Building Construction Handbook, Eighth Edition

Vertical Laminations ~ not

often used for structural

laminated timber members

and is unsatisfactory

for curved members.

Horizontal Laminations ~ most popular method for all types of

laminated timber members. The stress diagrams below show that

laminates near the upper edge are subject to a compressive stress

whilst those near the lower edge to a tensile stress and those near

the neutral axis are subject to shear stress.

Flat sawn timber shrinks twice as much as quarter sawn timber

therefore flat and quarter sawn timbers should not be mixed in the

same member since the different shrinkage rates will cause

unacceptable stresses to occur on the glue lines.

Planing ~ before gluing, laminates should be planed so that the

depth of the planer cutter marks are not greater than 0„025 mm.

Laminated Timber