Dripping leak under tiled floor from joint on a basin supply pipe

davidod1

I am wondering if it is possible to stop a very slow leak with Fernox or equivalent on an internal supply pipe.

The background is this: During a bathroom refurb it was necessary to cut and modify the hot water pipe to a wash hand basin. The suspended timber floor was tiled over, but it became obvious that there was leak when hot water always arrived in the tap within a second or so of turning it on. Previously it would have taken perhaps ten seconds or more. The plumber removed a tile and saw the leak, but it was not an easy stretch to get it tight. He told me that it was perfect and replaced the tile and it appeared to have been sorted.

A couple of months after that 'repair' there seemed to be a bit of a manky smell in the bathroom and that has persisted since, and indeed it can be quite unpleasant. It smells like rotten water. I am quite convinced that there is a slow leak from the joint that he tried to fix, but I don't want to start lifting tiles to confirm this.

Does anyone know how I could use Fernox or an equivalent in this water system. I see on the Fernox website that they say it can be used on a domestic fresh water system, but they don't give guidelines on how to do it. I did email them asking this, but they never replied.

Any advise would be very much appreciated.

GreeBo

so assuming that this is a ground floor bathroom you dont really have any option other than to pull up a tile...

But, if the leak is such that its keeping your hot water effectively running, then I'd be amazed if you didnt see signs of it somewhere else, it certainly wouldnt be a "very slow leak"!

Is your cold water tank constantly filling in the attic?

Do you have a bath etc that you could remove a panel from to see under the floor?

Alternately, removing the basin/pedestal might give you enough space to see under the floor and take a photo with a phone camera. If the leak is as bad as you suspect it should be obvious.

Were you there when he lifted the tile? Did he also remove floorboards or how was the pipe/leak exposed?

davidod1

To answer your questions GreeBo. - Thanks for the help.

It is a ground floor. The initial leak was bad, but I suspect that the current leak is just a very slow and occasional drip. It has been been nearly a year since the job was done. It was quite a few months before I began to smell what believe can only be from a slow water leak. He did have to lift a floorboard to expose the leak, but it was still a good arms length away. The attic tank does not have any constant drip in to it. I think the leak would be too slow to see that. The bath is located in a different area and wouldn't help in access.

GreeBo

Ah, i missed that the initial leak was the one that led to the "instant" hot water.

Even if the bath isnt close, it might be enough to allow you to have a look?

Do you have any spare tiles?

davidod1

https://www.boards.ie/discussion/comment/118425159#Comment_118425159

Last tile used when the main leak was looked and supposedly sorted. The bath is well away from where this issue may be.

What do you think about trying a leak sealer, and if so how do you get it in to the system, and if it's a runner, does the water need to be hot like with Radweld in the old days?

GreeBo

I've never seen an internal (within the pipes) sealer for domestic water, only for central heating...the fernox sealer that I have seen is applied to the outside of the pipe/joint as a paste.

How close is the leak to the sink ? Assuming the sink is on a cabinet or pedestal can you move that to open up more flooring?

A photo/diagram would help

davidod1

"I've never seen an internal (within the pipes) sealer for domestic water, only for central heating...the fernox sealer that I have seen is applied to the outside of the pipe/joint as a paste." It may be that the reference that I saw was for sealing outside the joint. I assumed it was a liquid seal.

How close is the leak to the sink ? Assuming the sink is on a cabinet or pedestal can you move that to open up more flooring? The pedestal was put in location after the floor was tiled, only a hole for the pipes was left.

Thanks for contributing, much appreciated. It looks like I will have to see what I can do about getting a few replacement tiles and then just 'go for it'.

Dave

P.S. Not getting notified about posts, the option is ticked in my profile.