In this paragraph ‘internal linings’ means the mater ials
lining any partition, wall, ceiling, or other internal lining,
such as plasterboard, plaster wall coverings including
paper. Clearly hessian and materials such as polystyrene
tiles have the ability to release large volumes of heat and
thus would greatly affect fi re growth, whereas plaster,
plasterboard, etc. release heat very slowly and would not
adversely affect the fi re growth rate.