I am trying to install a new sink in an existing island in the kitchen. The closest source of water is about 12 feet away. I have both hot and cold water there. Is it better to tap in the lines running under the concrete floor or run new lines again under concrete from the existing water source 10 feet away? How do I find the water lines under the concrete floor so I can tap into them for my new sink?

Any suggestions would be helpful?

Thank you
HughS

Hughs - Question- does the water ( BOTH) come up out of the floor anywhere under the sink ( Island )? OK if not you can talk to the contractor that built the house, he may have to get the plumber who plumbed the house involved, also there may still be a blueprint of the house down at city hall or the court house, where they get the permits for building the house. ( Now if you know how to witch for water , you can get right over the top opf the water lines,and know where to cut the concrete out at9 NOTE - A Willow , Peach, Cut off the tree like a big " Y '. you hold the stick at the ends of the forks ( They need to be about 2' long and the stright end at least 18". Believe it or not but the stick will bend stright down and you will be trying to hold it out stright.but cant. Good luck and GOD BLESS :: F.B.E. ( IT WORKS!! )

Hughs... definitely better to connect into the pipes UNDER YOUR KITCHEN SINK and then run new lines over to the island sink from there.

In my area, NO JOINTS/CONNECTIONS are allowed under the concrete floor for any reason/B]. And in areas that it is allowed they usually need to be brazed joints.. and you can't even find the water pipes...

Instead, you should probably run [B]flexible copper tubing (either TYPE K or TYPE L copper tubing can be used depending on where you live... need to call a local plumbing inspector and find what is used in your area for underground piping) OR you could run thermoplastic piping underfloor (such as a pex pipe) between kitchen sink and island sink.

The point here, again, is that all joint connections should be made under the kitchen sink... pipes should then be run 1 piece to island sink and then shutoffs and fittings added under island sink.

How are you getting the DRAIN pipe over to sink? And how are you planning to vent the island sink? Let me know would you...

Get back to me when you can...

MARK

Thank you MassPlumber. Your point is well taken. I spoke to two different plumbers and one of them was going to be looking for the pipes under the concrete and the other one said the same thing you suggested.

I plan to run a drain line from the existing drain to the new island sink.

Thank you for your advice. This is a great site.:)

HughS

Hi Hughs

How are you planning to vent your island sink?

Most codes require that you use an island sink vent system that is quite involved... especially if under concrete slab... check out the 1st picture below (island sink base would surround the pipes on right side of pic. And pipe at the left would connect into the existing sink vent at least 6 inches above flood level rim of the island sink (not shown in picture1)) and can CLICK on the attached image for another idea of how these get piped.

Otherwise, you may be able to install an air admittance valve (aav) like the 2nd picture below. It is piped out of the sink similar to the last picture.

You will need to check local codes in your area regarding island sink vents...

Let me know what you think... glad to help... ;)

MARK