Thanks for the reply
I sent Karndean an email asking if there were any products or material that they recommend NOT to use with/near/on Karndean flloring and this was their reply.
Good Afternoon Thank you for your enquiry. You were quite right in what you have heard, some rubber and plastic product can cause "plasterise migration" to the flooring which is impossible to remove. This is caused with "Man Made" rubbers and plastics such as cheap door mats, plastic dog beds and even flowerpots. I would suggest using either a hessian backed mat or, if you still wish a rubber mat it must be made from a natural rubber as opposed to man made. One company who produces these mats and knows are company well is Turtlemat. There website address is
Washable doormats and rugs from Turtle Mat (Official) I hope this answers your question but if you require any further information please do not hesitate to contact me. Kind Regards Liz Collinge Karndean International (UK) Limited Crab Apple Way Vale Park Evesham Worcestershire WR11 1GP