Laminated Veneer Lumber (LVL) is an engineered wood product made by bonding thin wood veneers under heat and pressure. It was developed in the 1970s and is comparable in strength to solid timber, concrete, and steel. LVL can be manufactured in large sizes and lengths and is commonly used for beams, lintels, trusses, and structural applications where sawn timber is traditionally used. It is made by gluing thin wood veneers together which are oriented with grain running lengthwise, then pressed and cured. LVL has consistent engineering properties and high strength making it suitable for long spans and structural uses.

1. LAMINATED VENEER
LUMBER

2. INTRODUCTION
• Laminated Veneer Lumber (LVL)
is a high-strength engineered
wood product used primarily for
structural applications. It is
comparable in strength to solid
timber, concrete and steel and is
manufactured by bonding
together rotary peeled or sliced
thin wood veneers under heat
and pressure.

3. HISTORY
• LVL was developed in the 1970s and
is today used for permanent structural
applications including beams, lintels,
purlins, truss chords and formwork.
LVL can be used wherever sawn
timber is used however one of the
main advantages is that it can be
manufactured to almost any length,
restricted only by transportation to
site.

4. APPLICATIONS
• Its applications include all the end
uses to which structural wood has
been traditionally used, such as,
beams, rafters, stringers, joists, posts
and framework construction, stiles,
rails and frames of doors and
windows, vehicle bodies, railways
coaches, containers, framework of
furniture cabinets, shelving, etc.

5. MANUFACTURE
• The veneers shall be reasonably smooth
to permit an even spread of glue. After
preservative treatment they shall be dried
and conditioned to moisture content not
exceeding 10 percent before bonding.
• LVL may be directly manufactured in the
nominal size of the components
ultimately desired (allowing margin for
final dressing and sanding) or in planks of
larger lengths and widths from which the
desired size of components may be
obtained by ripping.

6. • Glue shall be evenly spread over the veneers, not
leaving any unglued or glue-starved areas. The
glued veneers shall be assembled with the grain
direction in all the layers aligned longitudinally.
• No overlap of veneer ends or edges shall be
permitted during assembly. The requisite number of
veneer layers may' be assembled to obtain the
required finish. The assembly shall be hot pressed
under controlled conditions of temperature,
pressure and pressing time which depends upon the
thickness of the composite.
• The stack under press shall then be cooled down to
near room temperature by suitable cooling
schedule in order to stabilize it.
• The pressed components or blanks, if required to be
stored, shall be stacked flat with sufficient load on
its top. Blanks may be ripped and cross cut to the
required sizes.

7. PRESERVATIVES & SIZES
PRESERVATIVES:
• Veneers used for LVL shall be given
suitable preservative treatment before
lamination, with preservative that is
compatible with the adhesive to be used.
• Only fixed type of water soluble
preservatives, CCA or CCB, or non-
leachable, solvent soluble preservatives
as per IS 401 shall be used for treating the
veneers.
• Retentions of preservatives shall be as
per IS 401 depending upon the proposed
end use.
SIZES:
• LVL sizes will vary between
manufacturers. Manufactured sheets
or billets are usually 1200 mm and
2400 mm wide and in standard
thicknesses of 35, 36, 39, 45 and 63
mm.
• Lengths of up to 12 m are available
from some manufacturers.
• Beam depths are available of 1200
mm deep.

8. PROPERTIES:
FIRE RESISTANCE
Fire resistance of LVL and LSL depends on the
section size of the member.
LVL and LSL acts similarly to solid timber during
exposure to fire, and has a slow and predictable
charring rate, dependent on the timber species.
When members are required to have a fire
resistance rating, this can be calculated by
subtracting a charred thickness from the original
member size.
Higher stresses can be used in combination with
the reduced cross section.
TECHNICAL
SPECIFICATIONS:

9. ENGINEERING CONSIDERATIONS:
Engineering characteristics
The properties of LVL show much less variation than
those of both sawn timber and glulam. In fact, LVL
has a coefficient of variation in structural properties
that is similar to hot rolled steel sections.
Like other timbers, LVL offers good chemical
resistance. It is resistant to most acids, rust and
other corrosive agents. If exposed to strong
oxidising agents, sulphides and alkalis, ‘pulping'
action (timber becomes very fibrous) may occur, so
specialist advice should be sought regarding the
choice of timber species and adhesive for specific
applications.
WORKMANSHIP:

10. ENGG. CONSIDERATIONS CONT….
• LVL beams
• The veneers that make up LVL are oriented in the same direction, which makes it an excellent material for beams, with
spanning in one direction. Due to the long length, large depth and reliable strength with uniform stiffness that LVL offers, it
is very effective for carrying loads over long spans.
• LVL beams are normally straight, as the most cost-effective production is to cut a number of straight members out of one
sheet; curved or tapered members can also be cut out of a single sheet although this will likely be more expensive. Care
with sloping grain is needed in determining performance with curved or tapered members.
• LVL can be used as primary roof members such as strutting beams, hanging beams, valley or hip rafters and ridge
beams. It can also be used for long span joists and floor bearers.
• When combined with stiff connections at the knee and ridge, LVL can be used in portal frames.
• LVL sections can be quite slender (a high depth to breadth ratio), so care should be made to provide torsional stability to
the member at its supports.
• This can be achieved with blocking pieces between members or a strap over the top of the beam. Deep members may
need fly bracing to prevent lateral torsional buckling of beams under wind uplift loading.
• Where large shear forces need to be carried (particularly in the connections), then it may be necessary to use cross-
banded LVL.

11. TRUSS MEMBERS:
• LVL has high tensile strength relative to
sawn timber and high reliability. This
makes it ideal for use in trusses.
• Truss members can be made from single
pieces of LVL, but for very large loads, LVL
can be glue-laminated to make large
cross-section square or nearly square
members. In all truss applications, the
limiting factor is the connection, so for
very large loads, complex high capacity
connections will be required. This may
require testing of prototypes of the joints
to verify the capacity.

12. JOINTS AND CONNECTORS:
• Joining LVL are the same as joining solid timber. Traditional fasteners such as nails, screws
and bolts can be used as well as proprietary metal connectors such as framing anchors,
joist hangers etc.
• Concealed or exposed plates can also be used to secure butt connections such as in portal
knee joints and joins in curved members.
• At supports it is essential that minimum bearing requirements be achieved. This may vary
between different manufacturers.