PRICELESS medieval floor tiles at Rievaulx Abbey, near Helmsley, North Yorkshire, are being protected from winter’s icy blast using a “turf sandwich”.

English Heritage is investigating a new way of protecting the rare ceramics, mostly dating to the 14th century, from damaging frost, which could accelerate decay if left unchecked.

The green and brown tiles are the last survivors of the thousands which once adorned the church floor at the spectacular 900-year-old ruin.

Until now ice has been kept at bay using polystyrene panels and plastic sheeting. But this winter a more natural solution is being tested. Grass turf combined with a waterproof barrier and a breathable membrane has been laid over the tiles, creating an insulating layer while also allowing air to circulate.

Mark Douglas, English Heritage properties curator in Yorkshire and the Humber, said: “Over recent weeks the grass ‘duvet’ has been vital.”