Adding a new pipe to an existing soakaway

[RogGriffin]

Hi,
I am in the process of building a new detached apex garage and have a question regarding the rain water drainage from the roof. We have an existing soakaway which is used for some of the guttering of the house. Is there any problem with directing the guttering from the new garage into the existing soakaway by adding an extra feed pipe into the soakaway?
Thanks

[Tony McC]

As long as the soakaway can cope with the additional input, no problem at all.

[RogGriffin]

OK,
I have now located a 110mm Orange plastic pipe that goes into the soakaway.
Can I connect downpipe directly into the 110mm pipe, via a boss or some other method, if so could you tell me how ?
Thanks

[Mark B]

since its not foul waste water, there is probably no need for a trap, so the rain water pipe can be directly conected to the 110mm dia pipe using either a hopper, or there is some other reduction piece avaliable that would allow a rain water pipe to connect to the 110mm dia pipe.

[RogGriffin]

OK. But is there any reason why I can't take the 68mm downpipe underground for a few metres (approx 4m) to then join onto the 110mm underground pipe using one of the reduction pieces ?

This would save having to lay a small run of 110mm underground pipe.
Thanks

[Tony McC]

68mm pipe isn't strong enough to be buried. It will deform. It's up to you to decide whether it's worth the risk.

[RogGriffin]

Thanks. I assume that there are no building regs about this then ?

[Tony McC]

Building Regs require drainage to be 100mm diameter as a minimum.