The toilet is 3 or 4 inch and the shower is 1 1/2 or 2 inch. You could reduce the toilet to 2 inch, but it would never flush correctly or be of much use. The current toilet drain has no trap in that section because one isn't needed. The toilet itself is the trap. If you are using existing waste lines, they should already be connected to the vent stack. If you are adding lines, connecting to the existing stack is fine as long as it is above the last drain.
You need at least a 3 in. pipe -- shower is 2 in. pipe
If you reduce the soil connection to 2" and install a trap
The drains for the shower, toilet and sink all connect to a common line. Assuming the toilet is not backing up, the problem indicates that there may be a partial blockage, enough so that some of the toilet flow is backing up through the shower drain line. You need plumbing repair. The shower leak you mention should only be in the shower, or else you have a broken drain line as well.
Are the shower and toilet blocked in your bathroom?
No, flushing the toilet does not affect the temperature of the shower water.
A down line clog would cause this. The shower drain is lower than any other drain in the bathroom so it is the first to tell you of a clog in the line. Time to Roto Rooter! Y-THINK-Y The toilet and shower must have the same drain. There is a blockage somewhere after the toilet and shower drains meet. The backup takes the easiest route back which must be the shower drain. Try snaking out both drains. Start with the toilet. To do the best job, remove the toilet and start from floor level.
Toilet bubbles appear when you shower because the water pressure from the shower can create air bubbles in the plumbing system, causing air to be pushed through the pipes and into the toilet bowl.
Flushing the toilet can affect the water temperature in the shower because both the toilet and the shower are connected to the same water supply system. When the toilet is flushed, it temporarily reduces the amount of water available for the shower, causing a drop in water pressure and potentially affecting the temperature of the water coming out of the shower.
This indicates that it has a toilet, sink and a shower but no bathtub. A 1.50 indicates that it has a toilet, sink but no shower or bathtub.
A bathroom would have a toilet-sink-tub and or shower. A half bath has a toilet maybe a sink but no tub or shower.
I can be but the toilet needs to have 24" in front of it to be legal. Plus you cannot tie your shower drain in the the horizontal branch of the toilet.
Because the Shower Hummed