My shower is on the first floor, slab construction, and does not have a trap. What can I do to prevent the smell from the cesspool from coming back into the bathroom?
Thank you,
Leslie

Find somewhere along the drain to dig up the concrete and install one!
Or raise the shower pan and install one underneath/nearby and have a step up to the shower.

HI all:

A PTRAP and vent is required on all fixtures as you already know, Question123456

Another alternative until you break up the floor and fix this is called the GRATE SEAL... made to fit any floor drain or shower strainer according to the manufacturer's video. Check it out at:

Google Image Result for http://www.youtube.com/watch?v=ucEG-yucgS8

Click on the video presentation.. real quick video.

You can also check it out at this website:

http://www.google.com/imgres?imgurl=http://www.grateseal.com.au/assets/GS3Dweb.gif&imgrefurl=http://www.grateseal.com.au/&usg=__z4aCE3sWITq-rdcafghKddrnelg=&h=210&w=210&sz=234&hl=en&start=0&zoom=1&tbnid=ol_fmXw4xCXE2M:&tbnh=139&tbnw=123&prev=/images%3Fq%3Dgrate%2Bseal%26hl%3Den%26sa%3DX%26gbv %3D2%26nfpr%3D1%26biw%3D1142%26bih%3D761%26tbs%3Di sch:1&itbs=1&iact=hc&vpx=333&vpy=127&dur=703&hovh=168&hovw=168&tx=103&ty=98&ei=xzUaTe25BoOBlAfA2MjPCw&oei=xzUaTe25BoOBlAfA2MjPCw&esq=1&page=1&ndsp=24&ved=1t:429,r:1,s:0

Here, the rubber seals the gasses from escaping the pipe but also allows water to flow through by gravity.

Let me know if you have questions...

MARK

How do you know it doesn't have a trap? It could have a trap under the shower and the trap has a crack in it. In either case, not an easy fix since you will need to remove the shower pan.