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bradkerbick · Feb 12, 2009, 03:11 PM

But, I want to add a bath tub in my concrete basement. How the heck do I hook the drains? What is this Dap-out? I have a toilet drain and a 1 1/2 sink drain. That I can tie into. I have to jackhammer the floor but then what?

Thanks in advance a tired frustrated Dale today.

ballengerb1 · Feb 12, 2009, 03:16 PM

Actually you need to jackhammer the floor leading over to the wall where your sink likely drains. You must locate the main drain line which likely goes verticle inside the wall. You tap into that line belowe your current floor. The dap out is the opening in the floor that allows you to arrange your tub drain and trap. Its usually a 12x12 box cut out in the floor.

bradkerbick · Feb 12, 2009, 03:52 PM

Ok so I get my drain and Trap arranged in the dap out and tied into my sink drain ( not the toilet drain). Then I cover with mortor? Then how do I tie my tub to the drain and overflow?

Thanks

massplumber2008 · Feb 12, 2009, 05:11 PM

Hi Brakerbick...

If wet venting (would need to ask a local inspector) is allowed in your area you may be able to chip the concrete floor up over to the 2" sink drain underground (all pipes are supposed to be a minimum of 2" underground) and connect the shower drain pipe into the sink drain pipe.

Here, you will expose about 12-18" of the sink drain pipe and then you will use a reciprocating saw with a bi-metal blade to cut out SAY 12" of the 2" cast iron pipe and install a 2" PVC wye fitting. You will need special 2" cast iron x 2" PVC shielded transition clamps (see picture) to make change from cast iron to the PVC wye fitting for the tub. Then you will lay out the pipe/wye fitting as drawn below, add a 1/2" to the overall length (in this case, 12.5") and then lay that out on the cast iron pipe and cut the pipe. Then you will install the clamps, FLIP the rubbers back on themselves and then drop the pipe/wye fitting into place and then FLIP the rubber sleeves back to join the pipe and then slide the SS clamps over the rubber sleeves and tighten all up. You can now run a PTRAP over to the tub area as long as the trap won't be more than 6 feet away from the sink drain.

If tub ptrap is more than 6 feet away then you will need to add an 1.5" vent just before the tub ptrap and that vent will need to connect into the sink vent at about 48" off the finish floor... ok?

If wet venting is not allowed in your area then you will simply need to run the individual vent as mentioned already.

You will not cement the dapout box. Instead you will use this space to connect the PTRAP to the tub waste and overflow assembly from the tub... see picture You will connect to this tub waste and overflow assembly using an 1.5" PVC desanco fitting (compression x PVC fitting) or an 1.5" PVC female adapter and install that into the PVC ptrap.

Let me know if need more here...

MARK

bradkerbick · Feb 12, 2009, 05:17 PM

Ok so now I have a drain for the tub. I set the tub in place and with the tub in place how do I make that connection? Cut a hole on the wall to the room next to the bathroom to be able to reach under the tub? I do lots around my house, just never worked on a tub I could not get to the bottom of from the floor below.

Thanks Dale

massplumber2008 · Feb 12, 2009, 05:24 PM

Hi Dale...

Read post #4 and then let me know if you have questions... ;)

You will definitely need to cut an access panel in the room behind the tub!

MARK

bradkerbick · Feb 12, 2009, 05:35 PM

So in you last pic in post 4, The very bottom open end of the pipe is what ties to my drain line and this I can now reach through the hole in the wall?

Thanks

massplumber2008 · Feb 12, 2009, 05:36 PM

Correct...

But the tub drain could have a threaded tailpiece as in 1st pic... use desanco fitting here, or you could eliminate the threaded tailpiece and simply install a threaded female adapter onto the threads of the tub wase and overflow assembly itself... ;) (as in 2nd pic.).

If use the threaded tailpiece be sure to use pipe dope on the threads... ;)

You can reach all of this from behind at the access panel.. as long as pipes are in the box... ;)

MARK

bradkerbick · Feb 12, 2009, 05:49 PM

The tub drain kit bought already is ABS, Is this OK?

Thanks for all the answer's Mark. The thing I was missing was the hole in the wall lol.

massplumber2008 · Feb 12, 2009, 05:56 PM

ABS drain is fine.. ;)

Let us know as you go along... glad to help!

bradkerbick · Feb 14, 2009, 04:06 PM

Ok 5 hours of work today. I jack hammered my floor, found a tie in spot in my sink drain. There was a shower down here before and I was curious what the drain were like under there so I jack hammered and extra 2 feet to see. There is a 3' p trap. Once I saw this I want back to tie in my drain line, but had to jackhammer more room to get my line to move enough to get my 2x2x1 1/2 tee installed. All good I have a drain for my tub in a framed in Dap Out. Tomorrow I back fill and pour concrete.

Thanks Dale

bradkerbick · Feb 14, 2009, 04:19 PM

One more thing, Between my concrete and the sand below was a layer of plastic. I guess I need to repair the plastic I disturbed?

Thanks

massplumber2008 · Feb 14, 2009, 04:22 PM

Glad you will be up and draining soon Dale... ;)

I did, however, say that you should install a 2" PVC wye fitting (post#4). Then that 2" pipe runs over to the tub and is reduced to 1.5" at the inlet or outlet of the trap.

*shrugs*

Thanks for the update!

MARK

massplumber2008 · Feb 14, 2009, 04:25 PM

It certainly can't hurt to replace the plastic... ;)

bradkerbick · Feb 14, 2009, 05:58 PM

So will the tub just drain slower since I have 1 1/2 instead of 2" pipe?

Tha nks again.

massplumber2008 · Feb 14, 2009, 06:34 PM

Hi Dale:

Because you are using the lavatory vent as a WET VENT for the tub then with 2" the waste to air ratio allows the pipes to "self-scour" more effectively than in an 1.5" pipe... simply meaning that there is less chance that a clog will develop in the future... ;)

I'm sure you will be fine... many people have run 1.5" to tubs underground and never had an issue!

Up to you here.

Keep me posted.. ok?

MARK

massplumber2008 · Feb 14, 2009, 06:43 PM

By the way... you definitely want a WYE fitting here.

If use a sanitary tee fitting (see pic.) when you snake in the future you could end up snaking the vent (sink drain/vent) as often as you would snake the drain (sink/tub drain)... that make sense? A wye fitting forces the snake to go down the drain.

If you need to replace this fitting from a sanitary tee to a WYE then I say you replace all with 2" wye...

I wonder what the other plumbers here will think? Give these guys some time to chime in... ok?

Let me know...

bradkerbick · Feb 14, 2009, 11:32 PM

I did use a sanitary tee. The 2" drain I tied into runs horizontal. I rolled my tee over to a 45 Deg, and attached a 45 deg elbow ( with a "close nipple") to get my 90 deg, running perpendicular to the drain line I tied into and level with ground (Small down slope) Thing is I am just above the toilet drain which I have to stay on top of, so I am not sure how I could make the wye work. I do want to make sure I get this right the first time though.

Thanks