ROCKWOOL INSULATED PANELS: A COMMON MISTAKE ALL INSTALLERS SHOULD PAY ATTENTION TO.
SHORT OVERVIEW OF THE ISSUE
I’ve recently passed by a new sandwich panel installation just next to the place I live. It’s a drive-through entrance to the E.R. for ambulances: by the law, that building requires materials with excellent fire behavior. That’s why the building company chose to use Rockwool insulated panels. The city council allowed the use of a beautiful fire-red on the outer side to mark the entrance of the building.
FIRE-RESISTANT INSULATED PANEL
These types of insulated metal panels have the characteristics of fire resistance. That means the manufacturer had tested them to get an E.I. certificate. The test for getting the Resistance to Fire Certification is strict, and it takes into consideration different aspects, apart from the Fire Behaviour of the building element. In particular, the E.I. test considers the capability of the insulated metal panels to prevent the spread of toxic gas of combustion and stop the heat of the fire from crossing a wall. It aims to prevent or limit the spread of the consequences of a fire and safeguard human lives and the integrity of buildings. In particular, the test checks the weak part of any insulated panel, its joints. The joints are the weak part of sandwich panels because it is where an interruption of the insulation occurs.
The best way to improve the tightness of joints is to add two elements: gaskets and screws. The gasket has to be intumescent to avoid burning. The screws play the crucial role of holding the wall panels steady when the fire deforms the metal. The installer must place the screws close to the joints, one by each side. And here we go back to our Rockwool cladding: as you can see in the pictures, the tightening of the screws had been too hard. There is no need to tighten the screws so much that they deform the external metal sheet: once we make such a mistake, we can’t undo it.
The screwing must be firm but not too hard: once the gasket touches the metal, we can stop tightening.