Roof tiles (6)

I believe the answer is:
slates
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">roof tiles</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for slates that I've seen before include "Strongly criticises the roof tiles" , "Criticises severely using roof coverings" , "Abuses with roof tiles?" , "Thin layers of rock for roofing" , "Berates with roofing tiles" .)