Gulf Construction Online - Rockwool 'superior product'

Insulation

Rockwool 'superior product'

Madinah-based rockwool factory Azel, one of the El-Maimani group of companies, provides an insight into why rockwool offers superior insulation.

01 December 2002

Rockwool is a product of smelting basalt rocks in kilns at temperatures reaching up to 1,400 deg C. The molten liquid is then poured in fast-rotating cylinders that spin at 4,000 rpm to produce fibres, which are collected, bonded together with special thermosetting resin and arranged in rolls and sheets of rockwool.

This process of converting rocks into wool threads involves converting the density of the rock from 3,000 kg /cu m to only 509 kg /cu m.

Therefore, rockwool has all the chemical properties of basalt with only the difference being in density and thus offers the following advantages:

Efficient thermal insulation where thermal resistance of rockwool reaches up to 1.34 sq m D/watt, compared with red bricks thermal insulation of 0.42 and cement block of 0.14;

Effective sound insulation, where the sound transmission factor of rockwool reaches 44 degrees with 100 per cent sound absorption. These values exceed international specifications for hotel, hospital and office buildings;

Does not burn and is inflammable up to 800 deg C;

Does not release toxic or other gases in the event of a fire.

Does not disintegrate like petrochemical-based products and its lifespan is equal to that of the building.

Rockwool is expected to gain popularity, thanks to its outstanding thermal, sound insulation and fire resistance characteristics, in view of the high costs involved in generating electricity and the anticipated increases in the future. Scientific and application findings have concluded that thermal insulation saves up to 70 per cent in power consumption. With the availability of this documented data, it is expected that local demand for rockwool will grow steadily.

Current production amounts to 10,000 tonnes per year and Azel estimates demand to rise to about 30,000 tonnes with the anticipated increase in the number of residential and industrial projects.

Rockwool is composed of interwoven synthetic 5-15 micron tiny fibres which have high flexibility, low density and high resistance to chemical corrosion - all characteristics which make it a good insulation material.

The chemical composition of basalt is very close to that of rockwool. During the smelting process, basalt is used either alone or with additives such as limestone or dolomite and the fibres are extracted from the molten matter.

The product has recently been used for the internal partitions of Jeddah Hilton to provide total room privacy.

The main reason for using rockwool for sound insulation is that it is not flammable which ensures that internal partitions satisfy both sound insulation and fire resistance requirements.

The designer of Jeddah Hilton Hotel decided to use rockwool in the partitions in the building to serve two functions with the same degree of efficiency at no extra cost.