How To Ventilate Roof Space

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

How to ventilate roof space.

Roof vents are for warmer climates. If your roof peak runs parallel to the street put them on the backside where they ll be less prominent. Ventilation can be accomplished using various products and techniques. Vent the roof deck.

Exhaust vents which are located near or on the ridge line of the roof and allow air to leave the attic. In extremes of cold still air condensation overload may occur even where the roof space ventilation complies with the guidance given in bs 5250. Different forms of high and low level ventilation are used as well apart from the soffit vents and ridge vents pictured. A double polypropylene cavity batten approximately 13 000 mm2 nfa fixed above every purlin can be used to ventilate the attic space up the roof slope but the actual air movement is very much dependent other factors of the building design.

Before we explore how to ventilate an attic space it is prudent to understand how much ventilation is needed. That said air resistance and interference such as vent grates reduces the area of true ventilation. These roof types are the most common type found in ireland. In older properties we must accept that air leakage happens and adequately ventilate the roof space to prevent harmful condensation forming.

Fairly simple stuff fresh air in old stale air out. Roof ventilation this picture represents what is considered to be the best way to ventilate a roof space. To ventilate a roof space adequately the type of roof structure must first be identified. The first roof type to be discussed will be pitched roofs.

Place all the roof vents on the same side of the roof. Too many people believe the importance of roof ventilation is to increase energy efficiency during the summer. Intake vents located at the lowest part of the roof under the eaves allow cool. In other words the entire vent opening doesn t count as vented space.

Within this category of roof those where the ceiling follows the roof line and those where the ceiling is formed using ceiling joists. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca.