BUILDING A BOARDWALK- The Deck
A boardwalk is a structure that uses widely spaced bents or
piers as a foundation.
Stringers, parallel with the center line of the
boardwalk, rest on the ledgers of the bents or piers. The stringers support the
deck, which is usually 2 by 6 or 2 by 8 lumber laid perpendicular to the
center-line and nailed or screwed to the stringers, or to nailers bolted to the
stringers.
Boardwalks usually have a curb or handrail along their edges.
Basically, a boardwalk is a series of connected bridges,
each with a span as long as is practical, perhaps 8 to 20 feet. At most wetland
sites, longer stringers are not practical because they are difficult to
transport.At least two stringers or beams rest on the ledgers and span the
space between consecutive bents or piers. As the space between bents or piers
increases, a third stringer, or heftier stringers, must be used.
Long, thick stringers are more expensive than smaller ones.
However, they permit the bents or piers to be farther apart.
Ideally, the bottom
of the stringers of a boardwalk should be above high-water levels, but this is
often impractical. To reduce maintenance, the design of the boardwalk should
avoid interference with the flow of floodwater and floating debris.The height
of anticipated floodwater may seriously affect the design of a proposed
handrail.
Often boardwalks are found around visitor centers, heavily
used interpretive trails, or at other high-use sites. The sophisticated
construction and materials needed for a boardwalk are less appropriate in the
backcountry where the trail user expects simpler, more rustic construction and
more challenging facilities.
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