Dark patches appearing on tiles

[markjg123]

I've noticed dark patches appearing on the wall tiles in my shower room. It's an internal room ventilated with an extractor fan. The installation is about 2 years old. The dark patches appeared after the shower had been used and have not disappeared after the moisture in the room has gone. Most of the darkening is appearing on tiles outside of the shower cubicle. Some tiles appear completely normal, whilst an adjoining tile is completely dark! Please check out the photos I've uploaded. Some of the excess moisture is running behind the skirting and collecting on the floor. Any ideas what is causing this and is it a problem apart from the inconvenience of having to mop up the small puddle of water from the floor?

UPDATE:

I think there might be a leaking cold water pipe from a sink in the bathroom directly above the shower room. If water is running down the inside of the wall (behind the tiles) could this cause the darkening? I can fix the leaky pipe, but will the tiles simply dry out if this is the problem?

Untitled

• markjg123
• 19 Aug 2014
• 1

Untitled

• markjg123
• 19 Aug 2014
• 1

Untitled

• markjg123
• 19 Aug 2014
• 1

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[foxhole]

Certainly fix any leaks, excess condensation will cause pooling, you may need a better fan and check it's outlet is not blocked with fluff.
I have windowless shower room and use a powerful 6" inline fan drawing on two vents to keep it condensation free.

 

[markjg123]

Thanks. I'll check the fan. I don't think it's probably powerful enough but I don't know how I can easily replace it. It's inaccessible.

Can you explain what "pooling" is?

 

[Diyisfun]

Water behind tiles, been there had it.

 

[markjg123]

OK. So I've fixed the leaky tap connector. No idea how long it's been leaking so plasterboard behind tiles could be absolutely soaked.

Did the dampness behind your tiles dry out without any additional intervention?

 

[Diyisfun]

I took them off, as they wouldn't dry, I had to leave them soaking in water for weeks so I could get the adhesive off, then I retiled as good as new eventually.
Mine were not on plaster board, some were on plaster & others on lathe & plaster wall, which I had to repair.

 

[markjg123]

That sounds like a total nightmare. I have a few spare tiles, so a repair job might be possible.