Locations Of Trap Adapters

[Dlarrivee]

On the internet and in books I see a lot of trap adapters installed directly in a sanitary tee.

Like this:

But most of the places I've lived have the trap adapter at the top of the trap itself.

Like this:

Now I can see installing it directly into the T for a pedestal sink, but is it a Canadian / US difference or preference or is there just situations where one installation is better than the other?

 

[Cass]

A trap adaptor can be used any where a connection is made that at some time in the future you might want to take it apart..it can not go in a wall that is being covered up unless there is going to be an access cover. Over traps are the most common place they are seen...

 

[Sponsor]

 

[Jimbo]

In many places, you have a choice of running all tubular from the tee. In MA, you cannot have any joints like that before the trap.

 

[Dlarrivee]

I realize you can put it anywhere other than inside a wall, I'm just wondering if it's wiser to use a glue in P trap like in my second picture, or put the adapter right into the T and run a tubular P trap and trap arm...

There's obviously 2 ways of going about it (maybe more?), but I'm just wondering if anyone has a good reason for choosing one over the other?

For example, a lav, inside a vanity?

 

[Dlarrivee]

In many places, you have a choice of running all tubular from the tee. In MA, you cannot have any joints like that before the trap.

Is it possible this is a Canadian code as well?

 

[Dcelite]

I like using the ABS trap like in the second picture. They have a larger inside diameter.

 

[hj]

It is a personal preference by the installing plumber. I, personally, NEVER use the schedule 40 trap in the second picture, and usually cut them out, and replace them, when I work on a sink that has one.

 

[Dlarrivee]

It is a personal preference by the installing plumber. I, personally, NEVER use the schedule 40 trap in the second picture, and usually cut them out, and replace them, when I work on a sink that has one.

Any particular reason for this or just an old habit?

 

[hj]

Good question, but since that large lock nut on the sch. 40 traps has a tendency to "freeze", warp, or crack they often have a limited number of times they can be used for access before they have to be changed anyway. The slip joint traps and piping are just easier to line up without possibly having to make "trim cuts" to get them to fit.

 

[Terry]

I cut out the schedule 40 when I see it too.

 

[Dlarrivee]

Thanks a lot guys, I'm always interested in these details, it makes sense to me for serviceability to not go with sch. 40 traps...