Bathroom Leak - what to do?

Heedtheadvice

Assuming I am right,  here are some explicit step by step instructions to fix your leak. Similar to above) not difficult but a bit fiddly...

[This does not cover any inspection of the flooring/woodwork underneath which should certainly be inspected and dried. The latter may take some time! Not worth doing that till the leak is fixed though the toilet may have to be taken out afterwards for access.]

That looks like:

Your leak source. 100ml in an hour is a lot, enough to give you that problem over time;

it is a 15mm flexi screwed onto  plastic cistern  connector. If you have it's water supply turned off, flush the toilet to empty most of it out. Remove the cistern top to get access to the interior to dry it thus preventing more unwanted spillage. The flexi itself might have a service valve if so then the screwdriver slot to point across the pipe to cut off the supply locally.( along  the pipe is on)

Undo the flexi pipe from the cylinder connector   catch the water inside the flexi. You can get 'crows foot' spanners to work end on to the connector. Inside the end should be a sealing ring. Do not loose it.

The plastic connector can be a sod to get tight/sealed onto the cistern.  It looks like that is where the drip is coming from. The inside the cistern part of it might be the float valve assembly. You need to hold the base of it to prevent rotation when unscrewing/ screwing the plastic nut on the outside.

Completely dry the plastic nuts/ thread/ washers and mating cistern area.  clean with some meths and allow to dry.

Reassemble with some silicone sealant on the parts/washers that mate with both sides of the cistern. It does not need much but needs to be a continuous 'ring'. Again while holding the inside plastic bits that mate at the cistern screw on the external washer nut as hand tight as you can get and then a bit more using pliers or similar. Do not overtighten or the plastic threads might be stripped.

 refit the flexi and again prevent rotation of the plastic bits. Leave for the silicone to cure as per manufacurer's instructions. Refit cistern lid. 

After that time ( maybe next day) turn on the water, make sure the cistern fills  ( and then stops!) Check for leaks. As mentioned above kitchen roll is good to catch and show up any drips.

Over time there may be a slight short tetm dampness due to condensation otherwise there should be No leaks.

If all fine you can then go on  to sorting the damp woodwork/ flooring.

bjorn_toby_wilde

It’s leaking past the fill valve washer by the look of it. That’s at the base of the fill valve inside the cistern. Have a look at the fill valve inside the cistern. It may be twisted or pushed to one side.  They’re fitted into a tight space so sometimes when the nut is tightened up they will move and wedge against the side of the cistern. That can cause a leak at the bottom. Turn off the water AND flush to empty the cistern as far as possible before you work on it. There will still be about a pint of water left inside so get something ready to catch it when you undo it.

Tightening the nut may not do anything for the leak and they’re plastic, so easy to overtighten and split.

You may have to replace the fill valve washer or maybe just clean it up and refit it. There’s a decent video here https://m.youtube.com/watch?v=HmF22-6c7bA

WIAWSNB

Maffy52 said:

plumb1_2 said:

WIAWSNB said:

This might seem daunting, but is actually ok - just rip it open, 

I would use a Stanley type blade and cut the sealant off, then gently pull the board off.

thanks. Have just taken off the board. There is a drip from the inlet into the cistern, must be the source of the leak. It seems like nothing but the container I put underneath had 100 ml of water in about an hour, so must be this, see photo! Maybe this drip has been going on for a while, but I just never noticed before!

How would I go about 'tightening this connection up, I can't see how to get a spanner or wrench in the space (do I somehow lift up the cistern?)

Well done for finding that.
Does the other end of that Flexi hose have an isolating valve? Ie, a chrome fitting with a screwdriver slot in its side. If so, giving that a quarter-turn, so the slot is at right angles to the pipe direction should stop the flow to the cistern.
Then flush the cistern - it shouldn't refill. There will still be some water left inside it, so it'll continue to drip for a while. Just keep catching every drip.
Do you have another toilet you can use? If not, then you'll have to keep using this one - just catch every drip.
If there's any doubt about the floor being permanently damaged and unrescuable, then insurance may well be your best call. Look at your policy to see if, say, 'emergency cover' is included, which means they might come out and sort it, as well as investigate further damage. Keep an eye on excess charges, tho'.
Tbh, I wouldn't recommend a DIY fix to the cistern unless you know what you are doing. It might be sorted with just a part-turn of that white nut, but it might not. Also, you should be holding the actual inlet valve inside the cistern steady whilst you try tightening that nut.
Perhaps a recommended plumber job...
Can you lift the lid of the cistern? If so, you can scoop out any remaining water - that will make the drips stop.
Finally, as you are waiting to sort this, at least keep the bathroom window as open as possible, and the door too - let it ventilate and dry.

WIAWSNB

Soz, I've just had another look at your first pic. 
The cistern is fully accessible, so a plumber - or DIYer who knows what they are doing - should really be able to sort the cause easily. This should be within a one-hour call-out charge.
Meanwhile capture every fresh drip - important. 
The plywood floor looks largely unaffected, with no signs or warping or swelling. Once fully dry it should be completely fine. A 'flooring' person should be able to determine this in an instant. The actual tiles look to be a fully waterproof type, so should also be exactly as they were originally - tho' lay them out on a flat surface so they don't warp. They are almost certainly reusable, and the floor should then be as it was before. Again an hour or so's work. 
Many plumbers provide a full bathroom-fitting service, so have both these skills under one person's, or company's, belt. Double-easy.
The amount of water that went through to the ceiling below is minimal, and this water will dry out in the floor void over the next few weeks. 
I'd personally have no ongoing concerns.
So, what I'd suggest doing is to phone two or three ideally recommended plumbers, and tell them, "There's been a drip from the cistern inlet valve which has left a light stain on the ceiling below, and lifted some of the glue-down(?) vinyl tiles on the bathroom floor. Could you sort both issues, please? If so, ballpark figure? I'm trying to avoid an insurance claim. Oh, I'm catching the drips now, so it's starting to dry out..."
And you could even send the two photos to them.

Oh, and the ceiling stain will need cleaning as far as possible, then stain-blocking, and finally the ceiling painted. Again, within the remit of a 'bathroom' plumber. Or do you paint yourself?

If the ply floor is warped or peeling, then we are talking a much bigger job, so I suspect an insurance claim may be advisable. 

Boohoo

The best thing in my opinion is to get a plumber in and they should do a better job than you 

As it's near Xmas if it's fixed then that's one thing less to worry about.

If it costs you £600 to fix it's more for piece of mind than anything and if you try doing it do you all the tools needed and the equipment to do the job correctly?

Swipe

Boohoo said:

The best thing in my opinion is to get a plumber in and they should do a better job than you 

As it's near Xmas if it's fixed then that's one thing less to worry about.

If it costs you £600 to fix it's more for piece of mind than anything and if you try doing it do you all the tools needed and the equipment to do the job correctly?

£600 to unscrew a plastic nut and replace a rubber gasket? Absolute madness. If they've gone as far as sourcing the leak themselves, I'm sure they can handle the simple instructions in that youtube video for the princely sum of £1.50. The OP has nothing to lose at all. If it doesn't work or they cant source a gasket or re-seat the existing one with some plumbers silicone, they can buy a new fill valve which will come with said gasket.

WIAWSNB

Maffy, if you are certain you are now catching ever single drip, then there's no rush to sort this, and the loo can still be used. 

Swipe

Maffy52 said:

plumb1_2 said:

WIAWSNB said:

This might seem daunting, but is actually ok - just rip it open, 

I would use a Stanley type blade and cut the sealant off, then gently pull the board off.

thanks. Have just taken off the board. There is a drip from the inlet into the cistern, must be the source of the leak. It seems like nothing but the container I put underneath had 100 ml of water in about an hour, so must be this, see photo! Maybe this drip has been going on for a while, but I just never noticed before!

How would I go about 'tightening this connection up, I can't see how to get a spanner or wrench in the space (do I somehow lift up the cistern?)

Yes, due to such a bad design giving no access, you'll probably have to pop the cistern off and then tackle it.

Boohoo

Maffy in your 2nd photo the one of the leaky parts is that water droplets on the edge of the pan next to the tiles?

It may be the angle of the photo but looks like it to me.

As for the £600 plumber charge what is the hourly rate for a plumber these days, anybody know?

As Swipe is saying the cistern may have to come off to do a proper long term fix.

danrv

Easier to tighten the plastic nut if the flexi can be disconnected. It looks like it's been tightened up off centre.
With the cistern drained, water turned off and the flexi unscrewed, a regular toolkit socket could be used if there's space.

The spanner sizes are usually referred to as 1/2" or 3/4", 15mm or 22mm rather than the nut diameter. 
A quick nip up may stop the leak otherwise loosen and use some sealant. There'll probably be a rubber washer on the inside so worth checking that. 
A straightforward job for a plumber or competent Diy'er. Shouldn't be any need to remove the cistern but it's usually two bolts holding it in place.

The floor just needs to completely dry out and then be checked for any warping. Some wood hardener may help if the ply has softened.