A problem a lot of buildings suffer in the cooler months of the year is the presence of condensation within roof spaces particularly upon the underside of traditional reinforced bitumen roofing felts. This has become more prevalent in recent years due to various factors including;

Modern living habits generating greater levels of water vapour within the air as a result of more regular bathing/showering, tumble drying etc.

Increasing air temperatures within our buildings thus allowing the air to hold more water vapour (i.e. warm air holds more water vapour than cold air).

A significant reduction of natural ventilation through our buildings due to our preference for modern double glazed draught proof windows and doors and the removal of chimneys; whilst the presence of traditional reinforced bitumen roofing felts (generally predating the 1990s) above our roof spaces also prevents natural ventilation through these areas.

The increasing level of insulation laid above our ceilings is creating colder roof spaces.

The condensation is caused by the increased moisture levels within our buildings which can only escape into our roof spaces (due to the presence of our double glazed draught proof windows and doors and blocked chimneys); which when insulated (by the ever increasing requirements of modern building standards) leads to a colder environment within the roof space (less able to hold moisture) which results in the air depositing its moisture upon the cold underside of our roofs.

The problem will inevitably continue and possibly become even more widespread as a result of the colder winter temperatures we are experiencing along with our need to improve the thermal and energy efficiencies of our buildings. The condensation in extreme cases can reduce the effectiveness of roof insulation, cause damage to decorations (with staining and mould growth upon the underside of ceilings) and most significantly allow the onset of wet and dry rots, woodworm and other beetle infestations which can substantially impair the integrity of the roof structure.

In most cases, the extent of condensation can be relatively easily reduced by the introduction/improvement of ventilation through the roof space.

We recommend that you make time to inspect your roof spaces and the underside of traditional reinforced bitumen roofing felts for the presence of condensation. If you are experiencing such problems; you are advised to consider the implementation of remedial measures. If you require further advice please do not hesitate to contact us for a free preliminary discussion.


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