22:22, Wed 10 Jan
Whenever someone in our house has a shower, I keep hearing this odd occasional noise in the outside pipe leading from the bathroom to the soil stack. It is like a kind of creaking. Not sure if I am imagining it...is it just the pipe expanding in the cold weather as the hot water flows through it. Just wondered if anyone had ever come across this before?
22:37, Wed 10 Jan
What’s your pipe made from?

Not that I have any idea as to the answer, I just have old pipes that make noise and newer plastic ones that don’t in my house.
22:38, Wed 10 Jan
Haircut1000
Whenever someone in our house has a shower, I keep hearing this odd occasional noise in the outside pipe leading from the bathroom to the soil stack. It is like a kind of creaking. Not sure if I am imagining it...is it just the pipe expanding in the cold weather as the hot water flows through it. Just wondered if anyone had ever come across this before?

Yep... expansion and contraction of plastic pipes due to change in temperature.

Even your gutters do it in summer!
23/01/20 Mad: I'll stop moaning now.
22:53, Wed 10 Jan
B_C_F_C
Haircut1000
Whenever someone in our house has a shower, I keep hearing this odd occasional noise in the outside pipe leading from the bathroom to the soil stack. It is like a kind of creaking. Not sure if I am imagining it...is it just the pipe expanding in the cold weather as the hot water flows through it. Just wondered if anyone had ever come across this before?

Yep... expansion and contraction of plastic pipes due to change in temperature.

Even your gutters do it in summer!

Ah good to know. That's reassuring.