[0001] This invention relates to fire resistant panels.
[0002] As safety requirements in industry increase, ever more sophisticated panel structures
meeting ever increasing specifications for use in resisting the advance of fires for
specified periods of time have been proposed. Panel structures are thus being proposed
which are increasingly expensive. Frequently, use is made of steel sheeting and of
sandwich structures containing cementitious material for this purpose. Technology
developed in the construction industry is occasionally extended to meet the requirements
of high specification fire resistance.
[0003] It is an object of the present invention to provide a relatively low cost high specification
fire resistant panel system which is fire resistant from both sides.
[0004] According to the present invention, there is provided a panel structure comprising
an opposed pair of panels each comprising two metal sheets separated by a filling
formed of cementitious material, the panels each having first thicknesses which may
be the same or different and, sandwiched between the panels, is a central insulating
board having a second thickness greater than either first thickness. In the preferred
practice, the two opposed panels will be identical in dimensions and structure.
[0005] In one panel embodying the invention, the opposed pair of panels and insulating board
are held together by fire-resistant adhesive applied to all mating surfaces.
[0006] A panel structure embodying the invention provides fire resistance by means of the
opposed pair of panels and fire and thermal insulation by means of the insulating
board. The fire resistant panels will protect the insulating board from direct contact
with the fire which would otherwise cause surface erosion of the insulating board
and reduce its insulating properties.
[0007] The fire resistant panels may typically be of a cement and steel sheet composite
such as that known by the trade mark "Durasteel". Such a composite will offer additional
useful properties, such as resistance to impact, moisture, ballistic and criminal
attack. The steel element of the composite will form a Faraday Cage which causes attenuation
of electromagnetic waves. Such composite boards are readily available and of relatively
low-cost. However other fire resistant panels may also be used if further specific
properties are required.
[0008] The insulating board is preferably a thermally insulating board formed of calcium
silicate of low density (260 kg/m
2) which will enable it to perform its insulating function at high temperatures. Other
materials can be used which provide similar properties. Calcium silicate board thicknesses
tend to be greater than those of many fire resistant boards and this is a desirable
property where insulating behaviour is required. Typically, fire resistant boards
as aforesaid can be manufactured with a thickness of as little as 6 mm overall to
be used with calcium silicate insulating board having a thickness of the order of
50 mm.
[0009] When built into an insulating fire barrier system, panels embodying the invention
can be held together by means of cover strips made from the fire resistant panel material
comprised thereby. The cover strips are preferably held in place by screws connecting
through to the fire resistant panel of the panel structure. Such structures are self
supporting and it is merely necessary for steel angles to be fixed to surrounding
masonry and panels to hold to the system in place. The panels may be cut to size to
suit the shape of the barrier to be formed and holes cut to accommodate services that
need to pass through the barrier. Joints between the panels and masonry may be sealed
with fire resistant compositions to prevent passage of fire. Similarly, the services
passing through the panel may be sealed with suitable fire stopping material.
[0010] For a better understanding of the invention and to show how the same can be carried
into effect, reference will now be made by way of example only, to the accompanying
drawings, wherein:-
Figure 1 is a perspective view of a panel structure embodying this invention; and
Figure 2 is a section through a joint between a pair of panels embodying the invention.
[0011] Referring to the drawings, Figure 1 shows a pair of fire resistant panels 1 and 2
each made up of a pair of thin steel sheets 3 and 4 between which is sandwiched a
body 5 of cementitious material. An insulating panel 6 formed of calcium silicate
is adhesively bonded to each such panel by means of a fire resistant adhesive.
[0012] Referring to Figure 2, a pair of panels 1 abut at a joint 7 over which are laid a
pair of cover strips 8 secured to each of the panels 1 by screws at positions 9, 10,
11 and 12.
1. A panel structure comprising an opposed pair of panels each comprising two metal sheets
separated by a filling formed of cementitious material, the panels each having first
thicknesses which may be the same or different and, sandwiched between the panels,
is a central insulating board having a second thickness greater then either first
thickness.
2. A panel structure as claimed in claim 1 wherein the two opposed panels are identical
in dimensions and structure.
3. A panel structure according to claim 1 or 2, wherein the opposed pair of panels and
insulating board are held together by fire resistant adhesive applied to all mating
surfaces.
4. A panel structure as claimed in any preceding claim, wherein the insulating board
is formed of low density calcium silicate.
5. A panel structure as claimed in claim 4 wherein the opposed panels have a thickness
of about 6mm and are separated by calcium insulating board having a thickness of about
50mm.
6. A panel structure as claimed in any preceding claim wherein each panel is a cement
and steel sheet composite.