looked at a stone floor clean today and whilst chatting potential custy said she gets her carpets cleaned by a company and the job had gone wrong. The carpets are wool & very light coloured, essentially white, not Hessian backed or any other natural fibre so its not cellulosic browning. There are lots of dirty looking spots which look like some one has gone round with dirty water trailing a small amount into lines/circles. Its weird! never seen alkaline browning so could be that. The job value was £250 ish to do four bedroom carpets and a room downstairs which for west yorks area is not the cheapest. I know which company it was and looked them up on the net -possible truckmount although they did not say specifically they use a truckmount, they also say they do low moisture. Tried to get a description of the machine all she said it was noisy - not much help there I suspect it was a portable. She has had the chap back 3 times he says its where he has not flushed the cleaning fluid out and it has made a bit of an improvement by re cleaning but it still looks bad. She says she has given up on him now - could not believe she has not pursued him into making a claim. She said he had started to get a bit shirty the last time she rang him!!!
In short these marks are not orange/yellow/brown they just look a bit dirty I am going to ask via email when quoting for stone floor if she wants me to do a test area to try to remove but does anyone think its alkaline problem. The backing is polypropelene. What do you think?