I recently renovated the bathroom, replacing the existing drain plumbing with new ABS in same configuration, but now the tub won’t drain. It was slow before the renovation, but water is now actually back-flowing into the tub from the sink.
Description – bathtub drain is 1½ ”, extends from bottom of tub down to P-trap, then across a 8” horizontal length and Tee’s with a vertical 1¼” length (upwards is the vent which connects to the Stack in the attic and vents outside through the roof – all of which are clear of blockage). The vertical pipe continues down about 1’, then connects to a horizontal run of about 8’ (drop is about 4” along this length), meets with the sink drain, and continues another 4’ to the Stack. The sink drain is not vented.
Given the back-flow of greywater from the sink into the bathtub, I know the 8’ length of pipe fills with water, then drains slowly. Can this be due to air-lock? (All plumbing is now enclosed, but I can go through the walls behind the sink and tub from other rooms to either add a length between overflow and vent pipe, or add a valve on top of sink drain to allow in air, if required). Any advice would very much be appreciated.
Two small kids without a functional bath!! Help!
Description – bathtub drain is 1½ ”, extends from bottom of tub down to P-trap, then across a 8” horizontal length and Tee’s with a vertical 1¼” length (upwards is the vent which connects to the Stack in the attic and vents outside through the roof – all of which are clear of blockage). The vertical pipe continues down about 1’, then connects to a horizontal run of about 8’ (drop is about 4” along this length), meets with the sink drain, and continues another 4’ to the Stack. The sink drain is not vented.
Given the back-flow of greywater from the sink into the bathtub, I know the 8’ length of pipe fills with water, then drains slowly. Can this be due to air-lock? (All plumbing is now enclosed, but I can go through the walls behind the sink and tub from other rooms to either add a length between overflow and vent pipe, or add a valve on top of sink drain to allow in air, if required). Any advice would very much be appreciated.
Two small kids without a functional bath!! Help!
