Slow draining bathroom sink

Markp1984

Hi everyone, I've got a little issue with my bathroom hand basin. When I use the water, the first litre or so drains away with no issue, but after that it backs up, draining about half the speed it should. 

I have tried a chemical unblocker a few times with no success, I had the exact same problem about 5 years ago, and needed a plumber, who I recalled pulled up part of the floor to expose the pipes. He wasn't here very long to sort it and so I thought maybe if I'm brave I can try it myself, though I've zero plumbing experience! 

I've pulled up the flooring that he did, and I've labelled the flow of water with red arrows to help get your bearings.
 It flows into an internal stack so there's no realistic way of getting to it from any other direction.

Any advice would be much appreciated, even if the advice is that I do need a professional! Thanks so much,
Mark

Aslan69

You’ve got a partial clog in the horizontal pipe under the floor, chemicals won’t fix it. Since you’ve exposed the area, grab a proper drain snake (5–10 m), remove the trap, and feed it into the pipe until you hit resistance. 

Markp1984

Aslan69 said:

You’ve got a partial clog in the horizontal pipe under the floor, chemicals won’t fix it. Since you’ve exposed the area, grab a proper drain snake (5–10 m), remove the trap, and feed it into the pipe until you hit resistance. 

I've actually got a 5m drain snake.. but I don't know how to undo anything, I've zero experience and not much confidence in my DIY abilities! Thanks

grumpy_codger

You can 'undo' the nut near the red marker line (and/or the other nut nearby). Also, all other connections are 'push-fit' and can be easily 'undone' (but it's worth cleaning them and then adding some washing-up liquid or soap before re-connecting).

531063

If you can access the waste pipe from outside try shoving a garden hose up it to see if that will shift any blockage

grumpy_codger

531063 said:

If you can access the waste pipe from outside try shoving a garden hose up it to see if that will shift any blockage

Markp1984 said:

...
 It flows into an internal stack so there's no realistic way of getting to it from any other direction.

🤔                  

kimwp

If you take the joints apart, note (write on the parts and take pictures maybe) of which part is linked to which and how and which way round it is. You'll find seals inside the joints, keep those (in the right orientation), with the bits they were with, to make reassembly easier. 

It's definitely doable to take pipes apart, clean and reassemble if you do the above.

Eldi_Dos

@Markp1984
Before you disconnect any pipework you could try this.

Get a plunger
Fill the bath up to overflow with cold water, then with sink cold water tap running let water out the bath and give it a few plunges to see if that clears any debris, hair ect in the pipe.The increased pressure and flow is sometimes enough for to see a improvement, without disconnecting pipework.

FreeBear

kimwp said: It's definitely doable to take pipes apart, clean and reassemble if you do the above.

Don't forget to put a bowl underneath to catch any water that spills out. Also have a pile of old towels within easy reach just in case you get a bit more than you bargained for.

Markp1984

Eldi_Dos said:

@Markp1984
Before you disconnect any pipework you could try this.

Get a plunger
Fill the bath up to overflow with cold water, then with sink cold water tap running let water out the bath and give it a few plunges to see if that clears any debris, hair ect in the pipe.The increased pressure and flow is sometimes enough for to see a improvement, without disconnecting pipework.

Thank you, I did try a plunger first off, blizzarely it made it worse! Could be that it would get better with more plunging but I don't want to take the gamble as its still moderately usable.
Last time(5 years back) it did it I had one of the guys with a high pressure hose come in, that cleared it for just half a day. It's a bit of a mystery what's going on down there. Thanks for the reply. 

Alfrescodave

Youtube is always a great help in these kind of situations.