MERBAU www.itimerbau.com.au
ENGINEERING SPANTABLES FOR BEAMS, RAFTERS, FLOOR BEARERS, FLOOR JOISTS AND POSTS.
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 1
but is much lighter.” 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. 1
http://www.woodsolutions.com.au/Wood-Product-Categories/Glulam - 17/12/2013
CHARACTERISTIC STRENGTHS AND ELASTIC MODULI FOR HORIZONTALLY LAMINATED GLULAM GRADES Characteristic strengths (MPa)
Elastic molduli (MPa)
Bending
Tension parallel to grain
Shear in beam
Compression parallel to grain
Fb
Ft
Fs
Fc
E
G
GL13
33
16
3.7
33
13300
900
GL17
42
21
3.7
35
16700
1110
Stress Grades
CONTENTS
Short duration average Short duration average modulus of elasticity modulus of rigidity for parallel to the grain beams
PAGE
Engineer’s structural certification
3
Verandah beam - wet use 450 roof overhang
4
Rafters - wet use
5
Floor bearers - wet use
6
Floor joists - wet use with deck
7
Roof posts - supporting roof only
8
Diagrams
9
2
STRUCTURAL CERTIFICATION
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
Ron O’Hara BE (Civil) MIPENZ David King ME (Civil) MIPENZ CPEng IntPE
3
VERANDAH BEAM Loads
Roof weight: 30kg/m² Roof overhang: 450mm Roof Snow Load: 0 kPa
Roof Live Load Snow Load
Deflection limits 0.3 kPa 0.25 kPa 1.1 kN 0.00 kPa
N3 Wind Classification
Dead Loads span/300 or 15mm Live loads span/300 or 12.5mm Wind load span/250 or 15mm
Wet Use Single Span GL17
42mm Beams 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
65mm Beams 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
4
RAFTERS Roof weight: 30kg/m² Roof Snow Load: 0 kPa
Loads Roof Live Load Snow Load
N3 Wind Classification
Deflection limits 0.03 kPa 0.25 kPa 1.1 kN 0.00 kPa
Dead Loads span/300 or 20mm Live loads span/300 or 12.5mm Wind load span/250 or 1mm
Wet Use Single Span GL17
42mm Beams 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
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*
65mm Beams Rafter Spacing
Notes 1. 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
5
FLOOR BEARERS Loads
Deflection limits
Roof Live Load
0.4 kPa 4.0 kPa 1.8 kN
Short term span/300 or 12mm Long term span/360 or 9mm 1kN 2mm
2.00kPa
Wet Use Single Span GL17
42mm Beams 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
65mm Beams 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
Notes 1. Bearers designed to provisions of AS 1720.1:1997, Timber Structures. 2. Timber grade GL17, wet use 3. 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.
6
FLOOR JOISTS Loads Roof Live Load
2.00kPa
Deflection limits 0.4 kPa 2.0 kPa 1.8 kN
Short term span/300 or 12mm Long term span/360 or 9mm 2mm for 1kN point load
Wet Use - With Ceiling Single Span GL17
42mm 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
65mm Beams
Notes 1. Joists designed to provisions of AS 1720.1:1997, Timber Structures. 2. Timber grade GL17 - wet use 3. 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.
7
POSTS N3 Wind Classification
Supporting Roof Only GL13
Roof Weight 30kg/m²
Steel Sheet (0.75) 13mm Plaster Ceiling
Tributary roof area (m2)
4
6
8
Post Size
10
12
15
20
25
30
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 Solid Veneer
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*
Roof Weight 60kg/m² Tributary roof area (m2)
4
Terra-cotta or Concrete Tiles, Battens 6
8
Post Size
10
12
15
20
25
30
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 Solid Veneer
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
8
DIAGRAMS Verandah Roof Beam
Rafters
9
DIAGRAMS Deck Bearer
Floor or Deck Bearer
10
DIAGRAMS Deck Joists
Floor or Deck with Cantilever Joist
11
DIAGRAMS Posts
12
AVAILABLE IN A WIDE RANGE OF POST, BEAM AND NON-STRUCTURAL SIZES Sizes
Grade
Finish
Available lengths
90 x 90mm
GL13
F/J Laminated
2.4, 2.7, 3.0, 3.6, 4.2, 4.8, 5.4, 6.0m
115 x 115mm
GL13
F/J Laminated
2.4, 2.7, 3.0, 3.6, 4.2, 4.8, 5.4, 6.0m
135 x 135mm
GL13
F/J Laminated
2.4, 2.7, 3.0, 3.6, 4.2, 4.8, 5.4, 6.0m
115 x 115mm
GL13
Solid Faced Veneer
2.4, 2.7, 3.0, 3.6, 4.2, 4.8, 5.4, 6.0m
140 x 140mm
GL13
Solid Faced Veneer
2.4, 2.7, 3.0, 3.6, 4.2, 4.8, 5.4, 6.0m
190 x 190mm
GL13
Solid Faced Veneer
2.4, 2.7, 3.0, 3.6, 4.2, 4.8, 5.4, 6.0m
70 x 42mm
GL17
F/J Laminated
6.0m
90 x 42mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
140 x 42mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
190 x 42mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
240 x 42mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
290 x 42mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
140 x 65mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
190 x 65mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
240 x 65mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
290 x 65mm
GL17
F/J Laminated
3.6, 4.2, 4.8, 5.4, 6.0m
18 x 18mm
F/J Quad
5.4m
30 x 11mm
F/J DAR
5.4m
30 x 18mm
F/J DAR
5.4m
620 x 30mm
F/J Laminated DAR Benchtop 4.2m
Posts
Beams
Non-Structural
Decking / Screening 70 x 19mm
F/J DAR
5.4m
90 x 19mm
F/J DAR
5.4m
Hand Rail & Bottom Rails coming soon
MERBAU www.itimerbau.com.au
For more information please contact your ITI Rep or contact your local ITI office ITI Sydney: 02 8805 5000 ITI Newcastle: 02 4953 7666 John Cook & Sons: 02 9833 0355
NSW 13
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.
