Product FAQ's

Frequently asked questions about our LVL products.

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How is Wesbeam LVL different in its performance to sawn timber and steel?

Wesbeam LVL is manufactured from 4.8mm veneers of plantation timber that are rotary peeled, dried and glued under heat and pressure to form a solid member. The veneers are randomly distributed throughout the beams during manufacture thereby reducing the effect of natural features like knots and gum veins.

The properties of LVL show much less variation than those of sawn timber. In fact, LVL beams are on average 50% stiffer, 2 to 3 times stronger and have more density than the sawn timber from which they’re manufactured.

Steel - being a manufactured product - has higher strength and stiffness properties compared to LVL but it is also almost 12 times heavier. This means that much of its higher strength properties are used to support the steel beam itself.

How much does LVL deflect over time and is LVL more likely to lead to cornice cracking than steel beams?

All beams, regardless of product material (e.g. LVL, steel), deflect upon installation. This is caused by the self-weight of the beam as well as the loads it supports. But when using the relevant Australian Standards and the Wesbeam span tables, the beams will perform as specified and achieve the same deflection performance as steel over time.

What is coefficient of variation (CoV) and how is it relevant to the specification of structural beams?

Coefficient of variation (CoV) is a measure of the average variability of stiffness in a load-bearing element such as LVL, timber and steel. Structural products with a low CoV behave more closely to the design with predicted behaviour whereas products with higher CoVs tend to vary to a higher degree to their predicted behaviour. 

Universal steel beams have similar CoVs to LVL, whilst the CoV of MGP pine is at least twice that of LVL. Choosing products with a low CoV, such as LVL, will give you a more reliable job.

Because LVL is a wood-based product does that mean that it is less consistent in its performance than steel?

LVL has reliable and consistent structural properties; and has strength and stiffness capabilities greater than the individual veneers from which it is manufactured.

The maximum effect of a single natural feature (e.g. a knot) in an LVL laminate is very small as the laminates are thin compared with the thickness of the whole beam. The structural performance of LVL is reliable and consistent to its specified properties. In fact, LVL has a coefficient of variation that is similar to Australian produced hot rolled steel sections.

Wesbeam’s products and technical literature are fully compliant with relevant Australian Standards, what does that mean?

Wesbeam LVL products are manufactured in accordance with the requirements of AS/NZS 4357 Structural Laminated Veneer Lumber. Preservative-treated Wesbeam LVL is manufactured in accordance with the requirements of Codemark for e2S and AS/NZS 1604.4 (specification for preservative treatment) for Wesbeam H2 and H3.

Wesbeam’s products are commonly used in residential construction and the supporting technical literature produced is in line with the requirements of AS1684 Residential Timber Framed Construction. Wesbeam’s products are also used in commercial construction and can be readily designed and specified by building professionals.

What assumptions are made in Wesbeam’s span tables and technical literature?

Span tables and technical literature produced by Wesbeam for the residential market use the design assumptions contained in AS1720.3: 2016 – Timber structures Part 3: Design criteria for timber-framed residential buildings.

If there are any other design assumptions used or required to comply with building practices, these will be clearly stated.

How can I be sure that Wesbeam products will perform as specified in the Wesbeam literature?

Wesbeam LVL products are manufactured in accordance with the requirements of AS/NZS4357 Structural Laminated Veneer Lumber with the quality of manufacture externally checked via audits undertaken by the Engineered Wood Products Association of Australasia.

LVL Terminology

Span

The clear distance between supports measured along the beam. 

 

Continuous Span Beams

Continuous span values given in the tables should only be used where:-

a) The beam is not notched or partially cut through at internal support points and,

b) If the spans are not equal, the largest span is not greater that twice the smallest adjacent span.

However if either of the above conditions are not met, use the single span tables for the largest span to obtain the appropriate size. 

 

Overhang Span (sometimes referred to as cantilever)

The distance from the face of the support to the free end of the beam, measured along the beam.

 

Spacing

Tables such as those for rafters, floor joists and ceiling joists require the spacing of members to be known or selected so you can obtain the required size for a given span. Spacing should be interpreted as the centre to centre distance between adjacent parallel members.

 

Roof Load Width

Roof Load Width (RLW) is used in these tables to determine the load applied to isolated roof beams such as strutting beams etc. Roof Load Widths (RLW) are measures of the load applied from roofs. RLW should be determined in accordance with AS1684 Residential Timber Framed Construction.

 

Ceiling Load Width

Ceiling Load Width (CLW) determines the load applied to single roof beams such as hanging beams, strutting-hanging beams etc. CLW are measures of the load applied from ceilings. CLW should be determined in accordance with AS1684 Residential Timber Framed Construction.

 

Roof Mass

Roof mass has been separated into two categories related to the type of roof cladding — sheet and tile roof only. The roof masses are set forth in AS1720.3:2016 – Timber structures Part 3: Design criteria for timber-framed residential buildings.

 

Mid-rise

Mid-rise timber buildings are typically 4 to 8 storeys high. Have an effective height of not more than 25 metres.

 

Mass Timber

An element not less than 75 mm thick as measured in each direction formed from chemically-bonded laminated timber and includes

  • Cross laminated timber (CLT)
  • Laminated veneer lumber (LVL)
  • Glued laminated timber (Glulam)