1 1/2″ or 1 1/4″ P traps for sink drains
The plumber intalled 1 1/2″ P-traps in the bathroom and laundry room sinks in my new house. All the tailpipes are 1 1/4″. The local stores carry only 1 1/4″ traps. I’ve lived in houses with 1 1/4″ traps all my life and not had a clog. The new sinks look like they just might be draining a smidgen faster than if they were 1 1/4″. The kitchen double sink and dishwasher drain which I’m installing myself both go into a single trap. It’s this trap that I’m concerned about here. Seems like it might be better to go smaller (1 1/4″) on these and have a clog occurr there, which is easily accessed, as opposed to somewhere further down the drain. I also think that the constant flushing of hot water from the dishwasher helps keep the drains open.
Any comments on how much difference I’m likely to see if I go to the extra trouble to find and install 1 1/2″ traps?
Thankyou in advance – Brian.
Replies
Plumbing codes require 1 1/2" traps for kitchen sinks and allow 1 1/4" for bathroom lavs. Your plumber should know what he's doing - why try to second guess him. Unless you're already having some problem, leave things alone.
The only thing I'd do differently is to have separate traps on each compartment of the kitchen sink instead of only one trap for both compartments.
Edited 8/26/2003 12:43:06 AM ET by allaround
he only thing I'd do differently is to have separate traps on each compartment of the kitchen sink instead of only one trap for both compartments.
why?
really clutters up under the sink
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I put one trap on a double sink, thinking I was being slick saving all that room. One side has a disposer (above the trap obviously). When running the disposer, the path of least resistance is back up the other tailpipe and then this creates this lovely fountain in the other sink.
So if you have a disposer, put two traps in.
I do all of my sink assemblies with Schedule 40 PVC. All glued, except for the connection to the wall outlet, and the whatever connection is required for the drain extension. On those, I use a Ferncos. The traps I use have a plug in the bottom.
With the Ferncos, all a fella has to do is loosen them up, and the whole assembly comes off, in case a snaking is necessary.
Good Luck rg
I'm not at all second guessing my plumber. My builder's plumber has a 1/2 hour drive to my new house and I was merely doing a few things myself. As it turns out I'm putting 1 1/2" ABS pipe in the two ensuite sinks and the kitchen, with plugs at the bottom of the traps (which the traps in the sinks my plumber installed don't have.) My plumber is likely being pro-active in eliminating call-backs by installing 1 1/2" everywhere instead of using 1 1/4" in some places.
I'm going into one trap in the kitchen with two 45's from the second sink. My logic is that the one trap will be continuously kept clear by the regular pressure flushing by the hot dishwasher water.
I also have a soap dispenser installed, which in my experience can be a messy pain when it comes time to fill them (easy to overfill, and fill them often). My solution is to make a short extension to fit on the end of the pump tube, and to place the whole jug of soap on a bracket under the sink. Hence I would like the maximum space that a single trap will allow me.
And now my wife will not be calling me as often to come and fill the soap dispenser!
Thanks for the input - Brian.