Civil Engineering Reference
In-Depth Information
The products are not a problem for the
indoor climate. The joints can usually be easi-
ly dismantled so that the materials they join
together can be re-used. Wooden pins are usu-
ally glued or swollen into the components
they bind. They can be sawn off or drilled out
for re-use of structures. Pure timber waste can
be energy recycled or composted.
Metal
Nails
There are two main groups of nails: cut nails
and wire nails. Cut nails are the oldest and
original type and usually have a slight wedge
form. They were used in all situations until the
end of the nineteenth century, when the man-
ufacture of wire nails began. Wire nails are
ubiquitous nowadays. In the UK they are
round or oblong; in Scandinavia they usually
have a square cross-section with a pyramidal
tip. Galvanized nails are used on external sur-
faces to cope with recurring dampness. They
are also used internally, galvanizing is usually
unnecessary.
Figure 17.3: Standard wood screws.
Gangnailplates
These are made for fixing larger components
together, such as the timbers within a roof
truss. The gangnailplate is a galvanized steel sheet punched to form many nails,
which makes a good fastening and prevents the timber from splitting.
Screws
Screws draw themselves into the timber as they are turned, and are used in finer
joinery work, ironmongery and internal detailing. The work is more demanding
than nailing, but screws damage the timber far less.
Bolts
Metal bolts are used in connections where strong forces are to be transferred.
Toothplate timber connectors are often laid between structural parts to increase
