Civil Engineering Reference
In-Depth Information
You will inevitably find that it will
be necessary to fit a floor joist exactly
over the top of the pin from the stump
so the top of the bent pins are not to
protrude above the top surface of the
bearer. Particularly when using
hardwood bearers it will be necessary
to chisel a 'V' in the top of the bearer
to accommodate the pin in its bent
position. When bending the pin, first
hit the pin at the point that it
protrudes from the bearer. Do this
while holding the bearer tightly down
onto the top of the stump. Once you
have completed the process of fitting
the bearers over the material used as a
moisture barrier, you should not be
able to move the material.
Figure 3.7
Pins of concrete stumps are bent to the left and
right of the bearer
Fitting bearers tightly to the stump
If the bearer is bowed off the stumps you could get an assistant to sit on the bearer. This
is one time that to have a BIG assistant is beneficial. You will find that you too can put
your weight onto the bearer by sitting or squatting on it while you bend down the pins.
If the moisture barrier on top of the stump can still be moved, you need to force the
pin more tightly down onto the bearer. Again start hammering the pin at the bearer with
5-10 mm progressions along the pin. It is the tension of the pin against the edge of the
hole that will provide the tightness of the bearer to the stump. With practice you will be
able to hammer the pin in a rolling motion so that the pin is constantly driven down and
over the edge of the bearer tightening it to the stump.
Bouncing up and down
As strange as it might sound, if you balance on top of the bearer and bounce your body
weight onto the bearer in time with striking the hammer against the pin at the bearer,
you can add a significant amount of tension to the connection which tightens the stump
pin to the bearer.
Joining bearers
The bearers are to be skew nailed with 75 mm nails where they join. Ensure that all
bearers are supported on the stumps by a minimum of 20 mm. The skew nails are to be
inserted in each side of the bearer, but preferably not in the top of the bearer, as it may be
necessary to plane the top of the bearer and the nails would prevent this.
Fit a gang nail approximately 100 mm long × 50 mm wide across the joint of the
bearers on each side. The easiest gang nails to fit are those with the pins raised up in the
plate giving you a flat base to sit on the timber. The pins are then hammered down into
