The possible rate and extent of fire spread throughout a building once a fire has been initiated are of prime importance in fire protection. They are related to the characteristics of the individual building and its parts and can be adjusted over a wide range by the designer. The principal means at his disposal in limiting the extent of the fire is through the use of compartmentation (see CBD's 11 and 33), by which various parts of the building, including exits, are separated by constructions having suitable fire endurance. The designer may also have to consider how best to reduce the rate at which fire will develop and spread within a compartment. This is in part related to the flame spread characteristics of exposed surfaces of enclosing construction, and is the subject of this Digest.

當(dāng)建筑物發(fā)生火災(zāi)時，火苗傳播的可能速度以及范圍在防火過程中起著極為重要的作用。它們根據(jù)建筑物特征以及構(gòu)造而不同，設(shè)計(jì)者也可以對其進(jìn)行很大程度的調(diào)整，主要方法是采用分隔措施(見 CBD's 11 和 33)，即包括出口在內(nèi)的各部分都由具有合適抗火性的建筑隔離開來。設(shè)計(jì)者同樣也要考慮每個分隔間內(nèi)怎樣能夠減少火災(zāi)形成以及傳播的速度，這不僅與其外部構(gòu)造特點(diǎn)有關(guān)，同樣也是這一文摘的主題部分。
火的性質(zhì)以及在每個分隔區(qū)內(nèi)的傳播方式已經(jīng)在CBD 31 中討論過了。不同情況下，火災(zāi)的傳播也不同，但是經(jīng)驗(yàn)表明，建筑物內(nèi)部性質(zhì)很大程度影響著火災(zāi)傳播速度。內(nèi)部材料的可燃性決定著分隔區(qū)內(nèi)火災(zāi)產(chǎn)生的可能性以及傳播的速度。