Had our bathroom renovated recently. The bathtub drain does not have a P-trap - it joins into the toilet drain. Would the absence of a bathtub P-trap affect the flushing of the toilet ?

No, but if there is an open drain pipe to tub and there is no trap you will get an odor. But that will not affect the toilet flushing.

Call the reno company back, the way it is connected is a health hazard.

I agree with the experts,
Before we can help you have to tell us what the problem is with the flush.
But you have a more urgent issue here. The lack of a trap on the rub leaves your house with a direct connection to the city sewer allowing sewer gas to enter your home, Sewer gas is harmful to your families health and should be addressed ASOP, I would also make az formal complaint to The Building Department concerning a code violation and shoddy workmanship. Good luck and let us know the outcome, Tom

How do you know there is no trap, is this exposed for inspection?

Thanks very much for your replies.
I don't know for sure that there isn't a trap, I'm suspicious due to shoddy work elsewhere in the same reno. I guess I'm hoping to get a better indication that this might be the cause of the poor flushing before I start ripping my living room ceiling out.
To be more specific about the flushing problem - it seems like the water flowing from the tank into the bowl is fine but the water flowing out of the bowl doesn't gain enough momentum to fully empty the bowl. I'm almost always left with solid waste and toilet paper still in the bowl that needs to be plunged out with a second flush.
I've tried adjusting the water level in the tank without any success.

We need a few more details. Is the tank level 1/2" below the top of the white overflow tube? Does the water raise up to the rim and then slowly drain away leaving solids behind? Let me know. Back to you, Tom

This sounds more like an obstruction in thje drain rather than no trap. Please answer Tom's question.

Thanks again for your replies.
The tank level is right up to the top of the overflow tube.
In the second question, I assume you're asking about the bowl rim -
No it doesn't rise up to the rim, it starts to drain normally but then slows down and
The water level doesn't drop down anywhere the bottom of the bowl.


Thanks again for your replies.
The tank level is right up to the top of the overflow tube.
In the second question, I assume you're asking about the bowl rim -
No it doesn't rise up to the rim, it starts to drain normally but then slows down and
The water level doesn't drop down anywhere the bottom of the bowl.
Thanks again