The loft is a unique and unusual environment

The loft is a very valuable part of a house, and can form up to 50% of the floor space. Many homeowners however see the loft as a dark and dingy place that they don’t want to go into, full of dusty insulation. But it does not need to be like that, as a boarded loft can become a beneficial useable space. Firstly though, it’s necessary to know about the different types of lofts, and to prevent the risk of damp.

Lofts are characterised as either “cold” or “warm”. A cold loft is where heat is kept in the house and out of the loft by insulation placed on the floor of the loft, and where there are gaps in the eaves under the roof for ventilation to take away any moisture. This is the most common type of loft in Britain, and building regulations in the UK specify that there must be at least 270mm (11”) of insulation, if mineral wool insulation products are used.

A warm loft is a room in the roof that is a habitable part of the property and has insulation in the rafters under the roof.

The term “cold loft” is however somewhat misleading. These lofts can indeed be very cold, with the temperature sometimes dropping below freezing in the winter, but as there is no insulation under the roof, they also trap heat in the summer, and can become very warm. There are instances of lofts exceeding 40 degrees Celsius in a British summer.

Condensation is a particular problem that needs to be avoided in lofts, as the damp will damage any items stored in the loft and cause the wood to rot. In cold lofts, it is essential to have a good flow of air from eave to eave on either side of the house to counteract this. Something that is often overlooked is the risk of condensation forming on the underside of loft boards. LoftZone commissioned a report from the Buildings Research Establishment that showed that if boards were placed directly above the required 270mm of loft insulation, then there was a very high risk of the moist air cooling as it rose through the insulation and then condensing on the underside of the board, forming damp that will then rot the board and make the insulation wet. (This has a similar effect to interstitial condensation). It is therefore imperative that there is an air-gap between the top of the insulation and the underside of the board, so that the ventilation from the eaves can remove any moist air, and that is why the LoftZone StoreFloor product is designed to provide this air gap. Homeowners and buildings professionals are warned not to use solutions that do not provide this.

Extremes of Temperature

UK lofts commonly reach freezing temperatures in winter and over 40C (or 100F) in a hot summer. These wide temperature swings mean any construction in a loft must be designed to safely cope.

LoftZone StoreFloor has been rigourously tested in extreme temperature swing cycles and is the only raised floor on the market that is specifically designed with these conditions in mind. Many plastics will degrade quickly in these conditions, but the polymers used in StoreFloor supports are designed with this in mind.