"r. T1R i~n 
son
CIRCULAR 49
MARCH 1926
Protecting 
the Farm 
Against Fire
1j~V
M\. I.. AI(:i1oI S \I I B. 
C11. NN IBBs
AGRICULTURAL EXPERIMENT 
STATION
of the
ALABAMA POLYTECHNIC 
INSTITUTE
iI. J. FII'NCIIESS, Director
AUBURN
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PROTECTING THE FARM AGAINST FIRES*
By
M. L. NICHOLS AND T. B. CHAMBERS
The census of 1920 values all farm property in Alabama at
$690,848,720. Of this amount, $415,763,862 is given as the value
of the land, $127,893,893 as the value of the buildings, and the
balance is the value of implements and livestock. This means
that over one-third of the farm property (when livestock and
implements are housed part of the year) is subject to a fire
hazard.
That this fire hazard is a real menace to the farmer's prop-
erty is shown by statistics. The Acturial Bureau of the National
Board of Fire Underwriters records the farm fire loss from
1918 to 1921 as $89,460,525, or $61,274 per day for the United
States. This should be increased by at least 25 per cent to allow
for unreported and uninsured losses. The average loss per
claim was $594.
To quote directly from their bulletin, Safeguarding the Farm
Against Fire: "Since there are slightly less than 6,500,000
farms in the United States, it is evident that one in every forty
had a more or less disastrous experience with fire in these four
years; or, to put it in another way, the number of loss claims
for the whole country was about equal to the number of farms
in the New England States, and this experience three-fourths
of the afflicted farms need not have had, for the reasons that
carelessness and lack of knowledge of fire hazards were chiefly
responsible."
It is true that fire hazards vary with different farms, but
this variability is largely within control of the farmer. The
following information has been compiled and supplemented
with experimental data as a part of the work in connection with
rural electricity studies.
SOURCES OF FIRES AND PREVENTIVE MEASURES
The causes of fires on farms as discussed in this bulletin
are listed as the more important by the fire underwriters. A
knowledge of fire-resisting construction is necessary to obtain
the maximum safety but an understanding of a few simple
points of construction will enable the farmer to see that his
buildings are so constructed as to eliminate a larger part of the
hazard. A "fire consciousness" is necessary to prevent careless-
ness which, in many cases, is criminal since human life is fre-
quently involved.
Lightning. -Lightning ranks first as a cause of farm fires.
* Investigational work done on funds provided by the Alabama Power
Company.
The National Board of Fire Underwriters reports 
that over 18
per cent of the fires recorded in' 
the period of 1918-1924 was
due to lightning. Crosby, Fiske, and 
Forster in their Handbook
of Fire Protection (D. Van Nostrand 
Co. 1924) state that in an
analysis of over 40,000 rural 
fires 51 per cent was found 
to be
due to lightning.
A building properly protected by rodding 
is virtually im-
mune from damage by lightning. The 
essentials of a properly
rodded building as set out by the National 
Fire Protection As-
sociation are:
"That the conductors be constructed of iron or copper, and
copper cables must have a weight of not less than 3 ounces 
per
foot or 187.5 pounds per 100 feet. For star section steel, 
the
weight must not be less than 320 pounds per 100 feet in length
and must be provided with a protective coating of zinc, or other
approved material. The couplings must be of copper or brass
of substantial construction, working upon the threading, crimp-
ing, or clamping principle. Set screws are not approved. The
air terminals must be of the same construction as the conductor
when made of steel or of copper tubing having an outer diam-
eter of at least 5/% of an inch, and a wall thickness of .032 inch.
The point should be solid, terminating in one or more points,
and provided with a screw- cap or dowel."
The efficiency of a rod system depends upon the thorough-
ness with which it is grounded. One of the following methods
should be used:
(1) Where there is a system of underground metal water
pipes, the rods may be grounded to this by a brass screw plug
with the rods soldered to the pipe, or by putting clamps around
the pipe and screwing the rods to the clamps.
(2) Burying a plate of 16-guage copper 1 yard square at
least 8 feet in the ground, embedded in coke or charcoal to hold
moisture.
(3) Extending rods into permanently moist earth where this
can be reached readily.
General Suggestions
Air terminals are required on or within two feet of all high
points such as chimneys, gables, spires, cupolas, etc. Terminals
should not be over 25 feet apart along ridges. Elevated tanks
or stacks over 60 feet high require 2 rods and 2 grounds. The
minimum number of grounds per building is usually two, which
will suffice for 6 points. Three are required for 12 points.
It is advisable to ground metal roofs, ventilators, and pipings
which come close to outside walls, clotheslines, or metal con-
struction. Wire fences also require rodding. Horses and cattle
frequently drift along in a storm to a fence which may be
highly charged if not grounded. To ground it a cable equal to
a No. 9 wire should connect with each horizontal wire of
the fence and extend at least three feet into the ground at every
corner. 'tis wire should extend a few inches above the fence
to prevent strokes in this vicinity. Where a fence connects with
a bunilding, the fenice sh~ouIld be well groundledl and, in adldition,
the groulndinlg rodl of the b~uildling sh1ouJld be connectedI with the
fenice.
Defective Chimneys. -Fires originating from defective chini-
neys are net inl implortance to lightning. In the four-year
p~eriodl previoutlIy mentioned defective chimneys cauisedl 12 per
centi of the to tal1 loss. ('h ila mey fires are p~articullarly danger-
ous as they usually start in an attic or other concealed place
anid gainl great headway biefore they are detected. Fig. 1, page 5,
gives a plan for a reasonably safe chimney.
The essen tiails of an ordinance p~rodIuced by the National
B~oardl Comintltee on the Construction of fluildings follow:
"(a) Brick chiia neys 3:1 inches thick; single thickness con-
crete blo~ck; stone chimneys 8 inches thick; 0or rubble 12 inches
thiick, shli d, in all cases, hmave a fire clay flute linlilg.
The Ullilnlc> that is~ not) solidI to the~ groundi is aiway s a lIenelI(.
Th ire in thuis picttur started from this chiminey, probably duel to
the settling or' sliikage of tlimberis sup~portinlg it.
F'or fuirtherinfIofr1nation on lightning protection, see ht'ehnological
Paper No. 56, Bureau of Stand ards, D~ept. of Comnmerce, Washington, I). C.
Mon-Nie She[f
If flue liningqi
no* used al
wait--, houldtzbe
a" +h ik.
PLA3 AT TOP
Linin
Keep all wood Flue LininC Q
FireBraa4 least fZ" from
brick and fill
Near~h pace with non-
Headers .- con-dus+iblI- 
rno+
~F~j~e~t4Trimmer Arc~h
M*ove
+ AT FLOOR.
A~h Pi-i Door
E uVATIO M 5ECT IO N
FIG. 1
6
"(b) For dwellings, flue linings may be omitted 
if walls are
8-inch brick with inner course refractory brick.
"(c) Chimneys shall not rest upon or be 
carried by wooden
floors, beams, or brackets, or be 
hung from wooden rafters.
Iron brackets or stirrups attached to wooden construction 
shall
not be used to support chimneys. In frame 
buildings, chimneys
shall always be built from the ground up, or rest on basement
walls.
"(d) Chimneys shall be built upon concrete or masonry
foundations properly proportioned to carry the weight 
imposed
without danger of settling or cracking. The foundation for an
exterior chimney shall start below the frost line.
"(e) A special cement-lime mortar is specified for chimney
construction.
"(f) Minimum clearance of wood joists, beams, 
and rafters
from face of chimney is 2 inches, and behind a fireplace, 
4
inches.
"Chimneys set on brackets have a tendency to settle and
open up cracks from which sparks can issue. Poorly built
chimneys may be rocked by the wind and dangerously cracked."
Sparks on the Roof. -Closely related to defective chimneys
is the fire caused from sparks on the roof. 
This is responsible
for over 7 per cent of our rural fires. There are two 
means of
reducing this hazard. First, by putting on a fire resistant 
roof
of metal, slate, or any of the prepared composition roofs which
have the underwriter's approval. Many of these prepared roofs
are covered with various materials, such as slate, which 
give a
satisfactory resistance. The second safety point is a screen
over the chimney which will prevent any large sparks or balls
of burning soot from coming over on to the roof. This plan not
only has the advantage of being cheap and efficient, but also
prevents the entrance of birds and insects into the chimney at
times of the year when they are not used.
Fig. 1, page 5, shows a plan of such a screen. However,
these devices should not take the place of regular cleaning of
chimneys. A handful of table salt scattered over a fire when
the draft is on has the effect of reducing soot deposit.
Stoves and Heating Equipment. -Ranges, and coal and wood
stoves offer more or less of a hazard. They should be installed
with certain safety features in mind. First, they should always
have a ventilated place under them. Ordinarily the legs will
give this protection. When within 24 inches of a partition, the
partition should be protected for a space equal to the length or
width of the range, plus 6 inches on each side and extending
from the floor to the ceiling where pipes occur, and not less
than 4 feet high elsewhere. This may be effected by cellular
asbestos not less than 1/2 inch thick, covered with metal lath
and plaster. Iron or tin may be used if an air space is 
left be-
hind it. Stovepipes should enter the chimney horizontally 
and
pass through an insulating thimble which fits snugly. The pipes
should not be closer than 24 inches to any woodwork or closer
than 6 inches to metal lath and plaster. They should not pass
through combustible floor, roof, or partition unless a section is
removed and suitable insulation of at least four inches of non-
combustible material with ventilation provided. Smokepipes
should not be permitted in closets or concealed places. In ad-
dition to these precautions, a floor protection of zinc plate ex-
tending at least 18 inches in front of stove and 12 inches beyond
each side and back to wall should be provided.
Matches.-The fourth fire hazard is the common match.
This danger is greatly increased when smoking is permitted
around farm buildings. This danger may be eliminated largely
by the use of safety matches and by keeping matches in earth-
enware jars.
Spontaneous Combustion. -The fifth fire hazard is spontan-
eous combustion. This is a partly preventable cause. Crops
which are stored in a partly cured condition give a rise of
temperature, due to bacterial and chemical action. Frequently,
this is sufficient, if the heat is stored up, to ignite the material.
Common salt scattered through the mass will render it less
likely to overheat. Linseed oils and cottonseed oil are both
apparently conducive to this action. Oily clothes and waste
are subject to similar action, and rags used in painting have
been known to start fires resulting in great damage.
Gasoline. -Gasoline ranks sixth as a source of fire. Safety
measures should be taken for the storage and handling of this
highly inflammable material. It should always be kept away
from matches and open lights. Blue flame kerosene stoves are
as satisfactory, and safer. Gasoline should not be stored in the
farm buildings. A special outside storage is desirable. Under
ground is better. A separate garage is not only safer but prob-
ably cheaper in the end. An automobile or truck should not
be stored in the barn with hay and other inflammable material
under any condition.
Lighting. -Lanterns and lamps around the barn bring in 
an
element of danger. Electricity greatly reduces this hazard but
all wiring should be carefully installed according to the na-
tional electric code. Circuits should be fused carefully with
fuses of the prescribed amperage. Properly installed wires
with porcelain tubes and brackets are of little danger. For
safety, they should be in conduit. Nothing should be allowed
to rub against them. All switches around the barn should be
in iron-clad boxes, operated externally and kept tightly closed.
8
Good Housekeeping. -Among the 
other numerous but less
important causes 
of fires are many which 
may be eliminated
by good housekeeping. 
Rubbish or refuse piled 
in corners are
a minor menace. Carelessness 
in handling ashes frequently 
re-
sults in fires, as they 
may contain hot coals 
which will smolder
for several days. When 
these are dumped in 
a wooden barrel
they are a prolific source 
of fires. A national loss 
of over
$11,000,000 has been attributed to this cause in one year.
GENERAL FIRE PROTECTIVE CONSTRUCTION
Most farm buildings in 
Alabama are constructed 
of wood,
the high cost of other materials 
making their use uncommon.
Obviously it is important to consider 
types of construction which
will reduce the fire hazard to a minimum. Laist (in 
the Journal
of Agricultural Engineering, Oct. 
1924) gives three distinct ways
of doing this. First, by adopting as far 
as possible the principles
of mill construction as used in industrial buildings. 
Second,
avoiding concealed spaces or ducts, using fire 
stopping devices
and avoiding small members wherever 
practicable. Third, a
limited use, or employment in extra hazardous positions, 
of fire
resistive construction, which consists of wood covered with 
a
material which offers resistance to fire; for example, metal lath
and plaster.
Tin cGin%(.hed naO oube 
!op Join.
APP oVED TtN CLAD FI E DOO
MAX MUM A EA = aZO q.FT.
FIG. 2
Concealed air spaces, the use of timber of large 
cross sec-
tion, and the very large floor areas without the intervention 
of
fire walls are avoided in mill construction. The 
mill type of
construction is generally accepted as one of 
superior qualities
and offers no greater hazard than the so-called "fire-proof"
construction; and when provided 
with a sprinkler system it ob-
tains the same insurance rating as if "fire-proof."
9
The actual value of this construction can be seen when the
difficulty of starting a fire, except at the edge of a heavy tim-
ber, is considered. For this reason the corners are chambered
or rounded. It is also difficult to start a fire on a solid plank
floor. Actual tests have shown that unprotected timber 
columns
will stand longer than unprotected steel columns when sustain-
ing a load in the presence of the heat of a fire.
The merit of this type of construction for the farm lies chiefly
in allowing time for the farmer to save his livestock and equip-
ment. No type of practical construction Will withstand the heat
of a burning mow of hay. However, when the animals are
housed on the ground floor of a barn, the upper part of which
is used as a storage for hay, a heavy beamed ceiling with tight
two-inch plank for flooring will hold back the flames for a
considerable period of time. This is particularly true if fire
doors are installed between the two floors. These doors should
be constructed so as to close on their own weight. If they are
t'ouble tPlcae bo
P\as+e r
Arrows show
pa+h o- flamesI
ac-+as r e
FIQE 5E.5 TIVE WALL 1iON-2Eb15TIVE WALL
FIG. 3
10
kept open they should be suspended with a cord of fusible link
which will burn through readily and permit the door to fall
shut, thus cutting off the fire from the lower portion. A sec-
tion for this type is shown in Fig. 2, page 8.
Plans embodying the essential points of resistive construc-
tion in house walls and partitions show the essential details of
resistive construction (Fig. 3 and Fig. 4). When metal laths and
plaster are properly used on walls and ceiling, tests made by
the underwriter's laboratories show that fire will be confined
one hour to the room where it started. This not only allows
time for escape and for the removal of property, but frequently
holds the fire to proportions where equipment available to the
farmer will be able to cope with it.
Further details of this construction may be obtained from
the Association of Metal Lath Manufacturers, 123 W. Madison
Street, Chicago, Illinois. The underwriter's data show that 96
per cent of all fires originate within the building involved.
This shows the value of interior protection.
Metal La+h
3
Y4 P l0ter-+
e merit Bse
Y,,4 70+ I
FIG. 4
11
FIRE CONTROL MEASURES
It is always easier to prevent a fire than to fight 
one. Next
to prevention, the best thing is to put it out while it is small.
Fires start in a small way. If the construction and arrangement
of a building are such as to confine them to small proportions
for a period of time sufficient to allow the farmer 
to bring into
play equipment for the extinguishing of small 
fires the risk is
naturally reduced.
Every farm should have some means of extinguishing fires.
The amount of money which should be invested in this equip-
ment depends upon the value of the buildings. A brief descrip-
tion of means to this end follows:
Buckets of water hung in convenient places are the cheap-
est and simplest fire extinguishers. There should be at least
two of these buckets at a place. They should be used for fire
only. To keep them from freezing, they should contain a solu-
tion of calcium chloride (common salt corrodes the bucket), and
a thin film of oil should cover the water to prevent mosquitoes
breeding. A barrel of water containing a stock of several buck-
ets is a very satisfactory arrangement.
Common 21/2-gallon portable extinguishers of types approv-
ed by the fire underwriters should be available. These should
be located in accessible places and be recharged at least once
a year to, insure being in operating condition. There should be
at least three in the house and two about the buildings. If
oil or grease is present, extinguishers containing carbon tetra-
chloride or some similar smothering chemical are needed. Dry
powders are of little value. A bucket of sand is satisfactory
for grease or oil fires. An axe and a ladder of sufficient length
to reach the highest roof should be convenient.
WATER SUPPLY TESTS AT AUBURN
When there is an automatic pressure or gravity water sys-
tem on the farm it is possible to extinguish a small fire if garden
hose is available. Frequently, when a fire has become of such
proportions that the available water will not extinguish it, other
buildings can be saved by this means.
To determine something of the value of this equipment, the
Alabama Experiment Station made a study of a special instal-
lation designed for the purpose of determining the variables
entering into the use of farm water supply for fire protection.
The facts obtained from this study follow:
The source of water supply on the Station farm where these
12
tests were made consisted of a shallow well which 
contained,
under normal conditions, from 
500 to 600 gallons, depending
upon the conditions of the water 
table in the soil. At the time
the tests were run, which was 
during an unusual drought, only
a little over 500 gallons were available 
in the well when
pumping was started. However, 
as the pumping proceeded at
a rapid rate, the water channels supplying 
the well were opened
up so that as much as 
1460 gallons were pumped 
from it in 13/4
hours. This effect is to be expected as 
an accompaniment of
large capacity pumping. From observations of 
a number of
wells equipped with farm water supply systems, 
this well is con-
sidered typical of those of the Piedmont and Coastal 
Plains sec-
tions of the State. *
Fire Fighting Equipment
The equipment tested consisted of a Gould "Pyramid" pump
attached to a 36 by 120 inch electrically welded horizon-
tal tank of 530 gallons operating capacity, equipped with
standard 100-pound pressure guage, a 14-inch glass water guage,
and 2-inch pipe connections. All pressure readings were made
on this guage.
The pump is one of the larger standard types used for do-
mestic water supply and is known as a Pyramid Outfit 0. It
has a 4-inch piston, 5-inch stroke, and a capacity of 1260 gal-
lons per hour for 150-feet elevations, with a 2-inch suction and
discharge pipe. The pressure was controlled by an automatic
pressure regulator governing the operation of a 11 h. p. stand-
ard motor. During the tests this was set to start the pump when
the pressure in the tanks fell to 35 pounds and to cut out at 45
pounds.
The entire equipment is located in a concrete pump house.
The pump is 42 feet from the well and 12 feet above the normal
surface of the water. There are three fire plugs, respectively
74 feet, 80 feet, and 95 feet from the well. Each has 3 right
angle bends made by standard 2-inch elbows.
The hose used was permanently connected at the fire plugs
and housed in hose boxes especially constructed for this pur-
pose. These boxes are closed with a breakable glass door so
that the hose is accessible and ready at any time for immediate
service.
The entire cost of this outfit, exclusive of pump house, is
estimated to be between $450 and $500, or about $150 
more than
ordinary installations of smaller capacity. When a relatively
large amount of water is needed, as on larger plantations, and
* For detailed information as to water supply of Alabama, see bul-
letin of the State Geological Survey, Underground Water Resources, by
Eugene A. Smith.
13
where the investment in buildings is considerable, 
the value
of such equipment is unquestionable. Exact 
data are not avail-
able as to the percentage of reduction of 
the fire hazard; but,
in the opinion of the writers, it is at least equal 
to the protec-
tion given in many small towns by volunteer companies 
and
with much more expensive equipment.
Test of Installation
During the tests, a standard water meter was 
attached be-
tween the plug and hose, and the volume of water recorded.
The height to which the water could be thrown was measured
by triangulation and the range measured by a tape. The 
pres-
sure was recorded at the tank, and the time measured by a stop
watch. One hundred feet of two-inch cotton fire hose was used
with %, , % and 5/16 nozzles. The tank being between the
hose and the pump made it possible to use the pressure 
in the
tank to throw a large quantity of water in a few minutes. With
the %-inch nozzle 944.5 gallons of water were thrown in 28
minutes, which is at a rate of approximately 2020 gallons per
hour. This is at a rate of 760 gallons above the capacity of the
pump.
However, in this case, the pressure in the tank fell very rap-
idly and at the end of 8 minutes only 15 pounds were registered
at the tank. This pressure gave a range of only 20 feet, which
was too short for practical fire fighting. With the 1/
2
-inch noz-
zle, the pressure fell to 15 pounds in one-half hour and con-
tinued at this point for the next half hour when the test was
stopped. With the half-inch nozzle, 15 pounds pressure gave a
minimum effective range of 22 feet. For many purposes, this
would be an effective use of water, as 1583.8 gallons were de-
livered in one hour.
The 
3
/-inch nozzle delivered 1965 gallons in 1 hours, at
which time it was delivering 21 gallons per minute at an effec-
tive range of 24 feet. This being the capacity of the pump, this
flow and this range were maintained constantly until 2264.5
gallons were delivered at which time the test was stopped.
Calculations from the above data showed that a 5/16-inch
nozzle would give approximately the capacity of the pump at
43 pounds pressure. In tests, a nozzle of this capacity main-
tained a stream of 21.75 gallons per minute, at an effective range
of 38 feet, for one hour, with 600 gallons remaining in the tank.
The nozzle used in this test was so made that the top could be
screwed off to give a larger flow for a few minutes. With the
tip off, 224.5 gallons were delivered in 4 minutes and 10 sec-
onds. This is slightly more than twice the capacity of the pump.
A tip which would be adjustable would be preferable to the one
above described, as no time would be lost in getting the tip on
14
and off. The selective rate appears to be particularly desirable
when the total amount of water available is limited and must
to be used to the best advantage.
The 5/16-inch nozzle outfit was considered as the 
most de-
sirable equipment, for it gave the operator the opportunity of
using approximately twice the capacity of the pump for several
minutes to get fire under control, or a continuous stream at high
pressure could be used to protect one building from another
burning close to it.