RoofDek D159 – Specialist Long-Span Structural Roof Deck
The RoofDek D159 is a premium deep structural deck engineered for demanding applications where exceptional long-span capability and load performance are essential. With spans up to 9.00m in solid form, the D159 is the solution for distribution centres, aircraft hangars, industrial sheds, exhibition halls, and major sports venues that demand uncompromising structural integrity.
Product Depth:
159mm | Cover Width: 750mm | Pitch: 250mm
Typical Applications
Large Distribution Centres
Solid D159 spans support sprawling warehouse layouts with minimal intermediate supports, reducing column interference and maximising usable floor space.
Aircraft Hangars
The exceptional depth and strength allow clear-span roof structures where aircraft require unobstructed ceiling heights and wide-open interiors.
Concert Halls & Exhibition Centres
The web perforated variant (pattern 3327) delivers acoustic performance for large public venues while achieving extreme structural spans.
Major Sports Arenas
D159 solid and perforated options span large spectator seating areas while controlling acoustic reflections in the perforated variant.
Why This System Is Used
Exceptional Span Capability
- Solid D159 spans up to 9.00m – the longest span in the core RoofDek range
- Perforated variant spans up to 8.00m whilst maintaining acoustic benefits
- Reduces intermediate column requirements, freeing internal floor space
Material Flexibility for Demanding Sites
- 1.25mm Steel S320 for maximum rigidity in severe load conditions
- 1.50mm Aluminium Rp0.2 165 (thickest aluminium in the RoofDek range) – less than half the weight of steel
- Aluminium option reduces self-weight on long spans, lowering support structure costs
Acoustic Control Options
- Web perforated pattern 3327 (27%) – same as D137 – controls reverberation in large public spaces
- 7.6% open area on exposed soffit (14.2% of cover area) balances acoustic performance with structural integrity
- Suitable for concert halls, exhibition centres, and sports venues
Deep Profile Design
- 159mm depth is one of the deepest profiles before the D200
- Extreme moment of inertia supports long-span loads with minimal deflection
- Professional appearance for exposed ceilings in major venues
Key Technical Features
Profile Dimensions
Depth 159mm • Cover width 750mm • Trough 38mm • Narrow flange 108mm • Pitch 250mm • Bearing 100mm
Deflection Limits
Imposed load: Span/200 • Suction load: Span/150 • Industry-leading stiffness-to-weight ratio
Aluminium Advantage
1.50mm Aluminium weighs only 7.97 kg/m² vs 19.19 kg/m² for steel – moment of inertia 846.31 cm⁴/m (higher than steel) due to thicker gauge
Limited Material Options
Only 1.25mm S320 steel and 1.50mm Aluminium Rp0.2 165 – reflects the specialist structural demands that thinner gauges cannot meet
D159 Solid – Section Properties
| Material | Mass (kg/m²) | I (cm⁴/m) | Z (cm³/m) | My (Nm/m) | Iy (cm⁴/m) | Zy (cm³/m) | J (cm⁴/m) | Cw (cm⁶/m) |
|---|---|---|---|---|---|---|---|---|
| 1.25mm Steel S320 | 1.21 | 19.19 | 30.14 | 749.55 | 22.37 | 749.55 | 82.62 | 20.97 |
| 1.50mm Alu Rp0.2 165* | 1.50 | 7.97 | 15.49 | 846.31 | 13.66 | 859.19 | 46.52 | 12.16 |
Properties based on 100mm bearing. *Aluminium Rp0.2 165 grade. Solid spans: 6.00m to 9.00m.
D159 Web Perforated – Section Properties
Pattern 3327 (27%) • 3.3mm ø holes at 6.0mm triangular centres • Open area: 7.6% of exposed soffit (14.2% of cover area)
| Material | Mass (kg/m²) | I (cm⁴/m) | Z (cm³/m) | My (Nm/m) | Iy (cm⁴/m) | Zy (cm³/m) | J (cm⁴/m) | Cw (cm⁶/m) |
|---|---|---|---|---|---|---|---|---|
| 1.25mm Steel S320 | 1.21 | 17.80 | 29.34 | 738.35 | 20.53 | 738.35 | 57.59 | 14.25 |
| 1.50mm Alu Rp0.2 165* | 1.50 | 7.40 | 15.18 | 832.88 | 12.84 | 837.75 | 32.63 | 8.31 |
Web perforated — pattern 3327 (27%). *Aluminium Rp0.2 165 grade. Perforated spans: 5.00m to 8.00m.
Design & Specification Considerations
Material Selection
- 1.25mm Steel S320: Specify when maximum rigidity and load capacity are the priority. Superior bending stiffness for heavily loaded applications.
- 1.50mm Aluminium Rp0.2 165: The thickest aluminium in the RoofDek range. Specify to reduce self-weight on long spans – weight savings directly lower steel frame costs.
- No intermediate gauges available – D159 is engineered for extreme spans; thinner gauges cannot meet the structural demands.
Acoustic Performance
- Solid variant: Use for industrial applications, distribution centres, and hangars where acoustic control is not required.
- Web perforated (pattern 3327): Specify for concert halls, exhibition centres, and sports arenas needing reverberation control at extreme spans.
- VCL must be positioned underneath perforated trays when the soffit is exposed to internal spaces.
Bearing & Support
- Minimum 100mm bearing on primary beams or load-bearing walls.
- Wide bearing requirement reflects the extreme loads and spans – verify support widths at design stage.
- End restraint essential for long-span applications to control lateral-torsional buckling.
Deflection Control
- Imposed load: Span/200 – typical for internal floor/ceiling loads.
- Suction load: Span/150 – stricter limit reflects the sensitivity of long spans to wind uplift.
- Verify actual deflections against roof membrane tolerances and architectural requirements.
Installation Considerations
- Handling Long-Span Sheets: The 159mm depth and extreme spans make D159 sheets heavy and stiff. Confirm site lifting and installation equipment capacity. Use specialist lifting gear and spreader bars – do not force installation on short-span supports.
- Lateral Stability During Installation: Long spans are susceptible to lateral buckling during erection. Use temporary bracing or purlins to stabilise the deck until permanent connections are complete and loads are applied.
- Perforated Variant Installation: Pattern 3327 holes must not be bridged or sealed unless design-specific. Ensure installation teams understand the acoustic and load-distribution implications of the perforation pattern.
- VCL & Moisture Control: For perforated applications, ensure VCL is correctly positioned underneath the tray. Verify waterproofing and vapour control sequences with the design team before installation begins.
- Connection Design: Because D159 is used at extreme spans, connection design is critical. All fastening points must be sized for the full load path. Do not use undersized or standard fixings.
- QA & Inspection: Inspect for flatness and dimensional accuracy after installation. The deep profile’s stiffness means minor deviations can propagate across the span.
Common Problems Solved by D159
Excessive Intermediate Columns
Spans up to 9.00m eliminate the need for intermediate supports across wide floor plates – maximising usable space in distribution centres and hangars.
High Self-Weight on Existing Structures
Aluminium D159 (7.97 kg/m²) cuts weight nearly in half compared to steel. Lower self-weight reduces demand on primary frame and foundations.
Reverberation & Noise in Large Venues
Web perforated pattern 3327 controls acoustic reflections in concert halls, exhibition centres, and sports arenas at spans conventional profiles cannot reach.
Deflection & Vibration on Long Spans
159mm depth and superior moment of inertia (up to 846.31 cm⁴/m) control deflection and vibration on extreme-span applications.
RMD Profiles Services for D159
Supply Only
RoofDek D159 delivered to site, ready for installation. You manage design, fastening, and site work.
Supply & Design Service
RMD engineers design the roof deck system for your building, verify structural adequacy, and supply material. You manage installation and site coordination.
Supply & Fix Service
RMD supplies and installs the complete D159 roof deck system. We manage fastening schedules, alignment, and on-site quality assurance.
Safety Netting & Containment
Temporary netting and edge protection systems meet site safety requirements during deck installation and construction phases
Related Topics
RoofDek D159 • Long-span structural deck • Deep metal decking • Acoustic roof deck • Aluminium roof deck • Extra-span roofing • Industrial building systems • Distribution centre roofing • Aircraft hangar decking • Large venue acoustics • Web perforated decking
Frequently Asked Questions
What span can D159 achieve?
Solid D159 spans up to 9.00m – the longest span in the core RoofDek range. Perforated variant spans up to 8.00m. Actual spans depend on load, material choice, and deflection limits. Contact us for span tables specific to your load case.
Why is D159 only available in two material options?
D159 is engineered for extreme spans where structural performance is non-negotiable. Only 1.25mm Steel S320 and 1.50mm Aluminium Rp0.2 165 possess the bending stiffness, moment of inertia, and load capacity required. Thinner gauges cannot achieve the deflection limits or buckling resistance demanded by long-span applications.
When should aluminium D159 be specified?
Aluminium D159 (1.50mm Rp0.2 165) weighs only 7.97 kg/m² – less than half steel’s 19.19 kg/m². Specify aluminium when self-weight is a concern: retrofit projects with limited support structure capacity, long-span applications where frame costs are driven by self-weight, and corrosive environments where aluminium durability offers long-term savings.
What perforation pattern does D159 use?
D159 web perforated uses pattern 3327 (27%) – 3.3mm diameter holes at 6.0mm triangular centres. This is the same pattern as D137. Open area is 7.6% of the exposed soffit (14.2% of cover area), balancing acoustic absorption with structural integrity and allowing sound penetration in large public venues.
D159 vs D153 – when to choose which?
D153 is 153mm deep with broader material options and moderate spans. D159 is 159mm deep with only two material options but achieves the maximum spans (9.00m solid, 8.00m perforated). Choose D159 when maximum span is the priority; choose D153 when flexibility in material choice or cost optimisation matters.
Where should the VCL sit with perforated D159?
The vapour control layer (VCL) must be positioned underneath the perforated tray when the soffit is exposed to internal building spaces. This ensures moisture does not enter the deck trough, maintains the acoustic benefit of the perforations, and protects the structural integrity of the web.
Ready to Specify RoofDek D159?
Let our specialists design the right solution for your long-span structural requirements. Get a detailed quote, discuss material options, and receive technical guidance tailored to your project.
