regulations and school employee directions. Some of these extended and outof-school activities are carried on at night when fewer custodians or teachers, who might provide some supervision, are in the buildings.

1. School responsibility.

(a) School custodial employees should be on duty at all times when the building is open for use.

(b) Teachers in charge of or sponsoring evening groups should be responsible for their supervision,

(c) While the custodian usually does not supervise the activities of pupils or other building visitors, he should have definite authority to check any actions or activities which may materially decrease building safety.

2. Control devices.

(a) The custodian should serve as the "keeper of the keys." Master keys should not be made available except to designated employees.

(b) Use of some of the newer changeable lock barrels simplifies key control.

(c) The use of corridor barriers, either doors or folding gates, may help restrict evening occupants to designated areas. If not properly located and controlled, they might delay rapid evacuation in case of need. They should never be used as corridor blocks during regular schools sessions.

3. Various school and extended school activities such as school parties, school plays, school athletic events, and practice periods for plays, carried on out of regular school hours may create some serious fire hazards.

(a) The various activities may permit more freedom, and supervision is usually more lax.

(b) Open but unused parts of the building may invite loitering.

4. Community adults often object to controls in their use of their school. building. Smoking and lack of protection against misuse of electrical equipment or the use of flammable materials increase the hazards.

XIII. Building Structure and Fire Protection

TO OBTAIN GREATER FLEXIBILITY and to decrease obsolescence school administrators often ask for inexpensive buildings that can be abandoned and replaced after they have been used a few years. Temporary construction is not necessarily the answer to this request. Certain basic safety and protective features are essential in all school buildings. Lighter or cheaper construction may be feasible in some one-story buildings. In any except one-story buildings safety precautions require construction that is not temporary. We are concerned here primarily with fire safety. Property protection is quite important, but first attention should be given to the protection of the bodies and lives of the building occupants. Plant design and types of construction are important factors in fire safety.

Types of construction that offer many opportunities for fires to originate and spread, or designs that fail to provide ample exit ways increase the fire hazards for the building occupants.

Fires do occur in fire-resistive buildings. However, the spread of fire in such buildings is usually less rapid, and the probabilities of safe evacuation and of reducing property losses are greater than in non-fire-resistive buildings. Some non-fire-resistive buildings, if not too high and if properly designed can be made to provide a fair degree of fire safety for the occupants. Any building that is not and cannot be made fire safe should be abandoned. Parents, teachers, and school officials should understand that masonry exterior walls and slate or tile roofs do not make a building fire-resistive. Such buildings might have combustible interior construction, poorly protected exit ways and many other hazards that endanger the pupils forced to attend school in such buildings.

Some principles of building construction and fire safety

Certain basic principles of fire safety should be considered in planning all school buildings.

1. Fires do not start without fuel. Construction that eliminates or reduces the quantity of combustible materials in areas where fires are most likely to originate may prevent the spread of many fires.

2. Small fires may grow and become more dangerous as they spread. Construction that reduces fire spread may prevent major property losses and reduce personal danger for the occupants.

3. Facilities for safe ecavuation in case of fire decrease the fire risk for the occupants. (See sec. XIV for information on exits.)

Structural and design types and fire safety

It is possible to discuss here only a few of the structural and design types that affect fire safety.

1. Building height and construction affecting personal safety; some suggested minimum standards.

(a) Buildings of one story may be of almost any type of construction provided ample exit facilities are maintained and the dangers of flash fires eliminated.

(b) Buildings of two stories should have at least acceptable masonry walls and fire-resistive walkways from each classroom door to the outside. The term "fire-resistive walkways" means fire-resistive stairs and fire-resistive corridor floors, walls, and ceilings. Note that these are minimums and that other fire-resistive floors, roofs, walls, and partitions are desirable.

(c) Buildings of more than two stories, not generally recommended but sometimes necessary for schools, should be of fire-resistive construction throughout.

2. Types of construction and design.

Fire-resistance is a matter of degree. In many instances fire-resistiveness that will withstand a severe fire heat for 30 minutes may give opportunity to protect the occupants through evacuation if they are alerted

to the danger, although it may not protect the building. In some cases a resistance of a 4-hour rating is desired. Resistance that retards a fire and delays its spread gives the fire-fighting forces a better chance to control the fire.

(a) The term "fire-resistive school buildings" as used here refers to buildings having fire-resistive exterior walls, floors, partitions, and roofs constructed of noncombustible materials. The term as used here does not mean total fireproofness. It is understood that some combustible floor surfacing, trim, and contents may be found in these buildings.

(b) Masonry walls extending through the roofs of combustible buildings help confine losses to the areas in which fires start.

(c) Special hot spots or spots where fires are more likely to originate should be segregated from pupil-occupied areas by fire-resistive construction or distance. Combustible furnace rooms should never be located under classrooms or corridors.

(d) Areas such as auditoriums or gymnasiums where groups of people assemble should be at ground floor levels and so located that egress is direct or nearly direct to the outside.

3. Some structural factors affecting fire control.

(a) Wood shingle roofs, wood gables, dormers, and other combustible roof projections increase the fire hazards.

(b) Combustible attic areas create hazards. The danger is materially increased if ventilating ducts empty into the attic. If this combustible area is not cut into segments by fire walls, fires originating in one place may travel through the attic or be carried by these ducts to other parts of the building.

(c) Cracked walls may fail to check fire spread. Some poor bearing walls and hollow or light block partitions may permit fire to spread from one area to another.

(d) Parapet walls help reduce the exposure hazards.

(e) Unprotected steel girders or posts may bend when subjected to much heat and their deflection may open new areas to fire damage.

(f) Plaster on metal lath protects girders from excessive heat exposure and delays entrance of fire into concealed spaces.

(g) Old lumber affected with dry rot or by termite tunneling may furnish easily ignited fuel for fire.

Floor and other openings that affect fire spread

Fires not confined to their places of origin may spread to endanger all of a building and its occupants. The rate of spread is materially affected by the fuel available, the resistance encountered, and the help given by air currents. School fires normally spread by burning through combustible partitions and walls, through vertical openings from one floor to another, through horizontal openings from room to room, through open attics, and through cornices. Drafts in vertical openings encourage the transfer of fire from lower to upper floors. Ducts that provide combustible fuels for fire spread increase the hazards.

1. Floor and ceiling openings.

There are numerous vertical openings extending from floor to floor or even from basement to attic.

(a) Stairways should be enclosed. Open stairs invite an upward flow of heat, smoke, and fire to increase the hazards on upper floors. This flow may make the stair ineffective as an exit.

(b) Chutes and dumb waiters should be of fire-resistive construction or metal lined and capped. Each opening into these ducts should have self-closing doors.

(c) Hot-air and ventilating ducts should be of fire-resistive materials and should not empty into attic spaces. These ducts should extend

through the roof or be combined into one large vent in a fireresistive plenum chamber.

(d) Scuttle holes to attics should be covered with heavy covers, preferably self-closing.

2. Other opening hazards.

(a) Use of spaces between wood joists or studs as hot-air or vent ducts is hazardous.

(b) Use of corridors as return ducts for hot air or as ventilation exhaust ducts may cause them to serve as funnels for fire gasses and smoke that might create serious panic hazards for pupils.

3. Concealed spaces.

Openings into concealed spaces may permit fire to enter. In some of these concealed spaces detection and extinguishment are often very difficult. In some concealed areas where drafts may be created fires spread rapidly.

(a) Furred and hollow walls with combustible construction in them offer opportunities for fire spread.

(b) Open spaces under floors may also provide places for fires to spread. (c) Breaks in wall plaster offer opportunities for fire to enter concealed spaces in walls.

(d) Smoke and draft stops should be provided where feasible in such concealed areas.

(a) Fire doors prevent fire spreading from place of origin and to block off certain building areas as safety zones.

(b) Fire doors are desirable to segregate hot spots where fires might originate, in some cases with explosive effects, from the rest of the building. Furnace room segregation by fire doors illustrates one

use.

(c) Use of heavy fire doors in school corridors to prevent fire spread from one part of a building to another might delay pupil evacuation and is not considered desirable. The use of properly designed light-weight fire-resistive doors at stair well openings as outlined in the section on exits is desirable.

2. Types of fire-doors.

(a) Door action may be: automatic closes automatically when released
because of the action of the heat (the door may stand open at
other times); or self-closing-which is normally closed by some
mechanical device each time it is opened. Illustration: the ordi-
nary spring on a screen door is one type of a self-closing device.
(b) Fire doors may have either slide or hinge action closing. The
slide type is usually automatic.

(c) Fire doors should bear the approval label of the Underwriters' Laboratories and should be adapted for the use to which they are put.

(d) Wired glass fire barriers may retard fires long enough for pupils to leave the building. They are not usually designed to hold major fires and should not be installed for that prupose.

3. Installation.

(a) The framing around fire doors should be of noncombustible materials.
(b) Release of the fire door should be by some fusible link or burn-out
cord of a type that will provide positive action when needed.
(c) Doors to stair wells should be so arranged that they can be closed
by a moderate pull when desired without waiting for the heat
effect.

4. Maintenance.

(a) Doors should close easily and should not rub or bind.

(b) The release and the closing device should work properly.

(c) Fire doors should never be blocked open. Weight cords should not be tied back or looped over projections to prevent free action.

(d) Frequent testing of fire-door action is desirable.

Building finish

Even fire-resistive buildings can have fire hazards. Some of the inside finish in most buildings is of combustible materials. Certain insulating, acoustical, and drapery materials used in many schools are highly combustible. With proper selection, treatment, and use of these materials the fire hazards may be materially reduced.

1. Wood trim.

(a) Wood trim should not be used around fire door or wired glass window openings.

(b) Wood trim should not be close to steam lines or heat producing units.

(c) Fire-preventing impregnating and surface-coating treatments of wood and other combustible interior finishing materials seem to have some value in preventing a rapid spread of fire. Such treatments are not intended to provide continued resistance to intense heat.

2. Insulating and acoustical materials.

(a) Insulating materials vary in their fire-resistance. Some materials, such as spun glass, may have high resistance; while others, such as mineral wool bats with exposed ordinary vapor seals, have little resistance to fire spread.

(b) Untreated fiber-board acoustical materials may be combustible. The fiber-board or tile units should be securely attached, preferably to a solid background.

3. Miscellaneous.

(a) The use of protective or decorative strips of highly combustible
materials that might form fire runners should be avoided.
(b) It is also desirable to avoid the use of finishing materials that give
off toxic fumes when subjected to fire.

(c) Loose hanging drapes, untreated window shades, and cloth curtains
may become serious fire hazards.