Soil stack leaking

[robinbanks]

Though do note that you're supposed to glue it to the stack pipe so https://www.screwfix.com/p/floplast-sc250-solvent-cement-250ml/14295 too.. Apply glue to pipe in the right place then push collar down and rotate it around the pipe to smear out the glue in the pipe:collar contact area

Note that SF sell black collars too, which may look less gash than a grey one