We have just had a gas safety check done on a property that we rent out, and the comment was made that the supply gas pipe is not sleeved and needed to be done. The gas pipe comes up through the concrete floor and the pipe is made of steel. The house was built in the 1930's so my question is does this work have to be done. On previous gas safety checks the gas engineers have never mentioned that the pipe had to be sleeved. Can you please advise