Electrical Conduit risers, seen inside <a href="//commons.wikimedia.org/w/index.php?title=Fire-resistance_rating&amp;action=edit&amp;redlink=1" class="new" title="Fire-resistance rating (page does not exist)">fire-resistance rated</a> shaft, as seen entering bottom of a <a href="//commons.wikimedia.org/wiki/Firestop" title="Firestop">firestop</a>. The firestop is made of <a href="//commons.wikimedia.org/wiki/Mortar_(firestop)" title="Mortar (firestop)">firestop mortar</a> on top, rockwool on the bottom. Conduit are pipes used to protect <a href="//commons.wikimedia.org/w/index.php?title=Cable&amp;action=edit&amp;redlink=1" class="new" title="Cable (page does not exist)">cables</a> from damage.
<a href="//commons.wikimedia.org/wiki/User:Achim_Hering" title="User:Achim Hering">Achim Hering</a>
2006-11-10
<span class="int-own-work" lang="en">Own work</span>