Broken P-trap in the slab
	
	
		My house is 22 years old.  The shower in the master bedroom began to smell like sewage a year ago.  At first it was very faint, now it is quite strong.  A plumber was called and he said the P-trap, which was in the slab, leaked and therefore the seal no longer existed to block the sewage gas.  This plumber said there was a drop-in P-trap for this application but when he called his supplier they did not have that device in stock. 
Here are my questions:
1) Is his diagnosis correct?
2) Is there such a thing as a drop-in P-trap?  I talked to Home Depot, Ace, Lowe's and no one knew of such a thing.
3) Busting up the slab to get to the P-trap is out of question.  In the long run, will this leak cause damage to the house's foundation?
4) Is it possible to build a secondary floor above the existing shower floor in order to accommodate a new P-trap?  It is going to take some modifications to the shower stall, but this approach seems to be the most feasible. It certainly is better than busting up the existing slab.  
Thanks in advance for your suggestion.
Howard
	 
	
	
	
		Broken P-trap in the slab
	
	
		I am having problem with a P-trap in my shower stall, which is built into the house slab.  I looking for remedy and sureseal is one option.  However, I visited sureseal website and could not find an explanation of how it works.  Is this like a plug you manually open when you use the shower and then manually close it after you are done with shower?
The sureseal wesite does not explain the mechanism of this device. 
Do you know how well it works and the pluses and minuses of this device?
Thanks.