How much mould is too much mould
Benchmarking mould levels in UK properties
The UK media frequently report that a certain number – or a certain proportion – of the country’s homes suffer from mould problems.
But how do they know how many houses are affected? And what counts as a mould problem in the first place?
‘Do you have a mould problem?’
Even when gathered by reputable organisations, statistics regarding mould problems are usually collected through interviewing householders and asking them whether their home has mould growing in it (and sometimes ask if there are signs of water damage or suspicious smells). They will also usually provide householders with some metric so that they can describe how bad the problem is.
These surveys therefore rely largely on householders’ own perception of a problem and how serious that problem is. And they take no account of the mould problems that householders cannot see – as is often the case when mould grows behind furniture
So, is there a more rigorous method for gathering information about levels of mould contamination in UK properties?
A rigorous method – and a benchmark
A research team from the Centre for Moisture in Buildings based at University College London are attempting to address exactly this problem – with help from us at HouseTest.
The team at UCL is aiming to establish a standardised and robust method of measuring indoor mould – along with a benchmark for what counts as a ‘normal’ or ‘acceptable’ level of mould inside. HouseTest are providing the project with qPCR DNA testing so that mould problems, both hidden and visible, can be quantified.
Why is it difficult to measure mould levels in buildings?
As the project leaders explain, the main reason is that most mould is not visible, but is airborne. So in order to understand the condition of a house, we have to measure the levels and perhaps also the types of mould in the indoor air (as well as sampling any visible mould). But how do we measure mould in the air? And what type or part of mould should we be seeking to measure? How do these also relate to mould on surfaces?
It is because these questions have not been adequately answered in independent rigorous research that it is currently impossible to say what an acceptable level of mould in a building is, and at what point mould concentrations exceed this level.
