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Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Tech-Dry Building Protection Systems Pty Ltd
Cleaner Production - Water-based Building Protection Chemicals

Tech-Dry Building Protection Systems Pty Ltd has developed a range of water-based water repellent materials for the building industry. These water-based formulations have replaced the solvent-based formulations previously used by Tech-Dry.

Background

Tech-Dry Building Protection Systems Pty Ltd was formed in 1982, and specialises in the development and supply of materials for the prevention of rising damp and water repellents for the building industry. In common with other companies in the building protection industry, Tech-Dry initially used solvent-based products. However, in conjunction with Victoria University they have developed a range of water-based compounds for the prevention of rising damp. Over the past five years (to 1997) the company has made significant investments in research and development, which has resulted in the development of a number of environmentally friendly products and processes for the building industry.

These include:

The Process

Traditional methods of providing dampcourse protection to houses and buildings suffering from salt damp have involved the use of DCFs that consist of a reactive silicone compound in a hydrocarbon solvent carrier.

The DCF is applied to the surface requiring treatment, by saturation flooding at low pressure. These products typically contain five per cent silicone compounds and 95 per cent carrier solvent. The solvent acts solely as a carrier to deliver the active silicone compound into the interior of the substrate. After application the solvent evaporates into the environment and plays no further part in the process.

An average residential property requires in the range of 300 litres of DCF, therefore approximately 285 litres of solvent is emitted to the atmosphere via evaporation over a period of time.

Additionally, solvent-based products present problems due to flammability and odour. Dangerous goods handling and storage requirements must also be met when using solvent-based products.

Cleaner Production Initiative

Tech-Dry has developed a series of DCFs and water repellents that do not contain hydrocarbon solvents. The products consist of special silicone compounds which are either emulsified with, or dissolved in water to form stable solutions. The products have a performance equal to the hydrocarbon solvent based products, but with the advantages that they do not release hydrocarbons on use, and are not flammable or corrosive. The three main products are:

Application of DCF is achieved by a diffusion process whereby:

Research and development work is currently being undertaken to develop water protection products for wood, which will aid in the prevention of dry and wet rot of wood structures in the building industry.

 

Application of Tech-Dry's damp coursing fluid

Application of Tech-dry's damp coursing fluid

Advantages of the Process

The formulation of the water repellent protection materials has changed from 95 per cent solvent to 90 per cent water. This has eliminated use of approximately 26,000 litres of solvent per year by Tech-Dry.

The advantages of this technology are:

It is estimated that in Australia, approximately 3,000-4,000 tonnes of hydrocarbon solvent are released to the atmosphere every year due to the installation of silicone damp courses and the surface impregnation of building structures.

Cleaner Production Incentive

Tech-Dry initiated the switch from solvent to water-based products because of their awareness that solvent-based formula impacts on the environment, including contributing to photochemical smog, occupational health and safety concerns and their awareness of trends in both the USA and Europe to place limits on solvent contents of various consumer products.

In addition, there was an increasing consumer demand for non-toxic and odourless products.

Barriers

The main barrier to further adoption of the water-based technology in the building protection industry has been the lack of any specific environmental legislation aimed at moving away from traditional solvent-based products.

Further Developments

In 2001, Tech-Dry continues to develop and modify products aligned with cleaner production principles based on similar technology to the initiative explained above. In particular, in 1996, a water-based admixture (additive) was developed to make concrete blocks and pavers and also rammed earth water repellent, eliminating the use of post-construction solvent-based sealers.

Contact

Dr Doug Kagi
Managing Director
Tech-Dry Building Protection Systems Pty Ltd.
177 Coventry Street
South Melbourne  VIC 3205
Ph: (03) 9699 8202
Fax: (03) 9696 3362
Email: doug@techdry.com.au
Casestudy implementation: 1994
Further initiatives: 1996
Casestudy initially prepared: February 1997 by Australian Centre for Cleaner Production
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Last modified: May 2001