FME graded stainless steel has superseded the old terne coated stainless steel due to the removal of the lead coating element of the steel,
over the years manufactures have altered the mixing of the metals slightly in order to keep the cost as low as possible whilst maintaining the toning down element
to create an almost lead colour once patinated. You can see by the photo’s we have attached a newly installed roof and the same roof 1 year old, showing the FME toned down.

It is also advisable to use 0.5mm thick on the roof sheets whilst using Met Matt (stainless steel) underlay, as this provides the flattest sheet possible; thus, keeping the chance of possible “oil canning” to a minimum.