Water spilling out of outside hopper when bath is emptied

[wowfudge]

I wonder if anyone can help? When our bath is emptied, the hopper the down pipe empties into overflows and the water spills onto the pitched roof of the garage below, bounces off that and ends up on the concrete below. The bathroom was a DIY job and we think the outside associated external pipework (plastic), with the exception of the soil pipe which appears to be original to the house (cast iron, 1930 house), is too.

So how do we stop this happening? I have found that slowing down the rate the bath empties prevents this, but I don't know if you can have a bath that empties 'too quickly'? Perhaps the waste water pipe from the bath is too big?? The other potential issues which I think could be the problem or part of it are that the hopper is either too small or that the pipe which empties into the hopper is set too far down so with the volume of water coming from the emptying bath, it hits the base of the hopper and splashes up. We are going to re-do the bathroom soon and I would like to get this problem fixed at the same time, but I think knowing what needs doing would be useful.

Any assistance gratefully received!

poke around in the hopper, and the shoe at the bottom of its downpipe. It might be clocked with leaves. A straightened wire coathanger will hook them out and you can throw on the garden or in the bin. Don't try to push a blockage into the drains.

Do what pigletjohn says and if that doesn't work, you may need rods. I tried to clear mine with coathangers/bamboo canes but it was full of revolting stinky gunk so my plumber friend sorted it out for me

Yes, it's most likely a blockage of leaves or moss. Not a major issue at all. Our landlord sends someone (a plumber or some other handyman) out every winter when our bathroom drain inevitably backsup. We end up with a lovely waterfall cascade over our kitchen window when it happens...

I hadn't thought of that to be honest, but it's the same hopper that both the bathroom sink and the shower empty into without any problems....

Unfortunately it's not very accessible either as the bathroom is at second floor level and the garage roof immediately below it is pitched and some sort of corrugated plastic cladding.

What is the shoe please PigletJohn?

downpipe shoe

Thanks for that PigletJohn - I'll have a look. I think Aldi have had some rods in recently - they might have some left.