Shower waste slow to drain at first

[Timmaa]

This has been happening ever since we had the shower installed as part of a loft conversion but it's gotten worse over the past few weeks to the point that the shower tray has overflowed.

When you first turn the shower on it's as if the drainage flow needs to gain momentum. The tray steadily fills up with water and then flows rapidly down the plughole and the shower tray empties.

I wasn't overly bothered about it before but if the tray is going to overflow before the water begins to drain out then that is obviously not acceptable.

I don't think it's a blockage because all the pipework was brand new. What could it be? An airlock? What can I do about it?

Cheers

[jcgrumbles]

Get your plumber back in mate,you need to know which way the waste water is going,has he plumbed in to existing pipework?Does your bath or sink or other shower gurgle at all?Try to follow the pipework if you have any access at all.Look at the pipes outside,is there enough fall on them?You could try a caustic soda solution down them but it sounds like water backing up somewhere and i wouldnt use that stuff unless you had to

[smoggy]

if its filling up and then quickly draining away its probably not a blockage.
more likely that somewhere on the pipe fall it's not much lower than the shower tray so it needs to build up in the tray before its higher, once higher it starts to flow and the vaccuum/siphon effect empties it quickly and then the sequence starts again

do as jcgrumbles has suggested

[Grizz]

like the guys say you need to get guy back to fix it if prob is there from the start, but it could be getting worse cause the trap is filled with hair, you didnt say if you tried cleaning it.

[Timmaa]

Thanks for the replies guys.

I'm going to try cleaning it before calling the plumber back. It's only just become a big problem in so far as overflowing from the shower tray before it drains out. Once it starts to flow quickly it keeps on going and everything is fine. It's also been over a year now since we had the work done. I can't imagine him wanting to do it for nothing and the first question he'll ask is if we've cleaned it.

I've had a look at the pipework outside the house and I think it's probably something to do with the fall. The drainage pipe is quite a level gradient to the soil-pipe but that's because it's at the top of the soil-pipe. The shower is up in the loft.

Perhaps it's a combination of dirt build-up and the shallow fall. We'll see how it goes after a blast with some cleaner. Can anyone recommend what to buy?

Cheers

[Grizz]

before you buy cleaner, pull the insert out of the shower drain and clean it, if its been a year thats prolly your guy

[jcgrumbles]

Caustic soda will eat all the hair,soap and fat for you,how exactly is the waste pipe connected to your soil pipe?I know i can get enough fanny hair out of my shower trap to stuff a mattress...

[jcl]

Get a plunger from the diy/harware shop and this should fix it
it is probably soap that is clogging the drain.

regards
jcl

[mrgasman]

Caustic soda will eat all the hair,soap and fat for you,how exactly is the waste pipe connected to your soil pipe?I know i can get enough fanny hair out of my shower trap to stuff a mattress...

And the bloke with the dodgy shower waste thinks he's got problems :)

If your backing up as so then it's certainly a problem with the fall....At some point your pipework is climbing a hill then tipping over and getting siphoned out by science ;)..... Now im no expert but ill bet if you put a vertical drop on that pipe outside then a 90 into the soil it would shift a fair bit quicker.

Best resolve of course is to remove the uphill section of pipe the pillock that fitted it left !! Chances are though that that's in the run off the shower waste to outside.

[trent1579]

hi,
1 could be a blockage in pipe or trap
2 could be the fall of pipe needs increasing
3 also check the base of the shower with spirit level it must be level to aid drainage
4 check the discharge end of the waste pipe is blocked (hopper or gully only)

[DW190]

You also have the problem of freezing if there is the slightest length of pipe without fall outside. Even cast iron 4" soils have been freezing if any taps have been dripping constantly.

[Timmaa]

Thanks for all your advice fellas. Much appreciated!