Laminated Timber ~ sometimes called `Gluelam' and is the process
of building up beams, ribs, arches, portal frames and other
structural units by gluing together layers of timber boards so that
the direction of the grain of each board runs parallel with the
longitudinal axis of the member being fabricated.
Laminates ~ these are the layers of board and may be jointed in
width and length.
Joints ~
Width † joints in consecutive layers should lap twice the board
thickness or one quarter of its width whichever is the greater.
Length † scarf and finger joints can be used. Scarf joints should
have a minimum slope of 1 in 12 but this can be steeper (say 1 in 6)
in the compression edge of a beam:-
Moisture Content ~ timber should have a moisture content equal
to that which the member will reach in service and this is known as
its equilibrium moisture content; for most buildings this will be
between 11 and 15%. Generally at the time of gluing timber should
not exceed 15–3% in moisture content.
Laminated Timber