In view of the fact that books will always remain combustible, and sensitive to injury from smoke and water, it is now generally conceded that all we need aim at is isolation, slow combustion through “warehouse-construction,” hollow walls, iron or steel shelving, and the like.
Outside iron shutters are considered clumsy, and not so good protection as distance from other buildings. Inside iron doors are frequently neglected, and tend to curl up in hot flames. Local fire regulations sometimes require protected doors through partitions—for which slow-burning wood, tinned, is preferred. These are often interposed between the stack and the rest of the building. The stack can be made more fireproof than the rest, without much extra expense. Its greatest danger, shared with other parts, is from crossed electric wires. Against these, careful installation by conscientious electrical experts is the chief protection.
Thoroughly fireproofing the boiler-rooms, ash-pit and waste-paper bin is a protection any building can have, and in many cases these can all be set outside. Heating-pipes can be kept from contact with woodwork or books, and can be protected with asbestos or otherwise.
Material is a great factor of danger or safety. Wood, unless treated chemically, is more dangerous than iron or stone, but inside iron needs protection from flame, lest it yield when most needed. In the San Francisco fire, brick and terra cotta withstood heat better than marble, granite, sandstone, or limestone.[218]
The great use now made of concrete for floors, ceilings, partitions, and walls renders modern buildings safer from fire, and is to be commended especially in libraries.
The roof is vulnerable and should be of non-inflammable material, fireproofed if possible. Sparks blown from neighboring conflagrations, lighting on an unguarded public building, give the greatest outside danger. Tar roofs are said to be non-combustible, when properly gravelled, but do not be too sure of them. Tile, slate, asbestos-shingles should insure you.
Elevators. These and lifts furnish in their shafts dangerous draft-flues for fires starting below. If there is any way to provide doors and trap-doors easily managed, to shut off every floor, one great danger of spread of fire is removed.
Glass. As outside shutters are objectionable, tough wire-glass, which does not break easily from heat, will furnish a measurable protection from outside fire, without materially diminishing light. Indeed it may transmit or reflect light better than large panes of plate glass, which shatter too easily.
Fire-buckets on every floor, prescribed in many insurance regulations, are not so necessary when there are water-taps handy everywhere, as recommended above. Fire extinguishers, however, are not superfluous.