Eaves Ventilation Systems

Roof Ventilation - The importance of getting it correct.

Homes these days are becoming more airtight and better insulated, and as a consequence, warm, moist air generated within living spaces passes through the ceiling and migrates into the cold roof space or void. The ability of the air to to hold moisture reduces as it cools, so it deposits the moisture onto cold surfaces in the form of condensation. If this happens, then the results can be far from ideal with the build up of moisture, causing possible rotting in timber, mould issues (health risk), and the staining of paintwork on internal walls and ceilings.

 


 

The majority of homes are built with a pitched roof, and the problem can be simple to eliminate, just by ensuring there is enough ventilation in the roof space. There are a number of ways to achieve this:-

Tradition dictates that low-level eaves-to-eaves ventilation be used, where a gap is created between the insulation and the roof underlay at the eaves. High-level ventilation at or near the ridge (e.g. Ventilated Dry Ridge System) is an extremely effective form of passive roof ventilation, effective in all weather conditions.A combination of low & high-level ventilation provides the most secure solution of achieving good roof ventilation.

Roll Out Rafter Tray

Air flow detail through the Over Fascia Vent

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