Introduction
From caves to the wattle and daub houses to huts and from there on into buildings, rising up sky high, mankind has come along way since then, turning the globe into a much bigger and better place to live in. At present the earth is running out of resources due to the high consumer rates. Hence analyzing the importance of the growing demand for alternative building materials in the Sri Lankan Construction Industry, Durra Building Systems (Pvt) Ltd, a fully owned subsidiary of International Construction Consortium Limited has embarked on a modern, innovative project to manufacture multipurpose building panels of paddy straw.
Teaming up with Ortech Industries (Pvt) Ltd in Australia, Durra Building Systems (Pvt) Ltd is geared with the latest tools of technology and enhanced construction techniques to bring about the product with a fine finish. Durra ensures a proven 40 year track record in Australia, New Zealand, USA, Philippines and Indonesia.
 Surrounded by the cool, blue waters Sri Lanka has a proud agricultural history. In terms of keeping up with tradition with a touch of modern day technology, the Durra Straw Board Manufacturing Plant is located at Minneriya - the hub of the paddy cultivating area in the North Central Province. The paddy straw is sourced direct to the plant providing golden opportunities to the farmers in the area to boost their income to a desirably higher level.
Making use of the natural resources with minimum wastage, Durra Building Systems (Pvt) Ltd has come up with an eco friendly product, The Durra Straw Panel, using paddy straw, considered an agricultural waste that would if not have been burnt and destroyed after the harvest. The straw panel is fire resistant, strong and durable with impressive thermal and acoustic properties.
The manufacturing process is easy with a low energy consumption of 5MJ/m2, and liberates no hazardous toxic waste as by products. A wide range of alternative finishes and textures can be applied in order to obtain the final product.
Durra building panels are manufactured in two different thicknesses of 50mm and 58mm for ceilings, partitioning and internal wall cladding. The panels are available in standard sizes of 8’ x 4’ and can be adjusted to suit the customers’ requirement.
General
 Combining the physical forces with the properties of matter the Durra technique is a unique, dry extrusion process facilitated under extreme thermal and pressure conditions, leading to the formation of a strong, recyclable, water resistant, solid panel core. Chemical binding agents, glues or resins are not added whatsoever in the process of panel core production.
This high performance wall system is rich in productivity since it’s affordable, requires limited labour and the installation process is less time consuming. Its durability, strength and recyclable properties with flexible acoustic design options will assure that this innovative system will certainly take you onwards and upwards and to greater heights in your construction projects.
We provide practical construction solutions that are socially beneficial to the country and give prominence to our valued customers, in order to satisfy their requirements and maintain high quality standards.
Proven Performance- Durra Wall System
The Majestic Cinemas in the United States, Warner Brothers Sound Studio, Media Centre where the Olympic Games were held in the year 2000, the Central City Studios and Colonial Stadium in Melbourne, Australia are a very few of the many pieces of evidence that prove the spectacular performance of the Durra Wall System. Safe, rapid and economical installation leaves Durra, highly versatile with the ability to perform multipurpose tasks.
A rich quality product in the Building & Construction Industry, Durra Wall System is cost effective with outstanding acoustic properties, high fire resistance and a natural alternative for environmentally sustainable design, considered an excellent thermal insulating medium.
Durra Easiwall System
The Durra Wall System is self supportive, requires no timber stud framing and its construction time span is minimal in comparison to similar dry wall systems and the cost of materials are distinct and comparable.
Durra Easiwall Panel is manufactured with tapered long edges and uses a patented mechanical biscuit system. For the ease of running electrical cables through the wall it consists of conduits with a diameter of 25mm in each panel.
Clean and cut to provide a strong, durable wall, it is easy to construct, resulting in a dry, lightweight system with a touch of tradition in style at a remarkable, competitive price. The essence of the system is the use of a simple and effective Patented Biscuit Connection System, which locates and secures the wall panels together at vertical panel to panel joints. Following installation a skim coat of plaster is applied to all vertical joints between boards and abutments. For better results a plaster jointing system is recommended.
Depending on the project, the Durra panel can be painted, textured or wall papered to full fill your requirements. The Durra panel is self supportive between top and bottom, fixing heights of about 2700mm and does not require additional framing. The architraves and fixing boards can be fixed into place after completion of the Durra wall. Nail and screw fixing can be done on the panel as you desire.
Applications
Durra Building Panels are ideal for
 
- Internal wall cladding
- Ceilings
- Partitioning (full/half) incorporated with glass and aluminium extrusions
Be it your dream home, a commercial complex, Hospital with great health care services, condominiums, work place or a hotel to relax and entertain, Durra Panels will build it into a reality with its multipurpose, outstanding performance that can handle any task at any risk. Its sound proof, high impact and fire resistance creates opportunities to make the maximum use of this durable building panel in theatres, convention halls, airports, sound studios, gymnasiums and sports complexes.
Components
 
Durra Panel
Once known as the Granary of the East, Sri Lanka is an island rich in natural resources. Making an attempt to blend tradition with today’s trends, the Durra Building panel made of paddy straw is a proud product of Sri Lanka. Facilitating the required extreme heat and pressure conditions the liberation of a polymer from the paddy straw acts as a natural binding agent in the formation of the solid core. The manufacturing procedure is an innovative, chemical free dry extrusion process.
Durra Biscuit Connectors
Durra Biscuit Connectors form panel to panel joints and consists of five biscuits per panel that allow a simple, fast and effective self aligning wall system.
Galvanized Channels and wooden bars prevent any deflection at both floor and head track junctions.
Testing - Proving our strengths and capabilities
Panel Strength
With the load testing inspection conducted by the University of Moratuwa the Durra Panel has proved its powers and strengths where a horizontally installed panel is capable to support a uniformly distributed excess load of 3KN and a point load of 1.5KN. Load testing conducted by the Australian Standards, eg: CSIRO gives evidence that the horizontally installed Durra Panel supports an excess load of 1000 kilograms and a point load of 100 kilograms.
Acoustic
Across the width of a typical 50mm Durra Panel Wall system the STC (eg: sound transmission loss) is about 52 and in a single board it is about 32. Greater the STC value, greater the acoustic performance of the wall.
Material STC Comparisons
| 70mm Timber Stud Frame internal 10mm Plasterboard & 10mm Plasterboard externally |
28 |
| 58mm Durra Panel |
34 |
| 50mm Durra Panel |
32 |
Fire
 
Durra Panel is a natural fire resistant construction material with a densely compressed panel core, which is carbonized when exposed to fire and remains unaltered for a long duration of time. This wall system where the UL testing has been conducted in the United States offers a 1hr fire rating which can be extended to 2hrs where required.
Documentation including test results can be provided to verify the results quoted above.
The FRL (Fire Resistance Level) of the joint Durra Panel is 60/60/60 all inclusive of structural adequacy, integrity and insulation, which is the assessment criteria put forward as the three performance measurements by Australia.
Impact Resistance
CSIRO’s comparative impact resistance test proves that it has an impact resistance 11 times greater than the 10mm impact resistance plasterboard sheeting. The test involved dropping a 100mm diameter cast iron ball of about 3.62Kg on different products from a wide range of heights.
The University of Moratuwa subjected the panels to a load of 4.5Kg with a maximum drop height of about 4m to further test the abilities of this multipurpose board and confirm that the panels did not under go any sort of damage.
Material Damage
| 58mm Durra Panel |
4mm dent, paper fractured, minimal damage |
| 13mm impact resistant plasterboard |
25 mm deep dent significant damage |
| 10mm plasterboard |
110mm diameter hole |
Thermal
The 58mm thick Durra panel provides a thermal resistance of about 0.72m²K/W and a zero thermal conductivity.
| MATERIAL |
R (m2K/W) |
K (W/mK) |
| glass fiber batts- 48kg/m3 @ 50mm |
1.52 |
0.033 |
| polystyrene- 16 kg/m3 @ 50mm10 deg.C |
1.43 |
0.035 |
| 58mm Durra Panel |
0.72 |
0.081 |
| 50mm Durra Panel |
0.62 |
0.081 |
| 90mm brickwork |
0.11 |
0.81 |
| 16mm plasterboard |
0.094 |
0.17 |
| 90mm brickwork- fire clay |
0.078 |
1.15 |
| 13mm plasterboard |
0.077 |
0.17 |
| 100mm concrete |
0.069 |
1.44 |
| 10mm plasterboard |
0.059 |
0.17 |
| 6mm cement set |
0.019 |
0.32 |
| 6mm oat- glass |
0.006 |
1.05 |
| metal deck roofing |
0.0 |
0.0 |
Material Handling
 
Durra panels come in packages of ten or twenty sheets per pack. Though the size of the pack is generally determined by the length of the sheet, specific packing requirements can be negotiated to suit our valued customers.
Cranes
- Use synthetic slings rated for specified loads to lift packs
- Prevent crushing of panels during the lifting process
- Avoid damaging panel corners
Forklift or Similar
Place fork tines direct under the pack
Manual Handling
- Lift and tilt one corner up in order to provide support to the panel prior to lifting
- Carry panel on the edges – do not place horizontally
- Remove surface dirt or grit before re-stacking
- Avoid sliding panels
- Place first panel of the stack on billets
Exposure to Weather
Though the panel can with stand varied weather conditions such as solar energy, wind and rain for at least a short period of time, the Durra panel core must be free of moisture during the manufacturing process. Make sure that the panels have no damage, cuts or tears and that all cut edges must be sealed with specialized reinforced aluminium foil tape.
Environmental
As the world strives for excellence it is also drawing closer to destruction which is a serious issue that should be given much attention. Today’s market is very demanding where toxic wastes, efficiency, indoor air ventilation and recycling methods matter in the field of building & construction.
Therefore to beat the challenge and keep up to the sky rocketing demands we provide the ideal solution where there are no binding agents used and no toxic waste released with a minimum energy consuming manufacturing process of the Durra panel made of straw, a naturally renewable material.
| MATERIAL |
(MJ/kg)
| (MJ/m2) |
| 58mm Durra Pannel |
0.36 |
5.0 |
| glass fiber batts- 18kg/m^3 @ 50mm |
30.3 |
27.3 |
| 10mm- plasterboard |
6.1 |
33.0 |
| polyester batts- 18kg/m^3 @ 50mm |
53.7 |
48.3 |
| 13mm- plasterboard (5,890 MJ/m^3) |
6.1 |
51.9 |
| 16mm- FR plasterboard (5,890 MJ/m^3) |
6.1 |
70.8 |
glass fiber batts- 48 kg/m^3 @ 50mm |
30.3 |
72.7 |
| 90mm concrete brickwork |
0.94 |
106.7 |
| metal deck roofing- galv steel 273,180 MJ/m^3 |
34.8 |
208.8 |
| 100mm concrete- precast @ 2.4 ton/m^3 |
2 |
480 |
| 90mm brickwork- fire clay (15,210 MJ/m^3) |
25 |
1,368.9 |
Specific Test References
- Acoustic
Acoustic System Acoustical Research Facility
Laboratory Report on Sound Transmission Loss Test – Report No AS-TL1863 (31 July 2001) |
Acoustic System Acoustical Research Facility
Laboratory Report on Sound Transmission Loss Test – Report No AS-TL2033 (15 August 2002) |
Royal Melbourne Institute of Technology
Report on the Determination of Airborne Sound Transmission Loss – Roof System
Report No 1211/03-035/PD (22 July 2003) |
Royal Melbourne Institute of Technology
Report on the Determination of Airborne Sound Transmission Loss – Wall System
Report No 1211/03-035/PD (22 July 2003) |
- Fire
AWTA Textile
Early Fire Hazard Indices Testing Report 7-517736-CV (25 March 2003) |
CSIRO Manufacturing & Infrastructure Technology
Assessment No FCO-2230 (4 June 2003) |
CSIRO Manufacturing & Infrastructure Technology
Test No FNK 0050 (23 October 2003) |
National Building Technology Centre
Early Fire Hazard Properties of Materials Report No E5288 (20 October 1987) |
National Building Technology Centre
Fire Resistance Report No 20 (18 October 1987) |
National Building Technology Centre
Fire Resistance Report No 96 (21 February 1989) |
- Impact
University of Moratuwa – Sri Lanka - 6th June, 2006External Investigation for Durra Panels as partition and Ceiling Boards |
CSIRO Building, Construction & Engineering Report BCE Doc 01/202(M)
Comparison of Impact Resistance of Easiwall Panels (May 2001) |
- Thermal
Southwest Research Institute, Chemistry & Chemical Engineering Div., Dept. of Fire Tech
Report on Thermal Transmission Properties of Panel – SwRI Project No 01.04918.01.050 |
R.H. Harry Stranger (Incorporating Henry FAIJA & Co) Material Consultants
Report of Test or Thermal Conductivity of Strawboard, Ref 4126/63 Test No P112l/74 |
- Structural
University of Moratuwa – Sri Lanka - 6th June, 2006External Investigation for Durra Panels as partition and Ceiling Boards |
CSIRO Building, Construction & Engineering
Report on Structural Testing of Ortech Panels (November 2000) |
Keleher & Associates Consulting Engineers
Job No 03845 (September 1999) |
Keleher & Associates Consulting Engineers
Job No 03855 (October 1999) |
Technisearch Engineering & Scientific Services
Load Testing of Stramit Ceiling Panels for Qantas Airways – Job No 935-1520 (19 April 1994)
|
Technisearch Engineering & Scientific Services
Letter regarding the Load Testing of Stramit Board Panels (5 January 1993)
|
Queensland Institute of Technology
Racking Load Test on Easiwall Panels – Report No CET 1079 Folio 3 (14 October 1983)
|
Royal Melbourne Institute of Technology
Uniformly Distributed Load Detection Tests (28 February 1967) |
Royal Melbourne Institute of Technology
Load Tests – Floor Panels (4 May 1967) |
|
