Roofing slabs (5)
I believe the answer is:
tiles
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">roofing slabs</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tiles that I've seen before include "Thin flat slabs, for roofing perhaps" , "Glazed rectangles used to cover walls or floors" , "Thin flat slabs of fired clay" , "Small oblong slabs used in roofing" , "Roofing materials" .)