Firewall restraint system

(1m or more from relevant boundary)

In certain applications it is necessary to include fire protection to some or all of the perimeter walls around a building. There are many fire resistant wall cladding systems available today, which attach to Zed or C Section rail systems.

The side rail system described below combined with the fire resistant cladding system have been tested and have achieved a four hour fire resistance.

Although testing was carried out on our rail system for four hours the period of resistance is solely dependant on the type of cladding materials used and their construction and therefore certification should be obtained from the cladding supplier.

single span butt arrangement (rails slotted)

Note: The detail below shows the rail on the outside of the columns, if they are fixed in between the columns then similar clearance is required, i.e. 31mm either end for expansion.

Note:  Each individual rail section must be able to expand.

Under fire conditions the side rails will expand. To achieve the necessary movement either the column fixing cleat or the rail is slotted longitudinally as shown in the detail below with 62mm clearance to allow for expansion. Note the slotted cleats are supplied by others.

It is important that all the fixing bolts are fitted with combustible washers which under fire conditions will collapse enabling movement for the rail to expand. This prevents buckling of the side rail system and maintains structure of the wall.

Note: When firewall sleeves and/or slots are used  m16 bolts must be adopted (18mm diameter holes)

Note: Eaves beams and primary structural steelwork must be fire protected when supporting the rails and cladding. Special rail support cleats are required to achieve the additional clearance between joints.
When an odd number of bays occurs with the sleeved system, i.e. a sleeve position falls on the wider joint, this is catered for by a heavier gauge rail in this position or special sleeves as shown in the table below.

firewall sleeve dimensions