Hi, I have a 3 story house with my kitchen in middle floor. My kuitchen sink waste pipe goes outside and into a pipe that rest in another vertical pipe to take it away. This is just above my ground floor conservatory. The plastic pipe has now shattered just after the 90 degree bend connector. I have tried to unscrew the 90 bend connector but it seems stuck - i am having to do this hanging out my kitchen window at full stretch ! Any advice - i am unsure if it is actually a screw fit or push fit or evena compression joint - any advice? please