Fireblocking is like putting up roadblocks inside your walls to slow down a fire. It seals gaps around pipes and wires, blocking fire from spreading between floors. This gives people more time to escape and firefighters more time to put it out.
Modern builders use toxic spray foams or caulks to meet fireblocking codes. These materials are cheap and fast to apply but they have big downsides. First of all, they're not even fireproof—they eventually burn and release harmful smoke. Secondly, they're carcinogenic: harmful for installers, occupants, future generations, and the environment. [cue sad trombone].
[cue happy fiddle] To solve this problem I reached for adobe (aka "cob") a traditional building material made of sand, straw, clay, and water, that behaves like a sculptural putty before it dries, and is actually fireproof.
I rallied my jubilant mini-carpenters and taught them how to properly portion the ingredients, and then how to mix it up in the proper, old fashioned way: by dancing on it barefoot as a family.
They then took the job of squishing the fresh cob down into the gaps very seriously, and did a fine job. The mini-carpenters ordered that Dad did the ceiling gaps, and they would do all of the floor gaps. Who was I to argue with the widsom of future generations?
I anticipated that the local building inspector might scratch his head when he came in for inspection, so I asked my buddy at the legendary Cob Research Institute to point me toward scientific studies that prove the fire resistance of cob, just in case. But lucky for us the sensible inspector understood that in a fireblocking contest, earth beats plastic every time.
+1 for ecotopia!
+1 for future generations!
-1 for fire spread!
-1 for cancer!
-1 for the landfill!