Separating 2 x Units with a Firewall
As you can see from the bottom right hand picture, when we first pulled down existing ceiling, there is a gap between the top of blockwork and the top of the roof structure.
The purpose of building a firewall is to fill in this gap to protect each unit individually from each other. So if a fire starts in one, it has protection from the fire spreading to the adjoining unit.
As plasterers we have trained and are qualified to build these life saving walls.
You might see in some of these pictures below, the firewall protrudes out from the main flat firewall. Why you might ask? Well this is because the timber on those beams runs through to the unit adjacent, so therefore if we didnt sheet these timbers out this far and caulk them with the approved fire mastic(see below), then the fire would simply burn the timber through the flat firewall and continue burning on into the next unit on the other side of the blockwork wall.
The distance these timbers are to be sheeted and caulked is 600ml from main wall. This is the Australian Safety Standard we must use when constructing fire rated linings.
You can not see in these pictures but there is also special insulation called Fire Seal, that has also been installed along the top of the fire sheets for extra protection, and in any gaps that need insulating also.
The fire sheets used here are 16ml thick, quite heavy and awkward to cut. But thats a perk of the job, lol.
To prevent fire spread, all screw holes and any gaps have been sealed by approved fire mastic. This stops air getting through and smoke also.
Installing these walls is tedious, takes a lot of time, can be difficult at heights and is heavy work when constructing long and high walls(especially on scaffold). But with all that said it can be very satisfying too, as being the tradesman tasked with building it, you know that potentially the firewall you are building may just save someones property an even more importantly someones life, which makes all the work worth it.