Damaged due to water shut-off/turn-on in 1920 condo building

I own a condo in a 3 story/6 unit building. Recently, one owner consulted a plumber, who said that we risk serious damage to our old plumbing system when we shut of the building water supply to do repairs. What can we do to minimize the risk?

Background: although most fixtures in the building have local shut-off valves, none of the bathtub/showers do (2 baths per unit). The building water supply must be shut-off for all repairs to this plumbing, as well as for the occasional job where the local shut-off is not sufficient/applicable.

Frequently, following building water shut-offs, there are changes in the water pressure throughout the building. We've been told by several plumbers that this is due to bits of corrosion in the system being moved around by the off/on. The last shut-off--a couple of weeks ago--to relocate a kitchen sink resulted in the complete loss of hot water in one shower, significant loss of pressure in another shower, and in a bathroom sink (3 different units, on different floors, both sides of the building).

We're looking into alternatives (e.g., adding shut-offs to the showers is an obvious place to start), but the fact remains that some plumbing work will require that the building supply be shut off. Other than the shifting grit, what can go wrong?

BTW--I'm the one who lost all hot water to one shower. I've already dismantled and cleaned the faucets and shower head, but there was no improvement.

Thank you

I would suspect that the primary problem is old obsolete galvanized supply pipes which are notorious for scaling up inside until they eventually plug up completely. How long that takes varies due to water quality, etc.
If it has primarily original 1920s galvanized plumbing, the only solution is replacement.
Good Luck!
Mike

Galvanized pipe was state-of-the-art in the 1920s, but it is steel and steel rusts and corrodes over time. Local water mineral contents vary from place to place, and that determines how long galvanized pipes will last, but anything over 40 years is a gift from the plumbing gods. The pipes can look just fine on the outside, but inside they can corrode to the size of a pencil. Underground pipes will rust out quicker than those inside because you have wet ground attacking it. I hate to be a bearer of doom and gloom, but I'd bet a bundle that your entire building is past due for re-piping.

Re-piping may be over-due, but it's just not feasible in the next year or two. (There is a major electrical project on the list.)

I'm wondering what type(s) of damage we are risking when we turn off/on the building water supply? Obviously, we're aware of the grit issue, which is a pain in the butt, but bearable. Could shutting off/on the water supply damage these old pipes or fixtures?

mckern said:

Could shutting off/on the water supply damage these old pipes or fixtures?

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Its very possible it could damage the very sensitive fixtures like pressure balancers or sensitive cartridges . The high risk is not being able to shut of the water in case of an emergency leak. In newer condos, the regulation is that every unit should have seperate and dedicated isolation valves per unit , as well as main vertical riser shut offs (hot and cold).

Your building is long overdue for an overhaul. I'm very surprised it has lasted this long without major plumbing issues.

I'll bet that you might incur major damage when the water is turned back on -- pressure surges could burst pipes whose walls are no longer at the design thickness, or threaded connections held together by rust. Remember, all the scale and "grit" you're seeing used to be pipe.

Regarding the possibility of not being able to shut off the water in an emergency--the main shut-off valve on our side of the meter was replaced a couple of years ago, which I assume provide some insurance against this potential problem.

It's clear we need to plan for a major plumbing project. Anything we can do in the meantime to prevent damage--other than minimizing the times we shut-off the water? For example, my dad always said to "ease" the shut-off valve open/closed and to keep a faucet open when doing repairs--does this make a difference?

Your dad was right. Minimizing the rate of change in pressure reduces the shock effect I alluded to above.

Yes it does. When filling a system do not just turn the valve to full on and let it rip. Crack it and let it fill slowly.
His advice of keeping a faucet open probably relates to soldering pipe and/or draining down.

When a plumbing system is bled down, you can get all sorts of vibrations as you open a faucet to get water. The air and water can really hammer and loosen scale and crud inside of the pipes. As said, if you can just crack the main shutoff back on, and open a few valves in each unit it will fill back up less aggressively and dislodge less crud.

I live in a condo, and one of the major things I've been fighting is to build up the reserve account so we have money to do a repair when the time comes (we're now at about $250K, but the auditors say it should be closer to $400K; it was about $75K when I started bitching, so we've made progress). It's a tough sell, as everyone seems to think they won't be there when 'that' time comes, so why pay for it now? It really hurts when you have to hit them up for an assessment. Much better to have it socked in the bank. Think about paying yourself, just like when the cable rates go up...you just bite the bullet and pay it.

piping

One thing you could consider, and your system may be a prime candidate for it, is descaling the pipe and an expoxy relining. Much less than repiping, and should be satisfactory for many, many years.

mckern said:

I

BTW--I'm the one who lost all hot water to one shower. I've already dismantled and cleaned the faucets and shower head, but there was no improvement.

Thank you

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Old galvanized pipes can be hell to mess with ....
and its very irratiateing when the lines clog up and totally stop up you hot water......


you say you have messed with your faucet but could not get any more water pressure onthe hot side........

Have you tried back flushing the hot side of the system
down to the water heater ???..


that will usually work ....

Thank you, all, for such a quick response and so much information.

I don't know what "back flushing" is, but I'll find out and give it a try.

Also, never heard of the epoxy option, but I'll pass that info on to my neighbors.

We're working on that reserve fund. Fortunately, we're a cooperative group and everyone supports the idea. Re your short-sighted neighbors who fear they may not be around when the reserve fund is tapped--around here, a healthy reserve fund is a selling point in the condo market. I'll bet that's true most places.

Water On/off

Google ; Pipe Relining On The Net
Basic What They Do Is Take The Pipe Apart At All The Faucets And Fixtures And Run A Sand Blasting Compound Though And Then They Run A Epoxy Coating Though The Inside Of All The Pipes;
Very Little Walls To Be Opened Compared To A Regular Repipe

Macplumb 777

Master Plumber

Seems to me if you have to disassemble, treat the pipes, then reassemble you'd have a lot of labor involved, and the epoxy treatment will sure cost something. I really don't know too much about the process, but I'd be willing to bet there would be problems with broken pipe and bad fittings when you go into the disassembly of the galvanized. I wonder if Pex might be a better alternative. This is meant as a question, not a suggestion.

I'm not a pro plumber and I know little to nothing about this sandblasting and epoxy re-lining, but I cut my teeth on old galvanized pipes when I first began DIY plumbing at age 11 more than 54 years ago. Our home was plumbed with it, of course, and it was old back then. Every time I ever took anything apart, it broke something down the line.
I can't see how this sandblasting and epoxy stuff will work on 87-year-old galvanized plumbing. I bet that it will blow or break apart or plug more than it fixes in this instance. Just my guess.
Mike

sandblasting pipes

I got a video on it, they tried to sell me a franchise....
at one of the trade shows..

The video showed homes in California being repaired with the epoxt coating.......

even in their video they claim that if the pipes are weak
or totally obstructed, it may either blow a hole out
the side of the copper or simply not work...

then you got to find the problem and replace the pipe anyway...

the epoxy coating is very thin. and really looks like a band-aid....

and if the copper or galvanized is paper thin,
how long it lasts is anyones guess.....


I was not too impressed....


I would prefer just doing it right the first time

the guy you find that claims he can do the epoxy blast
will probably not come back next year....

Who pays for damage to other units because of shut-off?

I need to shut the main off to repair my own shut-off valve and a faucet in my unit. The building is over 80 years old. The management company is hinting that I will have to pay for any damage to other units caused by the shut-off. Is that right?

Maybe, maybe not. I would pay for either a) a lawyer to explain the details to you, or b) a professional bonded/insured plumber who has his own lawyer.

master plumber mark said:

I got a video on it, they tried to sell me a franchise....
at one of the trade shows..

The video showed homes in California being repaired with the epoxt coating.......

even in their video they claim that if the pipes are weak
or totally obstructed, it may either blow a hole out
the side of the copper or simply not work...

then you got to find the problem and replace the pipe anyway...

the epoxy coating is very thin. and really looks like a band-aid....

and if the copper or galvanized is paper thin,
how long it lasts is anyones guess.....


I was not too impressed....


I would prefer just doing it right the first time

the guy you find that claims he can do the epoxy blast
will probably not come back next year....

Click to expand...

I agree Mark! Well stated! I'm surprised the epoxy doesn't cause something like tumors on lab rats or, something like that in California!

The process and verification of proper coating to me falls somewhere between "smoke and mirrors" "rattling chicken bones" & "sticking pins in dolls."