Bigger and longer P-trap

[Mudball]

I was wondering if I could install a larger and deeper/longer P-trap under a shower/tub unit for reasons of after a few years this unit will not be used as much and I would be concerned with it drying out. If this is possible then are there more draining problems with this kind of set up ?
Should I use standard P-trap now and then deal with problem when and if it happens ?
Im also asking because this unit will be sitting on concrete pad and be hard to replace.

[FloridaOrange]

Out of my code book (Florida)

2007 FPC 1002.4 Trap Seals. Each fixture trap shall have a liquid seal of not less than 2 inches (51 mm) and not more than 4 inches (102 mm)

You could run a trap primer for a permenant solution.

[Cass]

Personaly I would just run all the fistures for 10 Min. a month and forget an oversized trap, and be done with it...they do need to be used reguardless...

[Mudball]

Sounds great. Thanks for the help.
Another question is would you install the P-trap in the concrete and stub up or would you rather raise the shower/tub unit off the floor for enough room under to replace p-trap ?

[FloridaOrange]

I would install in concrete, there are trap "boxes" to form an access area for the tubs if you are worried about it.
Raising a tub enough to create access above the slab could lead to other problems.

[Cass]

I would box out for the trap and not have it encased in concrete then install the shower base according to the instructions that come with it...

[Mudball]

I think I like the "poured in concrete" idea.
Thanks

[nhmaster]

We always box out tub traps. If you ever have problems with the waste/overflow, working on it with the trap encased in concrete sucks. If you are worried about the trap drying out, fill it with vegetable oil.

[Mudball]

Thanks. Thats not a bad idea either since you and another have suggested it and with further consideration of more research. Since there are only two of these to be done I will most certainly check into and highly consider the box method.
Thanks again.

[hj]

All a larger trap would do would be to extend the time before it dries out by a couple of weeks. It would not be a permanent solution. You cannot raise the shower high enough to allow replacement of the "P" trap, (and I do not know why that would ever be necessary), unless you put it 2' above the floor so you could crawl under it.

[nhmaster]

A Rubber Maid or similar storage box, placed upside down over the stub makes a good box because you can leave it above the cement and trim it flush later.

[Scuba_Dave]

We have an upstairs shower that isn't used
I either dump some water down the drain (from dehumidifier) every now & then or turn it on for a minute or two

[Terry]

The reason plumbers box out and install the p-trap later is two reasons.

1) After the concrete pour, the trap wouldn't be where you plumbed it,

2) The framers pulled from the other side of the foundation, which was sized wrong to begin with and now the measurement is off

3) The drain on the shower is lower then the floor and needs a recess.

[jadnashua]

Having a large step out of a shower is a big safety hazard. Stepping over the curb just makes it worse. I was in an inexpensive ground floor hotel in London once where they built up the base of the shower to put in the required trap, and almost killed myself getting out!

[Mudball]

Very good reasons. Now I better understand why its done that way.
Thanks