replaced completely, rather than spliced. Bolt holes
should be carefully placed for proper alignment. When
wood braces are fastened to piling, the pile should not
be cut to obtain a flush fit. The braces should be bolted,
if possible, above the high waterline. After bolt holes
have been drilled, they should be treated with
preservative, preferably with a specially designed bolt
hole that forces the preservative into the hole under
pressure. Where decking has been removed for repairs,
it is often possible to drive brace piles to provide
lateral stiffness. This eliminates all bolt holes except
at the top of the structure immediately under the
Fire Curtain Walls
Fire curtain walls that have rotted or that have been
damaged or severely attacked by marine borers should
be restored to the original condition. When damaged
timbers are replaced, they may be spliced out. Splices
should not be made in the same location on both sides
of the wall because an open crack would remain. The
curtain wall should be as airtight as possible after
repairs are completed. Wood fire curtains are usually
made of two layers of timberthe joints in one layer
running diagonally to the joints in the other. It is
important that the joints be tight and that both sides of
the wall be completely repaired.
The decayed top of wood-bearing piles can be
repaired by cutting off the damaged portion and
building up to the proper height with sound timber (fig.
7-22). Driftpins should be driven through the cap and
Figure 7-21.Stringer splice.
Figure 7-22.Replacing top of piles.
down through the new section of pile. This involves
the removal of some of the deck planking. In every
case, fishplates of metal or treated wood should be
used to hold the new section in place. Fasten the
fishplates securely with spikes, lag screws, or bolts.
Where all the piles in a bent have decayed tops but
there is less than a foot of unsound piling, the method
shown in figure 7-23 maybe used. The top of each pile
in the bent is cut off to allow the installation of an
additional 12-inch by 12-inch cap under the existing
cap. Drive the driftpins through the caps into the piles
to hold the tops in place. In most cases, the connection
of the caps to the piles should be further strengthened
by bolting them together with 1-inch bolts and 12
1/2-inch by 3/8-inch steel straps. Use 1-inch bolts for
bolting the two caps together.
Piles that are broken or badly damaged should be
replaced (fig. 7-24). The old pile should be pulled and
a new one driven in its place. Where old piles cannot
be pulled or where they break off, the old pile must be
Figure 7-23.Repair of top of piles.