Protected Open Ridge System

At Tegral, we understand the importance of ventilation in agricultural buildings and the negative impact that poorly ventilated buildings can have on livestock health. With this in mind, choosing products and systems that provide maximum airflow is essential to creating the best possible environment for your livestock whilst also mazimising the return on investment for you.

Our Protected Open Ridge System is the most effective way of naturally providing outlet ventilation in an agricultural building whilst also having the added advantage of providing more light than traditional systems.The polycarbonate strip lets more natural light into the building avoiding hot spots also.



The critical factor to efficient open ridge ventilation is the air gap (marked y on the diagram). The clear width of this air gap relates to the number of animals that will be kept inside the building. We recommend professional advice is sought during construction in order to establish the optimum air space required.

To meet the requirements of HSG 33, the gap between the purlins at the apex of the roof should be no more than 300mm. For this reason we show two purlins on each side of the apex. The ventilation gap (y) is therefore limited to 200mm.

In a protected open ridge system the ridge unit is bridged at 750mm centres by galvanised metal straps manufactured to suit the pitch of the roof. The straps are fixed at an angle of 5° from the horizontal. The 6mm polycarbonate is then bolted to the straps along the length of the ridge to form a cover. This cover must be positioned 20mm minimum below the top of the upstands of the ridge units, and the total gap between the cover and the open ridge (x) is such that: 



If you have any queries about this section or any of the information attached please feel free to phone the Tegral Technical Support Department on +353 (0)59 863 1316 or email

Tegral Building Products is independently certified as meeting requirements of ISO 9001 (quality), ISO 14001 (environment), OHSAS 18001 (safety) and BES 6001 (responsible sourcing).