Rainscreening
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What is it?
Of key importance to many projects which Almura has been involved in, is the ‘rainscreen principle’, which, although not a new concept, allows for extremely effective thermal insulation. Due to the potential movement of any building and break down of exterior materials the rainscreen principle is ideal in countries such as the UK, whose climates tend to include a lot of driving wind and rain.
The technology
The outer cladding deflects most of the driven rain. Behind the cladding is a ventilation cavity which is openly vented at the base and head of the cladding. This cavity allows air in at the base of the cladding and expelled at the head of the cladding. The air pressure in this cavity is always equal to that of the outside, therefore any rain trying to penetrate any joints finds it virtually impossible to do so.
The ventilation cavity allows any condensation or possible penetrated rain water to be either ventilated out of the system or to run down the back of the cladding and out at the base. At the same time the buildings internal moist air migrates through the walls, insulation etc., and is vented through this cavity allowing the building to ‘breathe’.
Battens of either aluminium or timber are used to create this cavity. The system allows great flexibility to improve thermal insulation of the building.
Its relevance
With Government plans to make all new builds ‘carbon neutral’ by 2016, experts predict this will add an average of £640 on to the cost of each new house, and just over a third of this will be spent trying to generate and conserve heat in the properties.
A quarter of the UK’s current carbon emissions – around 150 million tonnes of carbon dioxide each year – are produced via heating of homes, lit and generally run. So, it is more important than ever that homes are well insulated and it’s also crucial that homes are designed to be more resilient; given the extreme climate changes that will be experienced over the lifetime of the home.
Utilising the rainscreen principle, Almura consistently demonstrate their capability in providing products to increase sustainability, reduce carbon emissions and meet the demands of an energy-efficient future, in both housing and construction in general.