Through Wall & Underfloor Vents the underfloor void, if left unventilated, can be a breeding ground for mould and a collection point for stagnant – and potentially explosive - gases. However, the problem is easily solved with Beesley & Fildes range of ventilation products – which have the double advantage of being both cheap and easy to install. The modular design of the Combination Airbrick and Cavity Sleeve can be adapted to a variety of situations, while the telescopic Vertical Extension Sleeve extends to reach tricky and cramped areas. The Core Drill Ventilation System prevents the build up of hazardous carbon monoxide from gas appliances. Our Weep Vents, when combined with the products from the Cavity Tray line, not only ventilate wall cavities but also prevent the build up of moisture, saving the homeowner thousands of pounds in repair costs.