MERBAUwww.itimerbau.com.au

ENGINEERING SPANTABLES FOR BEAMS, RAFTERS, FLOOR BEARERS, FLOOR JOISTS AND POSTS.

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CONTENTS PAGE

Engineer’s structural certification

Verandah beam - wet use 450 roof overhang

Rafters - wet use

Floor bearers - wet use

Floor joists - wet use with deck

Roof posts - supporting roof only

Diagrams

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MERBAU IS A NATURAL PRODUCT & ONE OF THE TOUGHEST BUILDING MATERIALS AVAILABLE

Merbau like all timbers will react to climatic changes during its service life. We attempt to minimise the

effect these changes may have on the appearance of the product but resin bleed, raised grain or uneven

swelling may occur as a result of climatic conditions.

To reduce the risks we recommend the use of protective finishes to enhance the appearance and

improve the service life of the product. Protective finishes will prolong the service life of finger jointed and

laminated Merbau by limiting the effects UV light has on the product, reducing moisture ingress and aiding

with the dimensional stability of the product.

ITI Merbau features “Increased strength due to the laminating process - glulam is stronger than solid

timber as it has fewer natural defects and a wider distribution. It is also comparable to steel in strength

but is much lighter.”1 The glue used in the laminating process is Phenol Rescorcinol Formaldehyde

and is considered the industry standard for structural engineered wood applications. A high degree of

dimensional stability is also provided as glulam Merbau is manufactured from seasoned timber and is

therefore less prone to movement caused by changes in moisture content.

StressGrades

Characteristic strengths (MPa) Elastic molduli (MPa)

Bending Tension parallel to

grain

Shear in beam

Compression parallel to grain

Short duration average modulus of elasticity parallel to the grain

Short duration average modulus of rigidity for

beams

Fb Ft Fs Fc E G

GL13 33 16 3.7 33 13300 900

GL17 42 21 3.7 35 16700 1110

CHARACTERISTIC STRENGTHS AND ELASTIC MODULI FOR HORIZONTALLY LAMINATED GLULAM GRADES

1 http://www.woodsolutions.com.au/Wood-Product-Categories/Glulam - 17/12/2013

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STRUCTURAL CERTIFICATION

Ron O’Hara BE (Civil) MIPENZDavid King ME (Civil) MIPENZ CPEng IntPE

STRUCTURAL CERTIFICATION

SPAN TABLES FOR ITI Merbau range of products

Incorporating span tables for:

GL17 Floor and deck bearers and joists, GL17 rafters, ridge beams and verandah beams.

GL13 posts. I, David J King, being a Chartered Professional Engineer and currently holding an Annual Practising Certificate, certify that the span tables have been prepared using widely accepted engineering principles. Design loads and deflection criteria have been determined from AS/NZS 1170.0:2002, AS/NZS 1170.1:2002 Structural Design Actions and AS4055-2006 Wind loads for housing. Structural design is to the requirements of AS1720.1:2010 Timber Structures.

David King ME (civil) MIPENZ CPEng (no. 145511) New Zealand IntPE (NZ) 12 September 2013

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VERANDAH BEAM

Roof weight: 30kg/m²Roof overhang: 450mmRoof Snow Load: 0 kPa

N3 Wind Classification Wet Use Single Span GL17

42mm Beams

65mm Beams

LoadsRoof 0.3 kPaLive Load 0.25 kPa 1.1 kNSnow Load 0.00 kPa

Deflection limits

Dead Loads span/300 or 15mmLive loads span/300 or 12.5mmWind load span/250 or 15mm

Verandah Width

1200 1800 2400 3000 3600 4200 4800 5400 6000

140 x 42 3200 2950 2800 2650 2500 2350 2250 2150 2050

190 x 42 4150 3950 3750 3600 3350 3150 3000 2850 2700

240 x 42 4950 4700 4500 4150 3850 3650 3450 3250 3150

290 x 42 5750 5350 4850 4500 4200 3900 3700 3550 3350

Verandah Width

1200 1800 2400 3000 3600 4200 4800 5400 6000

140 x 65 3000 2700 2450 2300 2150 2000 1900 1800 1750

190 x 65 3000 2700 2450 2300 2150 2000 1900 1800 1750

240 x 65 5000 4750 4500 4350 4050 3850 3650 3450 3300

290 x 65 5350 5050 4850 4650 4400 4150 3950 3750 3600

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RAFTERS

Roof weight: 30kg/m²Roof Snow Load: 0 kPa

N3 Wind Classification Wet Use Single Span GL17

42mm Beams

65mm Beams

LoadsRoof 0.03 kPaLive Load 0.25 kPa 1.1 kNSnow Load 0.00 kPa

Deflection limits

Dead Loads span/300 or 20mmLive loads span/300 or 12.5mmWind load span/250 or 1mm

Rafter Spacing 600 760 900 1000 1200

70 x 42 1900 1800 1700 1650 1550

90 x 42 2500 2350 2200 2150 2000

140 x 42 3950 3650 3450 3300 3100

190 x 42 5100 4850 4650 4500 4250

240 x 42 6000* 5750 5500 5350 5150

290 x 42 6000* 6000* 6000* 6000* 5800

Rafter Spacing 600 760 900 1000 1200

140 x 65 4550 4200 4000 3850 3600

190 x 65 5700 5400 5150 5050 4800

240 x 65 6000* 6000* 6000* 6000 6000*

290 x 65 6000* 6000* 6000* 6000* 6000*

Notes1. Wind loads have been derived from AS 4055-1992, Wind loads for housing, with the net pressure coefficients (Cpn)of -1.5 and +0.7 for N winds and -2.5 and +1.05 for C winds.2. Stress grade of timber is GL17.3. Design to provisions of AS 1720.1:1997, Timber Structures.4. Spans may be increased by 10% for rafters continuous over 2 or more spans.5. Maximum 450mm overhang.

* Longest length ITI Merbau beam available is 6.0m

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FLOOR BEARERS

2.00kPa Wet Use Single Span GL17

42mm Beams

65mm Beams

LoadsRoof 0.4 kPaLive Load 4.0 kPa 1.8 kN

Deflection limits

Short term span/300 or 12mmLong term span/360 or 9mm 1kN 2mm

Verandah Width / Joist Span

1200 1800 2400 3000 3600 4200 4800 5400 6000

140 x 42 2150 1900 1650 1500 1350 1250 1200 1100 1050

190 x 42 2950 2600 2250 2050 1850 1700 1600 1500 1450

240 x 42 3550 3250 2850 2550 2350 2200 2050 1950 1850

290 x 42 4100 3800 3450 3100 2850 2650 2450 2350 2200

Verandah Width / Joist Span

1200 1800 2400 3000 3600 4200 4800 5400 6000

140 x 65 2500 2250 2050 1850 1700 1600 1450 1400 1300

190 x 65 3350 3000 2800 2550 2300 2150 2000 1900 1800

240 x 65 3950 3650 3450 3200 2900 2700 2550 2400 2300

290 x 65 4550 4200 3950 3750 3550 3300 3050 2900 2750

Notes1. Bearers designed to provisions of AS 1720.1:1997, Timber Structures.2. Timber grade GL17, wet use3. Bearers do not support roof loads.4. Allowance of 0.3kN/m added for balustrade.5. Spans may be increased by 10% for bearers continuous over 2 or more spans.

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FLOOR JOISTS

2.00kPa Wet Use - With Ceiling Single Span GL17

LoadsRoof 0.4 kPaLive Load 2.0 kPa 1.8 kN

Deflection limits

Short term span/300 or 12mmLong term span/360 or 9mm2mm for 1kN point load

42mm Beams

65mm Beams

Joist Size 400 450 600

70 x 42 1350 1300 1200

90 x 42 1750 1700 1550

140 x 42 2850 2750 2550

190 x 42 4000 3850 3550

240 x 42 4750 4600 4350

290 x 42 5450 5300 4950

Joist Size 400 450 600

140 x 65 3450 3300 3000

190 x 65 4400 4300 4050

240 x 65 5200 5050 4750

290 x 65 5950 5800 5450

Notes1. Joists designed to provisions of AS 1720.1:1997, Timber Structures.2. Timber grade GL17 - wet use3. Spans may be increased by 10% for joists continuous over 2 or more spans.4. Solid blocking required at midspan and at ends for joists with a span of 2.5m or greater.

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POSTS

N3 Wind Classification Supporting Roof Only GL13

Roof Weight 30kg/m² Steel Sheet (0.75) 13mm Plaster Ceiling

Terra-cotta or Concrete Tiles, BattensRoof Weight 60kg/m²

Tributary roof area (m2)

4 6 8 10 12 15 20 25 30

Post Size Maximum Post Height (m)

90 x 90 F/J Lam 4.50 4.50 4.30 3.70 3.30 2.80 2.10

115 x 115 F/J Lam & Solid Veneer

5.75 5.75 5.75 5.75 5.70 5.00 4.10 3.50

135 x 135 F/J Lam

6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 6.00 5.20 4.50

140 x 140 SolidVeneer

6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 5.60 5.00

190 x 190 Solid Veneer

6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 6.00*

Tributary roof area (m2)

4 6 8 10 12 15 20 25 30

Post Size Maximum Post Height (m)

90 x 90 F/J Lam 4.50 4.40 3.70 3.20 2.70 2.30 1.60 0.90

115 x 115 F/J Lam & Solid Veneer

5.75 5.75 5.75 5.60 5.00 4.30 3.50 2.80

135 x 135 F/J Lam

6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 5.20 4.40 3.80

140 x 140 SolidVeneer

6.00* 6.00* 6.00* 6.00* 6.00* 5.60 4.80 4.20

190 x 190 Solid Veneer

6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 6.00* 6.00*

* Longest length ITI Merbau beam available is 6.0m

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DIAGRAMS

Verandah Roof Beam

Rafters

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DIAGRAMS

Deck Bearer

Floor or Deck Bearer

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DIAGRAMS

Deck Joists

Floor or Deck with Cantilever Joist

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DIAGRAMS

Posts

Copyright reserved. 2013 ITI Australia.Every effort has been made to ensure the information contained in this booklet complies with the Building Code at the date of publication. No responsibility is accepted for any errors or omissions in this booklet or for any work or specification based on this information.

MERBAUwww.itimerbau.com.au S

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Sizes Grade Finish Available lengths

AVAILABLE IN A WIDE RANGE OF POST, BEAM AND NON-STRUCTURAL SIZES

90 x 90mm GL13 F/J Laminated 2.4, 2.7, 3.0, 3.6, 4.8, 5.4, 6.0m

115 x 115mm GL13 F/J Laminated 2.4, 2.7, 3.0, 3.6, 4.8, 5.4, 6.0m

140 x 140mm GL13 F/J Laminated 2.4, 2.7, 3.0, 3.6, 4.8, 5.4, 6.0m

190 x 190mm GL13 F/J Laminated 2.4, 2.7, 3.0, 3.6, 4.8, 5.4, 6.0m

POSTS

190 x 30mm GL17 F/J Laminated 6.0m

70 x 42mm GL17 F/J Laminated 5.4, 6.0m

90 x 42mm GL17 F/J Laminated 3.6, 4.8, 5.4, 6.0, 7.2m

140 x 42mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

190 x 42mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

240 x 42mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

290 x 42mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

140 x 65mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

190 x 65mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

240 x 65mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

290 x 65mm GL17 F/J Laminated 3.6, 4.8, 6.0, 7.2m

66 x 18mm F/J DAR 5.4m

42 x 30mm F/J DAR 5.4m

42 x 10mm F/J Cover Strip 5.4m

18 x 18mm F/J Quad 5.4m

30 x 30mm F/J Scotia 5.4m

BEAMS

Non-Structural

For more information please contact your ITI Rep or contact your local ITI office

ITI SA: 08 8347 7011

90 x 19mm F/J DAR 5.7m

Decking