attachimg dishwasher with water supply behind a wall

smleeFebruary 10, 2012

We want to install a dishwasher in a house that was built in 1950. There is no dishwasher there now. The dishwasher will be placed next to the sink & and needs to be hooked up to the hot water supply line. The water supply for the faucet is running up behind a wall (under the sink)to a wall-mounted faucet.

There is no direct access to the water lines under the sink so we have to cut open the wall

Our plumber thinks that the supply line is likely to be one vertical iron pipe. He suggested cutting the pipe and using a "g coupling?" to get hot water to the dishwasher?

He says that this method is not the standard way but it would work. Any thouhts on this-- is it risky for a leak or other stability problems?

Thank you for your help!

Thank you for reporting this comment. Undo

What is he calling a 'g coupling'?
If, as I suspect, it's a brass compression fitting, it would be susceptable to developing a leak at some future time. I wouldn't use it in an installation that was not easily and frequently seen.

    Bookmark   February 12, 2012 at 2:19PM
Thank you for reporting this comment. Undo

He is proposing a "T" G-coupling which uses neoprene washers to seal its connection to the piping.
These are not supposed to be enclosed within the wall cavity.
Given the era of the houses origination, I suspect that it is on a raised foundation.
If this is the case, I would suggest that a separate supply be installed in the hot water supply line, under the house and brought up for the appliance.

    Bookmark   February 12, 2012 at 7:06PM
Thank you for reporting this comment. Undo

Open the wall, remove some pipe, add some new nipples and a T.

    Bookmark   February 13, 2012 at 1:26PM
Thank you for reporting this comment. Undo

Thank you everyone for their input.
Our plumber meantion that the main risk would be a leak and suggested that if we do install a dishwasher by this g-coupling method then we should have an access panel under the sink to monitor for leaks. I look under the sink often because that is where I store my cleaning supplies so would be able to check for leaks frequently. I'll keep the wall open since it's under the sink and no one but me looks there anyway
Snoonyb: unfortunately our house is on slab. The plumber looked into creating a separate line but it would require major cutting of walls, cabinets and tiles. More expensive work than I could afford.
Brickeyee: I hope it's that easy.

My main question is: is g-coupling a dishwasher too risky for a leak even though I'll be able to monitor it? Is this something that is done in the plumbing world?

    Bookmark   February 13, 2012 at 9:28PM
Thank you for reporting this comment. Undo

ANYTHING in a normally-pressurized main water supply that "requires monitoring" for leaks is huge no-no IMHO. Cut the wall, get in there and do it right or don't do it, IMHO. The likelihood of a leak may be low but consequences can be catastrophic, especially on slab where there's no place for the water to go except all over.

    Bookmark   February 14, 2012 at 9:01AM
Thank you for reporting this comment. Undo

"one vertical iron pipe"

He probably means galvanized steel.

While it can be moderately difficult to unscrew old galvanized steel pipes, it can be done.

Every plumber knows to use a second wrench to back up pipe so torque does not go to the wrong threaded joint.

About the worst that happens is a pipe tears off where it enters a female fitting.
Then you can either use an internal pipe wrench or remove more of the line.

A correctly made threaded joint (pipe dope and tight) works just fine.

    Bookmark   February 14, 2012 at 9:52AM
Thank you for reporting this comment. Undo

I would begin by getting a reputable plumber to look at the job;

First off, the only approved method of making connections on iron pipe is by means of NPT (national pipe taper) threaded fittings or in some instances they will allow welding the pipe(providing you have a welder that is certified as a pipe fitter.)

Next, A plumber can be held both civilly & criminally liable for any death, injury or property damage that arises from failure of his/her work.

Now consider this: In order to get a Plumbers License one must undergo a four year apprenticeship where you must work 200 weeks under a master plumber & report your work history to the state apprenticeship board (any week with less than 40hours doesn't count). In addition to working under the master you must also attend an approved college or technical school night school and complete a state mandated carriculum on plumbing. Once you have a diploma from the college or tech school, and a certificate of completion from the state apprenticeship board confirming your hours of service you are then invited to go take the state licensing exam. You then pay anywhere from $250 to $500 non-refundable testing fee and they will schedule you for a time and place to take the exam. You will also be informed that the test is an open book exam and you are required to bring a list of reference books that generally cost another $600.

Any reputable plumber will examine a job and figure out a "code approved" solution. In this case, if the pipe in question is an iron pipe and not accessible without major demolition they may locate another source for the water line to the dishwasher, but I can assure you, no reputable plumber is going to risk loosing his/her license and serious property liability problems merely to save the homeowner a few bucks.

The fact that he is telling you that you will need an access panel so you can keep an eye on the work is a dead giveaway that this fool is not a reputable plumber and I don't care how many years he/she may have been in the business. We simply don't need that type of ppl making it look bad for real plumbers.

    Bookmark   February 14, 2012 at 3:18PM
Thank you for reporting this comment. Undo

Sounds like I should talk to another plumber for a safer solution. Will do. I hope he'll be able to come up with a code-approved method otherwise I suppose I'll be hand-washing dishes for a while :) Thanks for all your help! Leigh

    Bookmark   February 15, 2012 at 6:21AM
Thank you for reporting this comment. Undo

Another alternative is to open the wall from the other side, which should allow for more freedom of access than preforming the alteration inside the sink cabinet.
Piping in the configuration in your dwelling are supported by being strapped to blocking and verticle wood members, which add an additional repair configuration.
A quality repair will appear as seamless.

    Bookmark   February 17, 2012 at 1:13PM
Sign Up to comment
More Discussions
fleck fusion high flow metered water softener
Our Culligan has died and we aint too heartbroken about...
Costco Water Ridge Dual Flush -- Need reviews
Any more reviews on the dual flush Water Ridge toilet?...
Improving water pressure to outside spigot
I would like to improve the pressure and flow rate...
what brand water softener
have 2400 sq ft rancher on town water. do not have...
Electric Water Heater Problem
I have an electric water heater; about a month ago...
Sponsored Products
Black 10'' Bread Knife
$9.99 | zulily
2-Pc. Small Red Rim Bowl Set
$19.99 | Dot & Bo
Blanco Aerators & Air Gaps Deluxe Air Gap in Stainless Steel 440035
$42.25 | Home Depot
Windster 36W in. WS-28TB Series Wall Mounted Range Hood - WS-28TB36
$573.00 | Hayneedle
American Standard Sink Basin Racks Prevoir 15 in. Square Kitchen Sink Grid in
Home Depot
Lenox Pearl Beads Salad Plate - Set of 2 - LNOX1665
$49.00 | Hayneedle
Lime Spaghetti Jar
$11.99 | zulily
Denby Double Dip Mug - Set of 4 - DENB197
$67.96 | Hayneedle
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™