Slow running sink

Maxson

We have a little bathroom in our loft conversion. The sink in there has a tendency to run slowly towards blocking. I've added a pipe clip to hold the pipe on the wall straight, I've cleaned out the sink trap and adjusted that as best I can. The only thing that has worked is using 'Buster' plughole un-blocker regularly and maybe that's the only thing I can do as the blockage must be happening in the pipework behind the wall. This is what it looks like from the bathroom side:



I've made access into the remaining loft possible and added insulation and boards so I can move around in there safely. While I was there I had a look at the other side of the wall where the white waste pipe from the little bathroom sink goes through. I can't actually fit in there or reach the pipes with my hand. It looks like the slope might not be adequate on part of the white pipe from the sink. I took a photo while I was there:




 Any advice?

Browntoa

The 2nd picture, it's hard to work out if that is level or slopes slightly upwards

Maxson

Browntoa said:

The 2nd picture, it's hard to work out if that is level or slopes slightly upwards

I'm not sure. I couldn't get a spirit level on to the pipe. My guess is that it's either almost level or slightly sloping the wrong way and that's why stuff is accumulating in that corner. The toilet waste it's connected into runs fine by the way.

Jeepers_Creepers

At least you know what the problem is!

But - how to fix it...

I think the simplest solution - which would hopefully not actually require you to squeeze into that loft gap - is to cut a vertical slot above where the pipe goes through the wall, around 2-3" high. Cut right through, and lift the pipe at that point so's you introduce a slope into the section beyond the wall. It looks as tho' you have plenty of fall to play with on the bathroom side - it looks to be more than a tile height's fall along that wall? 6+" You can lose some of that.

How to cut into the tile? Either by using a cutting tool such as a Dremel with a diamond grinder tip, or even a hand tile cutter if there is one with a padsaw-type handle, or - easiest DIYer - remove the two tiles involved and cut and replace them afterwards. But that would risk spoiling that beautiful tiling...

Elmer_BeFuddled

The white to grey is deffo going up in my eyes. needs 10mm(?) taken out off the short stumpy "down" pipe to rectify.

531063

Has the sink always run slow ?, if so it could be lack of fall if not more than likely a blockage.

Jeepers_Creepers

Elmer_BeFuddled said:

The white to grey is deffo going up in my eyes. needs 10mm(?) taken out off the short stumpy "down" pipe to rectify.

Well, ok, that could also work, and, well, ok, it's a much easier plan... :-(

It would be nice if 10mm would do it.

Jeepers_Creepers

Ooh! Ooh! Ooh! The 4" soil pipe fitting that white waste is going into - looks like a boss connector - is there anything else going in there? It doesn't look like it - I think the toilet's waste goes in to the next fitting upwards? - then in theory that boss connector section can be rotated anticlockwise an inch or so so's the basin waste's boss inlet is further down the side. But not turn it as far as half-way. 

Between that and removing that half-inch from the pipe going it, you may crack the problem. 

fenwick458

Elmer_BeFuddled said:

The white to grey is deffo going up in my eyes. needs 10mm(?) taken out off the short stumpy "down" pipe to rectify.

I think this would be my first job. cut as much off the vertical pipe as possible to get it right down to the elbow.
if thats not enough you could try fitting one of these into the soil pipe, and then get a straight coupler and a bit more waste pipe to extend it so it's long enough to reach it, it will give you about 25mm more fall

Maxson

Jeepers_Creepers said:

At least you know what the problem is!

But - how to fix it...

I think the simplest solution - which would hopefully not actually require you to squeeze into that loft gap - is to cut a vertical slot above where the pipe goes through the wall, around 2-3" high. Cut right through, and lift the pipe at that point so's you introduce a slope into the section beyond the wall. It looks as tho' you have plenty of fall to play with on the bathroom side - it looks to be more than a tile height's fall along that wall? 6+" You can lose some of that.

How to cut into the tile? Either by using a cutting tool such as a Dremel with a diamond grinder tip, or even a hand tile cutter if there is one with a padsaw-type handle, or - easiest DIYer - remove the two tiles involved and cut and replace them afterwards. But that would risk spoiling that beautiful tiling...

I did consider cutting out above the pipe and raising it in the wall. Assuming there is no noggin or anything in the way.

Lol at beautiful tiling.

Maxson

Elmer_BeFuddled said:

The white to grey is deffo going up in my eyes. needs 10mm(?) taken out off the short stumpy "down" pipe to rectify.

Not knowing much plumbing should that short white pipe just pull out of the grey waste, cut off 10mm and push it back in? Nothing to unscrew or any sealant? That is if I can reach that part to pull it out and cut it.