The Science of Roofing

Roofing is not all about muscle — at least it shouldn't be. Many roofing skills date back hundreds of years: fixing slates and tiles, fashioning leadwork, positioning timbers. However, modern times means new materials and taking into account the different ways people use buildings and the consequential design considerations.

Energy conservation

Older houses that were originally heated by open fires are being modified to use different fuels. Draughty doors and windows are being replaced by air-tight uPVC frames and thermal insulation is being added where possible. All of these things help reduce heating costs but these actions can also cause high levels of mositure in the dwelling, not least because we all now have indoor bathrooms and shower rooms.

Moisture carrying warm air must be allowed to ventilate in a controlled fashion otherwise the moisture seeps into the structure in the form of interstitial condendsation. This can cause damaged to plaster, timber to rot and, because water conducts heat, loss of thermal insulation.

Warm air rises, so the biggest problems tend to occur in the roof spaces. The diagram below shows how to prevent mosture build up in the roof space with the correct airflow while still maintaining a high level of thermal insulation.