Plumbing: Plastic or metal?

[Norton]

To start with, let me just say that doing plumbing work sucks.....massively....OK I feel better now.

A series of unrelated but imminent plumbin issue facing us.  

1.  I'm replacing the sink and faucets in the extra bath and noticed that the metal trap pipe was cracked, which means that it needs to be replaced.  It's the silver metal pipe and has obviously corroded over the years due to the acidic well water (we put a water conditioner in when we moved in so no longer an issue).    The drain coming from the sink is gray plastic so it will meet up with any kind of trap.  Should I use a PVC or metal trap as a replacement?

2.  Just to add confusion to #1........when I disconnected the trap to remove the sink top and drain, the whole trap assembly slid to the bottom of the vanity cabinet.  My first reaction is that I pulled the drain loose from the pipe in the basement and it slid to the side and fell.  Not the case apparently.......it looks like they took the drain pipe from the sink and just slid it inside of the larger copper pipe in the basement without any sort of compression or nut fitting.  I'm hesitant to repair this as it means tearing the vanity out of the bathroom to access the copper pipe from the basement.  It's been in this condition for 40 years.....any real cause for concern?

3.  We're having the plumber coming in next week to give us an estimate on cleaning up the plumbing nightmare in the room downstairs that we are turning into a music room for us to practice in.  There are pipe running at crazy angles, some below the joists, some pipes that run for 10 feet and terminate (the previous owners relocated the laundry room).

The pipe is all copper except for two legs of that Quest pipe which is also going to be replaced before it bursts.

So....when I get him to write up the quote, do I want to use copper pipe again or should I just go with the PVC?  I want it done RIGHT.....don't want to think about it again.

It's no wonder that plumbers make as much money as they do......what a pain.

[Fly320s]

First, you'll be restricted by your local code.  Otherwise I would suggest using copper for pressurized pipes, such as water supply, and PVC for drains as they don't need to be as durable.

I have just about zero experience with plumbing, with one glorious exception.  

Our house is new, just one year old.  Local code allows, and the builder installed, PVC-type from the main city supply pipe.  He installed copper in the house.  We had numerous leaks and breaks in that PVC pipe in the first year, mainly due to poor installation techniques.  One design flaw in the installation had the pipe making a horizontal 90 degree turn to enter the foundation and then a vertical 90 degree turn to join the copper house piping at the shutoff valve.  The water pressure kept causing seperation and breaks at those joints.  Even after two refits/realigns, the PVC pipe was still seperating and breaking near the foundation.  We also had leaks along the 130 feet of length of pipe from the main supply (it had numerous connections).

Primarily, the problems were installation errors by incompetent plumbers, but even different plumbers using the "good" glue couldn't keep the PVC joints together.

Finally, I had enough and had the entire supply line replaced with copper with a protective sleeve over it.  Not a single problem since then.

Yes, copper is expensive, but it is more durable and probably better suited to certain applications such as the pressure lines.  If you do need to fix a bad connection joint, I would guess that copper is much easier to re-solder as opposed to breaking, recutting, and regluing the PVC.

It looks like you're working with drain lines only, so the above info might not be of use to you.  If that's the case, I think you'll be fine with PVC.  Large diameter copper probably will cost a bundle.

For your #2 issue above: get that fixed.  If that pipe ever backs-up it will leak into your basement.  Not to mention that it will let odors into the same area.  Is it accessable from the basement?

HTH and good luck.

[Art Eatman]

I did all the plumbing by my lonesome when I built my house in 1993.  So far, no problems with the PVC and the flexible connectors from pipe to faucet.  All the drains are PVC, as well.

Art

[Norton]

Thanks guys.

Some of the aforementioned nightmare in the extra room is supply so it sounds like copper is the ticket there.

That drain/trap deal does concern me, and no it's not accessible from the basement as far as where it currently makes the connection.  Since the plumber is coming Tuesday to bid on the "nightmare" I may just ask him to correct that too.  I'll patch it to get us through the next few days since we're having people over tomorrow.  Uggghhhhh.......

[BozemanMT]

Pressure side, copper only.  Hard copper pipe, no flexible crap.  and all fittings are threaded or sweated.  no compression fittings.  All compression fittings leak, it's just a matter of time

Drain side.  PVC, compression fittings are fine here. (although glue is better)

[Paddy]

Compression fittings pretty much suck for drains, too, in my experience.  One bang with a wastebasket or something you store under the sink and they leak.

[Art Eatman]

Bozeman, the reason I went with plastic is the water here.  Very high in TDS as sulphates.  It eats metal like a kid on candy.  I get maybe three to four years out of faucet fixtures.  Heck, if I can get five years out of the stainless steel well pumps I feel lucky.

, Art

[kudu]

Norton, in the 60's copper drains was good way to plumb houses, cheaper and easier than galvanized screw pipe and small cast iron.  My house is all copper drains and vents, as well as my brother's.  I am a plumber, and as long as you can adapt to the copper with a good threaded adapter you're good to go.  As far as under the lavatory, plastic p-traps are the way to go, they don't rot out like the chromed brass ones do.  

As far as the drain in the lav cabinet, it needs to be fixed right, with some type of a trap adapter and a friction nut to make it seal.  Hopefully an experienced plumber will give you a decent quote and won't half-ass the fix.  Copper drains are VERY expensive to replace, adapt to PVC.

[Azrael256]

One quick thing about copper: make REALLY sure that you replace your sacrificial anode in the water heater if you use copper on the hot water side (which you probably do).  I'm sure Kudu, and anybody (like me) who has ever had a hot water pipe spontaneously leak in the middle of the length in July knows just exactly why.

[Norton]

Thanks again for all of the good advice.

azrael,

We currently have Quest pipe running to both sides of the hot water heater, which is one of the imminent things to be replaced.  Regarding the sacrificial anode (I typed that just like I knew what it was, which I don't ;-) ), the HWH is new as of two years ago......does this make a difference?

[Azrael256]

Yeah, it does.  The anode is inside the water heater, so you got a new one with it.  Just be sure to swap it for a new one every five years or so.  It'll last twice as long if you do that.

[Norton]

Yeah, it does.  The anode is inside the water heater, so you got a new one with it.  Just be sure to swap it for a new one every five years or so.  It'll last twice as long if you do that.

Cool...that's good to hear.  I'm a good owner to my HWH....drain it every June to get the crud out....I guess that's supposed to help the elements, right?

[Art Eatman]

Anytime you have dissimilar metals (iron and copper, for example) in a moist or liquid environment, there will be a slight flow of electrical current.  The current flow is from + to - or from anode to cathode.  This current flow carries molecules from the anode to the cathode, eroding the anode and plating the cathode.  (Chrome-plated bumpers, for instance).  The flow is from the lighter metal to the heavier metal.  copper is lighter than iron.

You don't want the copper pipes to "go away" from the inside, so you use a lighter metal as a "sacrifice".  It erodes instead of the copper.  Aluminum is commonly used.   Aluminum is lighter than copper.

The same sort of sacrificial anode deal is used with pipelines.  (Steel marine facilities/boats, as well)  The erosion there is from the metal of the pipe into the surrounding ground, from moisture in the soil.  That's why older pipelines, installed before the idea of sacrificial anodes, have failed.  The results can be catastrophic in the case of oil or gas lines.

Art

[benEzra]

For those out there with plumbing experience--is there a feasible way to convert a sweated fitting to a threaded one (threading the pipe or whatever)?  Our house has sweated copper plumbing on the pressure side, and I have a few shutoff valves that have failed in the open positions, meaning I can't shut off the water to the toilet without shutting it down to the entire house.  Is there a way to replace the sweated-on valves with screw-on valves?

[Azrael256]

Well, yeah.  You can just sweat on these little threaded adapter jobbies.  There's a name for them, but I forget just what it is.  You'll find them in the plumbing section, no doubt.  Also, consider replacing those old valves with one of these neato ball valves.  When I replaced my water heater, I had to shut off the whole house because of the same problem you had.  This new valve isn't supposed to freeze up from sediment.

[triggertime]

I have discovered a little problem myself... The bathroom sink was draining slow, so I took off the trap to use a hand-crank auger to clear the clog. After I snaked the line, and put the trap back on, I noticed a leak seeping out around the top of the rear nut on the trap.  I figured it was due to a worn slip nut washer, so I replaced it. No luck.

This perplexed me for about an hour until I found a pin hole leak on the back of the pipe that the lower end of the trap attaches to. This pipe (1 1/4in) goes from the trap into the wall via a hole in the back of the vanity.

How does this pipe, which is part of the p-trap, attach at the wall end? I have to buy a p-trap kit and redo the whole deal. But I have no clue how to remove that little pipe. Calling a plumber is out of the question right now... so any help/ideas would be greatly appreciated...

[kudu]

benEzra, If you don't want to sweat a female adapter onto the existing line I would recommend buying som compression adapters.  They have a brass ferule that squeezes onto the copper and the other side has a male or female thead that you can adapt to another material.  I would buy the male type and a threaded ball valve and replace or cut into the lines that have problem valves.


triggertime, the trap arm disappears into the back of the vanity cabinet usually behind a chrome eschutsean (trim piece), behind this is another trap compression nut that is on a trap adapter.   It's possible that it is deeper in the wall than it should be, you may have to get some longer type pliers to remove the old nut.  If you replace the trap buy an extra nut and washer to replace the one at the wall, as that set comes with the trap adapter in the wall and not with the new trap usually.

[triggertime]

kudu: Thanks for the explaination. There isn't a eschutsean, though. Just a crude hole in the back of the vanity. I can see the compression nut...this should be easy...I hope.