The Delta independent., 1909-03-26
Concrete Floors.

LOO nucn care cannot De exercised
in preparing the foundation for con-
crete floor. This should always be well
drained and firmed, to a depth of from
six to eight inches below the concrete.
1t pays to thoroughly tamp this
foundation before putting on the mix
ture. If the soil contains great deal
of clay, it may be necessary to remove
part of it and to fill in with broken
stone, gravel or cinders to within four
or six inches of the proposed finished
surface, depending upon the thickness
of the floor. Blind drains of coarse
gravel or tile may be laid from the
lowest points in the excavation to car
ry off any water that may accumulate
beneath the structure.
For the construction of the ordinary
stable or barn floor, which is not to
carry any great weight, the following
proportion is to be recommended for
the concrete base: One part cement,
two and one- half parts clean, sharp
sand, and five parts of loose gravel
or broken stone. This should be fin
ished on the surface with a one to one
and one-half inch layer of a mixture
of one part cement and one and one
half to two parts of clean, sharp sand.
The total thickness of this floor must
be from five to eight inches. depned-
ing upon the load it is to carry.
For engine foundations. floors, OF
driveways over which heavy loads
pass. the following proportion is to be
recommended: One part cement, two
parts sand, and four parts broken
stone or gravel.
For all large floors. it is advisable
to place the concrete in sections not
to exceed six feet square. This may
be done by placing two-inch plank
of width equal to the desired thick
ness of the floor on edge as box in
which the concrete is tamped until
water begins to show on top. Make
several of these forms, holding the
plank in place by means of stakes
driven into the under surface. CThese
stakes should be driven on the outside
of the form SO they may be easily re-
moved after the concrete has partly
set and the planks have been taken
out.) Fill alternate forms at first,
tamp the concrete thoroughly, especial
ly the edges. AS soon as the concrete
has partly set, remove the plank and
fill in the forms not filled at first
Mark the side plank to show exactly
where the joints come.
The finishing coat should be spread
on before the concrete has set. To
make this of uniform thickness it is
best to place either one or one-half
inch wood strips as is desired, on top
of the concrete over which a straight
edge may be run. Smooth with a
trowel, for smooth surface, or with
wooden float for rough surface.
Groove exactly over the joints of the
concrete so as to level the edges of
each block.
Do not trowel the surface too much,
as it tends to separate the cement from
the sand and Injuries the wearing sur
face.
The floor should be constructed with
slope enough to carry all liquids to GER
tain points from which it may be
drained.
Protect the new floor from the di-
rect rays of the sun, currents of air;
and frost, and keep constantly moist
ened for several days. Water is very
important in the curing iof concrete
constructions, and must be literally
used.
Use nothing but the best cement
that can be obtained. The sand should