This appears to be a follow-on question to this.
http://www.theanswerbank.co.uk/Home-and-Garden /Question603373.html
(its best to attach your supplementary question as an answer to your original question - not raise a new question).
You don't say who has found it.
This problem can cause 'doming' of a flat floor so it rises in the middle. It is caused when groundwater gets under the concrete and reacts with the sulphur, making the material expand. The problem usually works the other way around. Viz "My floor is doming, why is it" - Answer - you've got sulphur in it.
Don't suppose some smart-a***d surveyor working on behalf of a buyer of your house is finding reasons why your house might have a problem, as a means to reducing the selling price?