1. LVL Floor Panel Systems
Massive Timber Seminar
18th June – Sydney
19th June – Melbourne
Authored and presented by Andy Van Houtte

2. LVL Flooring Panel Characteristics
Design Solutions
• Light weight structures
• Flexible designs
• Multiple geometries
• Acoustic solutions
• Fire rating solutions
• Composite action
Construction Advantages
• Speed of installation (less overall workers on site)
• Smaller cranes or larger reach (multiple lifts)
• Smaller supporting structures (1/5th the mass of concrete)
• Less truck movements
• Smaller/less expensive foundations
• Cleaner work environment – dry site
• Quieter work site
• Easier to install services
• Instant working platform

3. Panel options
1. T-beam
• bottom flange
2. Cassette
• Bottom flange fire rated
3. Concrete top
• Partial composite action
4. Hanging ceiling
• fire performance/acoustical
Top Skin Sizes
Xband LVL 17, 21, 25, 36, 45mm
LVL Joists
Thicknesses 35, 45, 63, 90mm
Widths 150, 200, 240, 300, 360, 400, 460, 600mm
Length up to 18m

4. T-Panels
1. Simple to fabricate
2. Cost effective – glue and nail/screw
3. Fast to install
4. Full composite action with floor sheathing
can be achieved with long length xband LVL
5. Residential and commercial applications

5. Cassette Floors
1. More expensive than T-beam to fabricate
2. Not a total solution
3. Dynamics can govern due to light weight
1. Good span to weight ratio
2. Bottom flange can act as sacrificial fire
barrier
3. Between joists can support services and
insulation.
4. Can be used for hit and miss flooring
effectively.

6. Concrete topping
Advantages
• Thermal mass
• Rigid diaphragm action
• Dynamic damping
• Acoustical absorption
• Partial composite action possible
• Potential for pre fabrication
Disadvantages
• J2 factor 3-4 (composite action only)
• lots of mechanical fasteners/notches for composite action
• Concrete shrinkage
• Wet trade on site
2 2
( )ef c c t t c c c c t t t tEI E I E I E A a E Aa    

7. Cost versus Span
Span (m)
$/m2
100
120
140
160
180
200
220
240
4 5 6 7 8 9 10 11
Cassette FRR60
T Beam
T Beam FRR60
Design loadings:
3kPa live load
2kPa superimposed dead load
No concrete composite action
considered
Concrete cost not included

8. Panel Design
Strength
1. Bending strength limited by concrete capacity
2. Bending strength limited by timber capacity
3. Shear strength
4. Shear Connector Capacity
Deflection
Dynamics
Traditionally fundamental frequency greater than 8Hz was employed to provide a guideline for the measure of a suitable floor response.
This was simplified in AS1684 – residential framing (based on research by Mackenzie and Juniper, 1997) to a maximum deflection of 2mm
under a 1kN point load (in conjunction with the load distribution factor) for timber joists.
More recently a more relevant method of measuring dynamic acceptability is by the floor acceleration (RMS), with different response
criteria given the intended purpose of the floor. A good resource is the UK Concrete Society CCIP-016 report – Design Guide for footfall
induced vibration of structures or alternatively using the rigorous analysis (SCI P-354)

9. Spreadsheet design – makes it easy
Stress Skin Panels
Joist spacing 600 mm
MoE of system 11 GPa
Total thickness 720
Laminate count 12
Geometrical centroid of section 420.62
Structural centroid of section (Stiffness) 445.47
2nd moment of Inertia (Geometrical) 0.00019
2nd moment of Inertia (Structural) 0.00019
Note: Cross ply contributes 0.3E
Top Flange Web Bottom Flange
Laminate Depth (mm) Width (mm) Contribution for I
Contribution for
Z E (GPa) F'b (Mpa) Depth (mm)Width (mm) Contribution for I Contribution for Z E (GPa) F'b (Mpa) Depth (mm) Width (mm)
1 3.5 400 1 1 9 35
2 3.5 400 1 1 9 35
3 3.5 400 0.3 0 9 35
4 3.5 400 1 1 9 35
5 3.5 400 1 1 9 35
6 3.5 400 1 1 9 35
7 3.5 400 1 1 9 35
8 3.5 400 0.3 0 9 35
9 3.5 400 1 1 9 35
10 3.5 400 1 1 9 35
11 610 45 1 1 11 38
13 75 400
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)( Siii zzEA -LVL Floor joists (mm) kg/m2
Supporting floor loads only, also not including deck joists Bearer width 75 Floor Dead Load 40
E value 10700000000 f's 6000000 loads
f'b 42000000 f'p 12000000 DL DL LL LL LL LL LL LL LL
Joist spacing G1 G2 Q1 Q2 Q3 Q4 Q5 Q6 Q7
Member B D I Z Reference Estimated length (mm) (kN/m) (kN) (kN/m) (kN/m) (kN/m) (kN/m) (kN) (kN) (kN)
400x45 45 400 240000000 1200000 16 4.5 400 0.257 0.000 0.200 1.600 0.300 1.200 2.22 6.00 0.65
400x45 45 400 240000000 1200000 16 4.5 450 0.277 0.000 0.225 1.800 0.338 1.350 2.20 6.75 0.64
400x45 45 400 240000000 1200000 16 4.5 600 0.337 0.000 0.300 2.400 0.450 1.800 2.41 9.00 0.75
Bending Deflection Shear Bearing
1 2 3 hb hc g42 g41
300 0.20 0.05 0.24 0.17 0.15 0.52 28.18 120.9 0.82 0.65
450 0.22 0.06 0.27 0.17 0.17 0.59 28.18 131.4 0.82 0.64
600 0.29 0.07 0.36 0.20 0.22 0.78 28.18 55.4 0.89 0.75
Bending Deflection Shear Bearing All
300 OK OK OK OK TRUE
450 OK OK OK OK TRUE
600 OK OK OK OK TRUE

10. Acoustics and Fire Performance
Fire Resistance Ratings requires typically 60, 90 or
120mins in Australia,
Options:
1. Can be achieved with a fire rated plasterboard ceiling
2. Can be achieved with LVL char rating of 0.7mm/min
Acoustics – impact and airborne transmission
1. Best performance achieved with an acoustical
break – like a hanging ceiling
2. Floor toppings
3. Sound insulation internally between joists

11. Reference Material
1. Potius Panels - www.potius.co.nz
2. STIC EXPAN Material (UTS) – Keith Crews, Rijun Shrestha, Christophe Gerber
3. A dynamic approach for timber floor design - Chui and Smith
4. Composite Concrete slab and LVL floor systems – Fragiacomo and Deam
5. Eurocode 5
6. Timber Designers Manual - Ozelton and Baird
7. Springiness and Human induced floor vibrations – Ohlsson
8. Timber Design Guide – Buchanan
9. Mackenzie and Juniper – timber framed housing – methodology and performance
criteria

12. Thank you