I was in the carpet trade for 17 years and I have come across foam-backed carpets that gave off a rotten egg smell and had to be replaced but my mate has contacted me today to ask me if there was anything I could do about a hessian-backed carpet on the system 10 method of installation. Where the carpet is glued to the heavy-weight crumb rubber underlay to hold it in place. He says if he gets on his hands and knees to smell the carpet there is no odour but if the door is shut then the next day the eggy smell is back again. I could try Zybax Odourmaster but as there does not seem to be any bacteria involved I doubt if it will work. Has anyone else come across this problem?