<p>Ventilation Ventilation Ventilation!</p>
In this article, David Currier from Marley Eternit discusses the myths surrounding vapour permeable underlays and outlines the advice merchants should be giving to customers on correct ventilation.
Correct roof ventilation is vital because, without it, cold and damp conditions can cause condensation to form on both the underside of the roof tiles and slates as well as the roof underlay, causing droplets of moisture to form in the batten void and roof space.
There is a common roofing myth that if you use a vapour permeable underlay, then you don’t need to worry about ventilation. That simply isn’t the case and this has become such an issue in new properties that the NHBC recently issued guidance that all pitched roofs with insulation at ceiling level should always be ventilated to the outside air to minimise the risk of condensation.
When selling both vapour permeable and impermeable underlays, merchants need to be aware that the ‘Code of practice for the control of condensation in buildings’ (BS 5250) recommends ventilating roof spaces and voids as a proven method of reducing the risk of harmful condensation in roofs.
Click here to find out more and to read Marley Eternit’s top ten tips to prevent condensation.