Fixed.

I only have 1 bathroom and laundry to go, not leaking.........yet. WIll fix in spring if it makes it. Too damn cold now, unless push comes to shove.

 

[profcolli]

My plumber mentioned they have used sharkbite type fittings in France for 40 years with no problems, but there is a lot of resistance to them as a "new product" over here - even here in Quebec, which usually loves anything from France....

 

[jagans]

Well, sharkbite fittings depend on an O ring for integrity under pressure, and their teeth biting into the pipe to resist push out. Mine are installed so they cant push out, but there is still the O ring. I have to say that my confidence in properly soldered copper, and solvent welded CPVC is much higher, so when I go away for any length of time, I shut off my water main which is a one inch 1/4 turn Plastic Ball Valve. Maybe my confidence will increase over the years, but then so will the age of those O-Rings.