▁called ▁an ▁ad obe ▁floor , ▁is ▁a ▁floor ▁made ▁of ▁d irt , ▁raw ▁earth , ▁or ▁other ▁un work ed ▁ground ▁materials . ▁ ▁It ▁is ▁usually ▁constructed , ▁in ▁modern ▁times , ▁with ▁a ▁mixture ▁of ▁sand , ▁fin ely ▁cho pped ▁st raw ▁and ▁cl ay , ▁mixed ▁to ▁a ▁thick ened ▁consist ency ▁and ▁spread ▁with ▁a ▁t row el ▁on ▁a ▁sub - sur face ▁such ▁as ▁concrete . ▁Once ▁dry , ▁it ▁is ▁then ▁usually ▁s atur ated ▁with ▁several ▁treat ments ▁of ▁a ▁dry ing ▁oil . ▁ ▁Ben ef its ▁▁ ▁Vari ety ▁of ▁colors , ▁text ures , ▁and ▁materials ▁ ▁Can ▁be ▁installed ▁over ▁nearly ▁any ▁sub f lo oring ▁ ▁Integr ates ▁well ▁with ▁in - floor ▁radi ant ▁heat ▁tub ing ▁ ▁One ▁of ▁the ▁che apest ▁flo oring ▁methods , ▁green ▁or ▁otherwise ▁ ▁History ▁Ear then ▁flo ors ▁were ▁pre domin ant ▁in ▁most ▁houses ▁until ▁the ▁mid ▁ 1 4 th ▁century ▁in ▁Europe , ▁and ▁persist ▁to ▁this ▁day ▁in ▁many ▁parts ▁of ▁the ▁world . ▁ ▁In ▁medieval ▁times , ▁almost ▁all ▁pe asant ▁housing ▁had ▁ear then ▁flo ors , ▁usually ▁of ▁hard pack ed ▁d irt ▁to pped ▁off ▁with ▁a ▁thin ▁layer ▁of ▁st raw ▁for ▁warm th ▁and ▁comfort . ▁▁ ▁In ▁China , ▁most ▁c ott ages ▁and ▁smaller ▁houses ▁also ▁had ▁ear then ▁flo ors , ▁made ▁of ▁ram med ▁earth ▁and ▁se aled ▁with ▁raw ▁lin seed .