Fire-resistance rated cross barrier in a <a href="//commons.wikimedia.org/w/index.php?title=Pipe&amp;action=edit&amp;redlink=1" class="new" title="Pipe (page does not exist)">pipe</a> tunnel of a <a href="//commons.wikimedia.org/wiki/Germany" class="mw-redirect" title="Germany">German</a> power plant. Nothing else would work here, not brick, <a href="//commons.wikimedia.org/wiki/Drywall" title="Drywall">drywall</a>, or cast <a href="//commons.wikimedia.org/wiki/Concrete" title="Concrete">concrete</a>. The <a href="//commons.wikimedia.org/wiki/Mortar_(firestop)" title="Mortar (firestop)">firestop mortar</a> was simply <a href="//commons.wikimedia.org/wiki/Pump" title="Pump">pumped</a> in and smoothed up. Holes were spared out for the actual piping and ductwork penetrations. These smaller holes are subject to motion and were thus filled with <a href="//commons.wikimedia.org/wiki/Thermal_insulation" title="Thermal insulation">rockwool</a> packing and then sealed with a <a href="//commons.wikimedia.org/w/index.php?title=Silicone&amp;action=edit&amp;redlink=1" class="new" title="Silicone (page does not exist)">silicone</a> <a href="//commons.wikimedia.org/wiki/Firestop" title="Firestop">firestop</a> caulking. Advanced firestop mortars afford superior dimensional stability (adhesion/cohesion) during placement, while in the plastic state.
<a href="//commons.wikimedia.org/wiki/User:Achim_Hering" title="User:Achim Hering">Achim Hering</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>