Stramit Speed Deck Ultra® Concealed Fixed Decking

  • Wide Cover - fewer sheets and quicker installation.
  • Deep Ribs - stronger and stiffer with better water carrying capacity; roof slopes as low as 1°.
  • Full Length Clips - to locate ribs and compress insulation.
  • Four Fixing Points Per Clip - with centralised fastening for unsurpassed strength.
  • Hexagon Head Screws - bigger, stronger and easier to install, with less wastage.
  • Outstanding Wind Load Resistance - improved security with lower purlin costs.
  • Spring Curving - data for arched and curved roofs.
  • Automatic Bird Proofing - built in accessory with no need for extra components.
  • Independently Tested - by James Cook University Cyclone Testing Station for cyclonic performance - one set of load tables for use anywhere in Australia.   
Australian Design Award 

Stramit Speed Deck Ultra® decking, winner of a 1995 Australian Design Award for “using the properties of high tensile steel to their best advantage through good design practices”.


The visual appeal, strength, wide cover, light weight and weather resistance of Stramit Speed Deck Ultra® decking make it perfect for all commercial roofing applications. Its excellent strength and ease of assembly allow for long, economical spans.The large water-carrying capacity and weather-tightness permit very low roof pitches, leading to economies in the building structure. Stramit Speed Deck Ultra® decking may also be used for domestic applications.


Stramit Speed Deck Ultra® decking is manufactured from hi-tensile G550 colour coated steel or zinc-aluminium alloy coated steel. In some locations galvanised and severe environmental colour coated steel may be available by arrangement. Colour coated steels are in accordance with AS2728 – Category 3 and, for the substrate, with AS1397. Zinc-aluminium alloy coated AZ150 and galvanised Z450 conform to AS1397. Stramit has a comprehensive range of colours as standard. Ask your nearest Stramit location for colour availability. 

SHEETING MASS (kg/m˛ of roof area)
thickness bmt Zincalume Colorbond Galvanised
0.42mm 4.66 4.74 5.07
0.48mm 5.29 5.37 5.70

Adverse Conditions

Stramit Speed Deck Ultra®
decking will give excellent durability in almost all locations. With all of its fastenings protected beneath the decking, Stramit Speed Deck Ultra® decking can be expected to outlast through-fixed roofing. It is however important to choose the correct coating for each application environment. The table below shows the suitability of coating types for different exposure conditions. 

suitability of site exposure condition
coating type benign moderate severe
Zincalume® AZ150 ? ?
Galvanised Z450 ?
Colorbond® XRW ?
Colorbond® Ultra N/A N/A
? Question marks indicate conditions where durability may be diminished, depending on the particular application.

The approximate site exposure conditions in the table above are defined below. 

  distance of site from
site exposure rough calm,still industrial fossil fuel
condition active surf salt water emission combustion
benign 1000m + 100m + 500m + 500m +
moderate 400m-1000m 0-100m 250m-500m 250m-500m
severe 100m-400m N/A 100m-250m 100m-250m
very severe 0-100m N/A 0-100m 0-100m
The suitability and exposure tables above are guidelines only, conditions will vary from site to site. If in any doubt about the choice of coating for a particular application contact your nearest Stramit office for advice.


All building products need to be checked for compatibility with adjacent materials. These checks need to be for both direct contact between materials, and where water runs from one material to another. The following guidelines generally avoid material incompatibility:    
  • For zinc-aluminium alloy coated steel, colour coated steel and galvanised steel roofs avoid copper, lead, green or treated timber, stainless steel and mortar or concrete.
  • In addition galvanised steel roofs should not receive drainage from aluminium or any inert materials, such as plastics, glass, glazed tiles, colour coated and zinc-aluminium alloy. 
Contact Stramit for more detailed information.


Stramit has in-house, purpose built, testing equipment used to design, develop and improve products for the Australian market. In addition many Stramit products are tested or witnessed by independent organisations. These include:     
  • Cyclone Structural Testing Station (James Cook University)
  • The University of Sydney
  • Monash University
  • University of Queensland
  • University of Technology, Sydney 
This ongoing research and development activity ensures that Stramit remains at the forefront of innovation, design and consumer information.

Architectural Specification 

The roofing/walling shall be 0.42 (or 0.48) mm BMT Stramit Speed Deck Ultra® decking in continuous lengths with trapezoidal ribs 43mm high, spaced at 233mm centres. Sheeting material shall be protected steel sheet to Australian Standard AS1397, with a minimum yield stress of 550MPa (Grade G550) and an AZ150 zinc-aluminium coating with or without an oven-baked paint film of selected colour. The sheeting shall be fixed to the purlins/girts in accordance with the manufacturer’s recommendations using patented full length fixing clips supplied. Clips shall be fastened to purlins/girts with screws supplied in accordance with Australian Standard AS3566, Class 3, and attached at every rib. Sheets shall be laid in such a manner that the approved side lap faces away from the prevailing weather. A minimum of 50mm shall be provided for projection into gutters. Flashings shall be provided in compatible materials as specified; minimum cover of flashing shall be 150mm. All sheeting shall be fixed in a workman-like manner, leaving the job clean and weathertight. Repair minor blemishes with touch-up paint supplied by the roof manufacturer. All debris (nuts, screws, cuttings, filings etc.) shall be cleaned off daily.


The spans shown below take account of ‘normal’ foot traffic and wind resistance including local pressure zone effects. Pressures are based on AS4055 or AS1170.2 section 2. Where the two standards differ, the worst case has been taken for each classification. Data should only be used for buildings 7m or less in height, 1000m2 or less in area and unaffected by land topography.

  roofs walls overhangs
Pressure (kPa)   internal
(end) span
Pressure (kPa)   internal
(end) span
strength double
strength double
N1 or Region A (sheltered suburban)
0.42 0.76 1.35 1700 1700 2100(1750) 0.61 1.04 3000 2850 3000(2500) 150 450
0.48 0.76 1.35 2300 2300 2700(2250) 0.61 1.04 3000 2900 3000(2500) 200 500
N2 or Region B (sheltered suburban) and Region A (exposed suburban)
0.42 0.78 1.94 1700 1700 2100(1750) 0.61 1.49 3000 2850 3000(2500) 150 450
0.48 0.78 1.94 2300 2300 2700(2250) 0.61 1.49 3000 2900 3000(2500) 200 500
N3 or Region A (rural) and Region B (exposed suburban)
0.42 1.18 2.96 1700 1700 2100(1750) 0.92 2.25 2600 2350 2900(2450) 150 450
0.48 1.18 2.96 2050 2250 2550(2150) 0.92 2.25 2650 2450 2950(2500) 200 500
Internal spans must have both end spans 20% shorter. Values are only valid for use with steel members of 1.5mm or thicker. For more specific applications Stramit Speed Deck® Ultra Decking must be designed to the pressure and foot traffic limitations below. Spans may exceed those shown in this table, provided the wind pressure and foot traffic limits are not exceeded


per sheet
per purlin
pressure (kPa) at the spans (mm) shown
600 900 1200 1500 1800 2100 2400 2700 3000
  1 clip internal 2.81 2.81 2.53 2.24 1.96 1.68 1.39 1.11 0.83
0.42 and equal 2.86 2.86 2.47 2.08 1.68 1.29 0.90 0.51  
  3 screws double 2.33 2.33 2.08 1.84 1.60 1.36 1.12 0.87 0.63
  1 clip internal 3.12 3.12 2.80 2.49 2.18 1.86 1.55 1.23 0.92
0.48 and equal 3.17 3.17 2.74 2.30 1.87 1.44 1.00 0.57  
  3 screws double 2.58 2.58 2.31 2.04 1.78 1.51 1.24 0.97 0.70
per sheet
per purlin
pressure (kPa) at the spans (mm) shown
600 900 1200 1500 1800 2100 2400 2700 3000
  1 clip internal 7.91 7.91 6.16 5.07 4.32 3.78 3.36 3.03 2.77
0.42 and equal 7.86 7.86 5.82 4.62 3.82 3.25 2.83 2.50 2.24
  3 screws double 8.00 8.00 5.71 4.40 3.55 2.97 2.54 2.21 1.95
  1 clip internal 8.55 8.55 6.65 5.47 4.67 4.08 3.63 3.27 2.99
0.48 and equal 8.49 8.49 6.29 4.98 4.12 3.51 3.05 2.70 2.42
  3 screws double 8.64 8.64 6.17 4.75 3.84 3.20 2.74 2.39 2.11
Tables based on testing to AS1562 and AS4040 parts 0.2 and 3. Internal spans must have both end spans 20% shorter.
Values only valid for use with steel support members of 1.5mm or thicker.

Foot Traffic

Foot traffic limits for Stramit Speed Deck Ultra® decking are shown for three alternate foot traffic categories. 

These are:     
  • High Maintenance – for applications with repeated maintenance, particularly where personnel may be unfamiliar with correct procedures for walking on metal roofs.
  • Normal – based on traditional expectations, with moderate maintenance foot traffic using designated foot paths.
  • Controlled – spans that conform to AS1562 but require minimal careful foot traffic only on the designated foot path. Suggested for use only where occasional aesthetic imperfections from foot traffic are acceptable.
foot traffic limits
high maintenance normal controlled
  internal 1100 2100 2700
0.42 equal 700 1700 2250
  double 700 1700 2250
  internal 1400 2700 3600
0.48 equal 900 2300 2700
  double 900 2300 2700
Tables are based on tests to AS1562 and AS4040 parts 0 and 1

For more information on foot traffic performance of Stramit Speed Deck Ultra® decking and other Stramit® roofing profiles refer to Stramit’s Foot Traffic Guide.

Spring Curving 

Stramit Speed Deck Ultra®
decking can be spring curved, concave and convex, including curved ridges, provided it is within the recommended limits below:   

restricted minimum* unrestricted unrestricted
0.42 bmt 0.48bmt minimum maximum
90* 70* 100 225
*At these radii a maximum support spacing of 1200mm applies, and limit state pressure capacities are reduced by 14% for serviceability and 7% for strength.

For more comprehensive information on spring-curving Stramit Speed Deck Ultra® decking and other Stramit® roofing profiles refer to the Stramit® Spring Curving Guide.

Designing for Snow 

Concealed fixed decking such as Stramit Speed Deck Ultra® decking is the preferred roofing material in alpine areas. This, and many other design suggestions, can be found in Australian Standards HB 106 – ‘Guidelines for Design of Structures in Snow Areas’. Particular attention is drawn to maintaining an adequate roof slope for snow shedding, and screw fixing of deck pans beneath the ridge capping. Downward load capacities for Stramit Speed Deck Ultra® decking have not been tabulated, but can be assumed to equal the outward capacities shown.

Thermal Expansion 

All metal roof sheeting is subject to thermal expansion and, where there is a temperature difference between the sheeting and the structure, this needs to be accommodated. The colour of the sheeting will affect the amount of thermal expansion, and whether the sheet is flat or curved will affect its ability to resist without problems. 

Stramit Speed Deck Ultra
® decking has excellent resistance to the problems associated with thermal expansion. Nevertheless sheet lengths should be limited to those shown below. 

roof colour light dark
Flat 35 25
Spring-curved 30 20

Significant failures of pierced fixed roofing have occurred on commercial buildings where dimensional changes from thermal expansion have not been accurately incorporated in the roof design. These can result in elongation of fastener penetrations, consequent water leaks, fastener failure and unacceptable frictional noise.Through-fixed profiles which incorporate special sealing may exacerbate these problems.

Water Carrying

Stramit Speed Deck Ultra
® decking has excellent watercarrying capacity. This and the decking stiffness enable roof slopes to be as low as one degree for many applications. Roof run lengths are the combined lengths of all roof elements contributing to a single pan drainage path. This can include the roof length upstream of a roof penetration that concentrates flow into other pans. The table below gives slopes for 100 year return period rainfall intensity.

Rainfall Intensity
total roof run length (m)
50 60 70 80 90 100 110 120 130 140 150
150   1.0 1.1 1.4
175 Minimum   1.0 1.1 1.4 1.8 2.2
200 Slope 1°   1.0 1.3 1.7 2.2 2.6 3.1
225   1.0 1.4 1.9 2.4 2.9 3.6 4.2
250   1.0 1.4 1.9 2.6 3.2 3.9 4.7 5.5
275   1.0 1.3 1.9 2.6 3.2 4.0 4.8 5.8 6.8
300   1.0 1.1 1.7 2.4 3.1 4.0 4.8 5.9 6.9 8.2
325   1.0 1.4 2.1 2.9 3.8 4.8 5.8 6.9 8.2 9.7
350 1.0 1.1 1.7 2.6 3.5 4.5 5.5 6.8 8.2 9.8 12
375 1.0 1.5 2.3 3.2 4.3 5.5 6.8 8.1 10 12 14
400 1.4 2.0 2.7 3.9 5.1 6.3 7.7 9.7 12 14 17

For more information on water carrying performance of Stramit Speed Deck Ultra® decking and other Stramit® roofing profiles refer to Stramit’s Roof Slope Guide. Stramit’s CD-ROM ‘Solutions in Steel’ contains data for most locations. 

Maximum water protection is also ensured by the absence of fastener penetrations when using Stramit Speed Deck Ultra® decking.

Darwin Area 

Information on the use of Stramit Speed Deck Ultra® decking in the Darwin area can be found in deemed-tocomply sheets No M/125/1 and M/125/2. These are available from Stramit.


All fastening screws must conform to AS3566 - Class 3. For connecting clips to purlins use: 

  For steel (0.75bmt or greater)
- No.12 x 30mm hex-head self-drilling and threading screws (available pre-loaded into clips in some locations)
  For timber (F11 or better)
- No. 12 x 50mm hex-head type 17 self-drilling screws

Stramit Speed Deck Ultra® decking Clip - supplied in easy to handle boxes of 40 clips
Stramit Speed Deck Ultra® decking End Cap - used with silicone sealant for roof penetrations


Stramit Speed Deck Ultra® decking is readily installed with or without fibreglass insulation blanket. If practical lay sheets in the opposite direction to prevailing weather. Installation of Stramit Speed Deck Ultra® decking is a straightforward procedure using the following fixing sequence:
  1. Ensure all purlins are in line and correctly installed. Using a string line or the edge of the first sheet, align the first row of fixing clips. Screw the clips to the purlins in the same order as the direction of laying.
  2. Locate the first sheet over the clips with the correct projection at each end of the sheet. Snap each rib on to the clip at every purlin, always in the order of the direction of laying. Note – Do not use undue force; the deck will easily accommodate clip entry.
Snap ribs on to clip in order – 1-2-3
  1. Hinge next clip about trailing edge of the first sheet, allowing it to fall to the purlin. Ensure correct fitting to the deck edge and that it is sitting on the extended tail of the preceding clip. Align fixing holes together then fasten clip to purlin as before.
  2. Continue to lay sheets as before. From time to time measure coverage of sheets at ridge and eaves to maintain squareness.
  3. At end of purlin cut fixing clip (and, if necessary, the roof sheet) to suit.
  4. Turn up ends of sheet at ridge and turn down eaves ends into gutters using the Stramit Speed Deck Ultra® decking turn up/down tool.
  5. Secure leading and trailing edge of the roof with a full or cut-back clip, or sealed fasteners through the roof tray, at every purlin. Cover these with side flashings. Install all flashings as required to weatherproof and complete the roof.
  6. Clean the roof after each day’s work, removing all screws, cuttings, swarf etc, and leave roof clean and watertight. Repair any minor blemishes in colour coated finishes with Stramit supplied touch-up paint. 
Each clip box has an illustration of the basic clip fixing technique. A more detailed ‘Installation Procedure’ leaflet (with clear illustrations) is available to assist fixers on site. Ask for a copy to be sent with your order.


As with all roofing products, Stramit recommends extra caution be taken when walking on the roof. When walking on Stramit Speed Deck Ultra® roofing always wear flat rubber soled shoes and place feet only in the pans, taking care to avoid the last pan or two near edges of the metal roof area.


The unique Stramit Speed Deck Ultra® decking full width clip compresses blanket during installation making fixing easy. Blanket up to 100mm in thickness can be readily used. High thermal efficiency can be achieved by using Styrofoam blocks laid between the blanket and the fixing clips. Contact Stramit for further information.

Unsupported Underlaps 

Free underlap sheet edges, such as may be encountered when using translucent sheeting, may need additional support. Use a 40mm x 40mm x 1.0mm trim angle beneath the underlap and screwed to the purlins if spans exceed 1500mm for 0.42bmt, and 2000 for 0.48bmt.

Good Practice

Stramit recommends that good trade practice be followed when using this product, such as that found in Australian Standards Handbook HB39.


Stramit Speed Deck Ultra® decking can be easily cut, where required, using a power saw with a steel cutting blade or a power nibbler and, for localised cutting, tin snips. Avoid the use of abrasive discs as these can cause burred edges and coating damage. Please dispose of any off-cuts carefully.


Prices on Stramit Speed Deck Ultra® decking and its accessories can be obtained from your nearest Stramit location or distributor of Stramit® products. As Stramit does not provide an installation service, ask your tradesperson for a supply and fix price. Contact your nearest Stramit location for the names of tradespersons in your area.

Related Products

Ridge Capping
standard or custom dimensions
a range of custom flashings
Filler Strips
top and bottom; for eaves, ridge and joint sealing
Use only where sealing is preferred to ventilation
Insulation & roofing mesh
a range of mesh, sisalation, plain & foil backed blanket
Translucent sheeting
fibreglass sheeting in a range of shades and densities


Stramit Speed Deck Ultra® decking is supplied cut-to-length. When designing or transporting long products ensure that the length is within the limit of the local Transport Authority regulations. The manufacturing tolerance on the length of product supplied is +0, -15mm.


Stramit Speed Deck Ultra® decking can be ordered directly, through distributors, or supplied and fixed from a roofing contractor. 


Delivery can normally be made within 48 hours, subject to the delivery location, quantity and material availability, or can be at a pre-arranged date and time. Please ensure that suitable arrangements have been made for truck unloading, as this is the responsibility of the receiver. Pack mass may be up to one tonne. When lifting Stramit Speed Deck Ultra® decking, care should be taken to ensure that the load is spread to prevent damage. 


Stramit Speed Deck Ultra® decking should be handled with care at all times to preserve the product capabilities and quality of the finish. Packs should always be kept dry and stored above ground level while on site. If the sheets have become wet, they should be separated, wiped and placed in the open to promote drying.


Exterior surfaces of metal products unwashed by rain can benefit from occasional washing to remove build-up of corrosive salts. Walls beneath eaves or awnings are such a situation.

Further Information 

As well as our standard range of Technical Manuals, Installation Leaflets, Case Studies and other promotional literature Stramit has a series of Guides to aid design. 

These include:     
  • Concealed Fixed Decking
  • Roof Slope Guide
  • Foot Traffic Guide
  • Bullnosing, Curving and Crimping
  • Acoustic Panels
  • Cyclonic Areas
  • Spring Curving Guide 
Please contact your nearest Stramit location for any of these guides or other literature.

Other Products

Stramit offers a wide range of building products, including:     
  • Purlins and girts
  • Formwork decking
  • Roof and wall sheeting
  • Lightweight structural sections
  • Truss components
  • Gutters and downpipes
  • Fascias
  • Custom flashings
  • Insulating products
  • Fasteners   

Stramit Speed Deck Ultra® decking is the subject of four patent and two registered design applications in Australia and patents overseas.


In preparing this document reference has been made to:     
  • Standards Australia Handbook – HB39
    (Installation code for metal roof and wall cladding)
  • Standards Australia Handbook – HB106
    (Guidelines for the design of structures in snow areas)
  • BlueScope Steel – Technical Bulletin TB-4
    (Maintenance of prepainted steel roofing)
  • BlueScope Steel – Technical Bulletin TB-1
    (Steel roofing and walling products – selection guide)

This product was added to our catalog on Monday 13 July, 2009.

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