Connecting drain to closed boss on bottle gully

[Daveo119]

Hi,

I’d like to use a bottle gully which currently takes the output from a roof downspout to take the output from a perforated pipe drain I plan to run behind a new retaining wall in the garden. The bottle gully in question has closed boss inlets (eg marley ug50). Presumably you need to solvent weld something onto the boss to make use of the connection? Can someone enlighten me as to what is normally used to connect to 110mm?

PS all new drains are being installed so I have the option of connecting the perforated pipe to the pipe run from the gully to the IC with a branch. Besides simplifying the pipework, I liked the idea of using the gully trap to collect any soil that may get past the pipe sock. Is this a stupid idea?

thanks

 

[John D v2.0]

If it's just a plugged ring seal entry you should be able to just chamfer the new pipe and lubricate it, then insert it.
Regarding having a silt trap that can be a good idea because surface water drains can easily get plugged up with silt. Thames water had a lot of fun trying to get ours cleaned out, including the huge one in the street!