Arrangement of the roof is completed by laying the roofing and installing the ridge. This is a crucial stage, since a whole complex of technical and protective qualities of the house depends on it. The most beneficial would be the creation of a ventilated ridge, which will provide ventilation of the under-roof space, exclude the penetration and accumulation of moisture in it.
Benefits of ridge ventilation
Problems of ventilation in the roof area can be solved in many ways. A huge range of structures that allow you to organize a vertical air duct through channels from the premises to the roof, makes it possible to provide effective ventilation for any type of roof. For common metal tile and profile coatings, a ventilated seam ridge is more often used, which has a number of operational advantages:
- Tightness. The closed design virtually eliminates the possibility of penetration of dirt and insects into the underlayniche.
- Reliability. The same vented ridge pitched flanged roofs support the basic functions of a roof covering, providing protection from rain, wind and physical impacts.
- Effective ventilation. The main task of this element, which is solved by a special gap. It is performed in such a way that at the same time a barrier is provided against external influences and at the same time the circulation of air flows is maintained.
- Mechanical resistance. The skate can be constructed from different materials, but usually a high-strength metal-plastic base is used.
- You can use the vent-horse both on classic gable roofs and as part of more complex structures such as hip roofs.
Air-exchange skating device
The ridge itself is a truss assembly located at the top of the roof. It is formed as a result of bringing together two slopes, at least, bearing beams and elements of the crate are mated. The top layer of roofing is not joined. A feature of the ventilated ridge device is the preservation of the gap between the pitched surfaces. Gaps through which air escapes are formed continuously or alternately along the entire line of the ridge. But the following question arises: how is the reliability and tightness maintained with such a design? These and other protective qualities are guaranteed by a triangular patch panel that closes the seam strictly at the top and on the sides. Seemingly,a zigzag path is formed, along which air can escape only with great difficulty. And yet this system works quite effectively.
The principle of operation of the structure
In order for the air currents to stably pass through the ventilation duct system (rising and descending), a draft of the appropriate strength is required. To create it, two conditions must be met:
- Natural convention. The law of physics, which will apply to any under-roof spaces, where, in principle, there is warm humidified air. Heated streams tend to outward, being replaced by cold air. This creates the basic condition for the ventilated ridge to work as an effective air exchange and ventilation system.
- Sufficient air flow. In an attic completely sealed at the lower and middle levels, there is physically no opportunity to replace warm air, respectively, the circulation will not work. You can correct the situation with the help of perforated spotlights in the cornice system. They will become sources of cold air coming from the side of the lower overhangs. Further, the air is heated, humidified and directed upwards, passing through the holes of the ridge.
Technical options
There are two approaches to performing a vent skate. The first involves the use of an aerator. This is a plastic overlay with factory perforation, which is mounted on the node of the convergence of two slopes, fixed with hardware and covered with roofing material. The average length of the aerator is 1.5-2 m, so several segments may be required per roof. They are interconnected by built-in locks according to the hook principle.
The second method involves the self-assembly of a ventilated ridge without the use of an aerator. The design, on the one hand, is simplified, and on the other hand, it requires increased attention to detail from the performer, since the ridge is also a critical element of the truss base. At the point of convergence of the slopes, in this case, a triangular crate-overlay of bars is arranged. Gaps are left between its elements, which are also covered with a layer of roofing from above.
Aerator installation
The central part of the roof aerator must be installed strictly on the ridge beam so that both sides of the slopes are captured. You should not be afraid of a dense lining on the roof on the outgoing sides, since the ventilation channels in the aerator are built-in and do not imply leaving additional holes. Difficulty can arise only when installing a ventilated ridge for a seam roof, which has a corrugated coating. Accordingly, unwanted eyelets will be left, which in the future will have to be separately sealed with adhesive waterproof compounds.
Making a vent-ridge with your own hands
This method is applied to pitched knots with a gap of about 30-50 mm. This will be the ventilation gap for the roof duct. The task of the master is to raise the ridge lining by about the same 50 mm to provide a side channel for the circulation of flows, which in practice will direct air down the slopes, and will not allow dirt and precipitation to pass into the under-roof niche. A ventilated ridge is installed on this type of roof using bars similar to a standard crate. A load-bearing wooden base is mounted along the entire length of the ridge, on which a metal protective casing is laid, and then the roof.
What else to consider when installing a vent-ridge?
Among the additional devices, power, filtration and decorative elements can be provided. The reinforcement is created by the inclusion of rear mounting strips and metal profiles, which act as stiffeners from the side of the truss structure. Filtration is carried out in aerators in a natural way, and when installed independently, it can be implemented with membrane vapor-permeable linings and seals in the crate. As for the decorative design, the ventilated ridge is usually decorated with non-standard roof overlays of the original form. These can be inserts with panels matching the color of the profiles or tiling, but with an eye-catching texture.
Conclusion
The choice of vent-ridge installation technique depends on the characteristics of the roof and its components. For example, for flange-type metal sheet coatings, it is quite possible to apply the lathing technology. If you plan to install a ventilatedfad for a soft roof, it is better to turn to ready-made solutions with aerators. Such devices well protect the under-roof space from moisture and dirt, and also effectively support the load-bearing function in the rafter system. And in both cases, it is important not to forget about sealing joints that are not related to ventilation as such.
