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Advice for plumbing connections for undersink cabinet supply & drain lines

Advice for plumbing connections for undersink cabinet supply & drain lines


  #1  
Old 05-16-16, 07:22 AM
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Advice for plumbing connections for undersink cabinet supply & drain lines

Hi everyone,
I'm looking for advice for best current method/recommendations for routing the Hot/Cold & drain supply lines through the undersink cabinet base - specifically we're getting new kitchen cabinets, sink & countertop.

I'm doing the tear out of the old cabinets and discovered that the Kitchen sink was installed with 3 holes drilled to just allow for the passage of the Hot/Cold supply lines and the drain line. In other words, the holes were drilled through the kitchen sink cabinet base and lifted over the two 1/2" copper supply lines before the valve stops were installed.
In order to remove the undersink cabinet, I have to either cut out the openings or remove the supply line valve stops to lift the cabinet base over the 1/2" copper supply lines.
I'm going to replace the (2) valve stops anyway but wondered what the current best practices are for connecting the supply lines through the undersink cabinet?

Appreciate your thoughts and suggestions,
greynold99
 
  #2  
Old 05-16-16, 08:40 AM
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On a new install, I do it the way yours was done, 3 holes just large enough to slip over the stub outs. On a redo, I just cut the holes a little larger so they'll slip over the stops and trap adapter. Then I install either single hole or split escutcheons after the cabinet is in place.

Some folks just cut one large opening; I think it looks neater to do it as above. If you're replacing the stops anyway, might as well use the smaller holes.

Changing the cabinet is done so rarely it really isn't worth worrying about it too much.
 
  #3  
Old 05-16-16, 10:29 AM
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I agree with CarbideTipped and will go one step further to say that since cabinets are replaced infrequently, it's a good opportunity to replace the stops anyway. Older ones are probably multi-turn with washers that may or may not work well anymore.

Also, if your drain is coming up through the floor, you'll probably need to reconfigure it with an AAV. "S" traps were common a while ago, but are no longer up to code.
 
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Old 05-16-16, 11:34 AM
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Thanks CarbideTipped and Zorfdt,
What both of you relayed is pretty much what I was thinking given how infrequently cabinets are replaced. Ours are 35 year old... and I don't plan on being the next 'Honey-doo' to replace the new ones.
And the old stops are washer-type stops that actually have failed already. The replacements we found look like the old stops but are actually gate-valves with stainless steel ball.

One question since you mentioned about the traps - ours are the "S" type; What are AAV type and how does that differ in design from old "S" trap?
Many construction code changes I understand the reason(s) for and some are not so clear as to what drove the need to change.
Thanks,
greynold99
 
  #5  
Old 05-17-16, 10:38 AM
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Here's an example of an 'S' trap versus a 'P' trap. 20 or 30 years ago they figured out that S traps tend to suck the trap dry when draining a bowl full of water.
[ATTACH=CONFIG]66241[/ATTACH]

An AAV handles the venting so you don't have to run a new pipe up through the roof. Atmospheric (roof) vents are the best solution, but if your locale allows AAVs, they are much simpler.
[ATTACH=CONFIG]66240[/ATTACH]
 
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