New Tub - Remodel on Slab - Slow Drain
Please Help. I have just remodeled a basement bathroom (on slab) and moved a shower drain approximately 4' to create a drain for a tub in its place. I checked the level of the drain line to make sure that it had fall to the old shower connection in the slab and it was about a quarter of a bubble. I got the tub set up and it drains, but very slow. When all the water has drained, there is a 'glug, glug, glug' sound. I am at a loss as to what to do. I definitely do not want to cut into the slab again. Could the shower have had another p-trap and the two p-traps are making it drain slowly? Could the main waste water line and the shower drain be too close to the same level? There's only about a 1/2" clearance from the waste shoe on the tub drain to where the p-trap loops back into the new drain line - could this be the trouble? Should I elevate the tub (can't go more than 3" because of a drop ceiling and a 6'2" shower user?
Is there anything that I can do to improve the drain time? I don't have the shower head hooked up yet, so I don't know if showering will be a problem (leaving water backed up in the tub).
Any help would be greatly appreciated!
JR