Ventilated Roofing

M3 and L3 Ventilated Systems

M3 SystemIn response to ventilation/condensation and wind-loading issues, in 1994 we developed our own ventilated Batten Roll and Standing Seam systems for use with all of the hard metals. With this system, the air-permeable joints keep internal and external air pressure in equilibrium, thus minimising the effects of wind. In traditional systems this state does not exist and when external pressure is lower than internal pressure upward deflection occurs, which can cause metal fatigue, wind rattle or disengagement of panels.


Zinc roofingBecause joints perform as ventilators, construction can be either warm roof or cold roof; given in the latter case an air-permeable fixing surface is provided e.g. square edge boarding (sarking) Unlike conventional eaves ventilation where air has to move across the full roof, decreasing in efficiency as the roof pitch flattens; with our ventilated system air only has to move across half the width of a panel. High internal air pressure at the eaves is also eliminated.

Capillary/Thermal Pumping

L3 SystemAir pressure in equilibrium and absence of tightly formed seams, eliminates this risk especially on low roof pitches.

Thermal Expansion and Contraction

Because of the low wind-load effect, panels do not require restraint at the eaves therefore long panels are free to move.