Sandwich panels

Question 1

Describe a sandwich panel

Answer 1

an inner core sandwiched between, and bonded to, a membrane
eg facing sheets of galvanized steel, often with
a PVC facing for hygiene purposes.
The panels are then formed into a structure by jointing systems,
designed to provide an insulating and
hygienic performance.
The panel structure can be free standing, but is usually attached to the building structure by lightweight fixings and hangers.

Question 2

The most common forms of insulation in present

use are:

Answer 2

(a) Expanded Polystyrene (Eps),
(b) Extruded Polystyrene (Xps),
(c) Polyurethane (Pu),
(d) Polyisocyanurate,(pIr),
(e) Mineral Fibre (MRf).
However panels with the following core materials
are also in use:
( f ) Modified Phenolic (Ph),
(8) Foam Glass (Fg).

Question 3

In a fire what is the likely reaction of the core of a sandwich panel

Answer 3

1. delaminate between the facings
   and core material, due to a combination of expansion of the membrane and softening of the bondline
2. fire-spread within the panel
3. production of large quantities of smoke, before delamination
   has occurred.
   4.rapid fire-spread and lead to flashover conditions.

Question 4

What is the likely reaction of the fixings of a sandwich panel involved in a fire

Answer 4

1. If the fire starts to heat up the support fixings or structure to which
   they are attached, then there is a real chance of
   total collapse of the panel system.
2. If the ceilings of these systems are being used to carry loads, such as refrigeration or air-conditioning plant, the
   hazard caused by the collapse of the panel system will be further exacerbated.

Question 5

when
compared with other types of construction techniques
these panel systems provide a unique combination
of problems for firefighters, including:

Answer 5

(a) Hidden fire-spread within the panels,
(b) Production of large quantities of black, toxic
smoke and
(c) Rapid fire-spread leading to flashover.
( d) Collapse
( e ) Delamination of steel surface

Question 6

Design Recommendations for
Buildings Containing Insulating
Core Panel Systems

Answer 6

(a) Removing the risk,
(b) Separating the risk from the panels by an
appropriate distance,
(c) Providing a fire-suppression system for the
risk,
(d) Providing a fire-suppression system for the
enclosure,
(e) Providing panels with non-combustible cores,
( f ) Specifying appropriate materialdfixing and
jointing systems.

Question 7

The following are methods by which the stability
of panel systems may be improved, in the event of
a fire, although they may not all be appropriate in
every case. BIG ANSWER !!!

Answer 7

(a) The details of construction of the insulating
envelope should, particularly in relation to
combustible insulant-cores, prevent the core
materials from becoming exposed to the fire
and contributing to the fire-load.
(b) Insulating envelopes, support systems, and
supporting structures should be designed to
allow the envelope to remain structurally
stable by alternative means, such as catenary
action, following failure of the bond-line
between insulant core and facing material.
This will typically require positive attachment
of the lower faces of the panels to supports.
The building superstructure, together with
any elements providing support to the insulating
envelope, should be protected to prevent
early collapse of the structure or the envelope.
Fixing systems using low-melt point elements,
such as aluminium, should not be
used.
In designated high-risk areas consideration
should be given to incorporating non-combustible
insulant-cored panels into wall and
ceiling construction at intervals, or incorporating
strips of non-combustible material into
specified wall and ceiling panels, in order to
provide a barrier to fire propagation through
the insulant.
Correct detailing of the insulating envelope
should ensure that the combustible insulant is
fully encapsulated by non-combustible facing
materials that remain in place during a fire.
(8) The panels should incorporate pre-finished
and sealed areas for penetration of services

Question 8

With regard to design structure the following general

points should be borne in mind.

Answer 8

(i) Panels or panel systems should not be used to
support machinery or other permanent loads.
(ii) Any cavity created by the arrangement of
panels, their supporting structure or other building
elements, should be provided with suitable cavity
barriers.