WIRRAL ROOFER

The UK Building Regulations now mandate that, on all new roofs, a mechanically fixed ridge tile system is installed. This means if you are having your old roof completely replaced the ridge tiles must be mechanically fixed. On roof repair jobs, where only parts of the roof are being refurbished, you have a choice as to whether to stick with the conventional method of bedding ridge tiles in mortar or opting for the mechanically fixed system.

Though not mandatory on roof refurbishments it is still a good idea to consider having a dry ridge system fitted because it enables proper moisture vapour release to take place. When older properties were first constructed internal mositure was not a problem because of natural ventilation via chimneys and naturally drafty windows. In homes where upgrades have significantly reduced passive ventilation moisture generated by cooking and washing can cause rot and mould growth (see Interstitial Condensation).

This regulation has been introduced in recognition of the fact that average wind speeds in the UK are increasing due to the more eratic weather conditions brought about by global warming.

Though the mechanically fixed system costs a little more, it has two advantages: (1) it contributes to holding the entire slate or tile roof in position and (2) it provides a vapour permeable method to prevent damaging moisture build up in the roof (see 'Vapour Permeability').

British Standard BS 8216:2018 sets out the requirements for fixing security, weather-tightness, durability and where required, ventilation, of dry ridge systems.