Sep 20 2006
In its search to adopt eco friendly construction products, the construction industry could be well placed to look backwards in time rather than forwards, according to experts from CERAM Building Technology (CBT).
Under pressure to comply with Government pressure to adopt “green” practices for construction, the industry might be surprised to discover that the solution could rest with methods that were used in the past, rather than new solutions.
Modern cements and mortars, for example, were developed to speed up the build process as the “old fashioned” limes were considered too slow to cope with the demands for new housing. Lime mortars instead became relegated to projects such as heritage developments where more traditional build methods were demanded.
However, as emphasis has begun to move away from speed and towards sustainability, lime mortars may once again prove a valid solution.
According to CBT’s Dr Andrew Smith, the reason for this is simple; “Lime mortars are a great deal more energy efficient, both in terms of production and product life, than modern cements is.”
Some house builders and developers who are keen to demonstrate their green credentials are already using hydraulic lime for mortar, and in fact a number of traditional cement manufacturers are already offering it as an alternative.
Another area where modern methods are losing out to more traditional building techniques is in the area of thermal mass of a building. Simply put, thermal mass works in a similar way to a storage heater in the home. Heavyweight brick and block constructions have excellent thermal mass in that they are able to regulate and control the heating of a building. In the summer months when it is hotter they maintain the indoor temperature, as the bricks and blockwork adsorb the heat. In the winter, they release heat gradually over a period of time therefore ironing out the peaks and troughs, thus reducing the need to have the heating on for long periods of time.
More modern, lighter weight (framed) constructions are more reliant on separate insulation with a lower thermal mass which results in the occupants being more reliant on energy intensive cooling and heating systems.
The projected temperature rise in the UK could see summer temperatures rise by 1-20C on average by 2050. The result is that the heavyweight homes will be more comfortable to live in (temperature wise) than those built from lightweight constructions systems where the insulation will make it difficult to regulate the indoor temperature without the need for a supplementary cooling system.
Another environmentally friendly solution to achieving sustainability is through the use of dry, unfired clay bricks, as they have two significant advantages over other products. Firstly they have a very high thermal mass, and secondly they are extremely good at regulating indoor air quality in terms of humidity.
This can help alleviate a major cause of respiratory problems and can bring particular benefits to those who suffer from asthma or other breathing related problems.