Black stain on the carpet

Hi guys, since we've lived here theres been a bizarre dark stain on the carpet. Is seems to get larger over winter, its almost like the guys before us have spilt oil everywhere and it just keeps coming back.

I have shampooed the carpets and it faded it slightly, but now as I'm looking down it is worse with very defined edges around it. Its winding me up now, What will get rid of it???

Thanks

It may be coming from the underlay. Have you managed to lift it to see if it's coming from below the carpet?

Have no idea how to get it out but does sound like its something coming from under the carpet!

Hello, the lounge carpet has no underlay, its just cement floor with these nasty brown tiles all over the house. So I dont even know when the carpet could be sucking this stuff up from?

We are getting new carpets fitted soon and I dont want this stain to come back on our new carpets. We will have underlay so hopefully this will lift it away from the floor enough? I dont know, Can I wash the tiles with bleech or something?

Sounds like it could be some kind of mould. The hard floor might get a bit damp during the colder months, so if there's no underlay it would come straight through onto the carpet...

So how do I stop it? Or how can I make sure it doesn't happen on our new carpets?

~Perhaps a weather resistant coating on the tiles before the new carpet is put down.

Hi wuffle, where can I buy some of that stuff?

I think some carpet fitters put down plastic sheeting under the underlay, just to provide more protection against infiltration (word of the day ) of moisture. That might do the job..?