The eaves are not the most important part of the roof, but they can be used for a wide range of different purposes. Provided that the calculation is made correctly, the cornice will advantageously emphasize the levels and planes of the slopes, as well as perform a number of useful functions. In modern houses, much attention is paid to such elements even at the design stage. How to make a roof overhang so that it is as practical and aesthetically attractive as possible? To do this, you must first determine its configuration, then the parameters and possibilities for decorative design.
What tasks does the cornice perform?
The proportions of the cornice can change the visual image of the house, increasing or decreasing its expressiveness. Do not discard the stylistic accents characteristic of a particular region. Architectural traditions are being revived today inprivate residential sector, where the owners tend to emphasize the special style of a particular area. As for the tools to achieve this or that image, both the size and the shape of the cornice overhang will be important. The photo of the roof presented above, for example, demonstrates the advantages of a massive overhang in relation to a small house. Visually, the design becomes lower and wider, which adds to the perception of the building a sense of reliability and good quality.
Functional tasks will mainly be expressed through design possibilities. In part of the eaves, it is possible to lay communications, arrange outlets for ventilation and a chimney, and mount other engineering and technological channels. The width of the overhang will also affect the microclimatic properties of the house. The fact is that the long overhang of the cornice obscures the window, absorbing thermal energy. If we are talking about a metal roof, then the accumulation will occur very quickly, passively warming up the entire roof covering. This effect can be used in different ways in winter and summer.
Roof cornice installation
The overhang as such is a structural unit in which the slope and the horizontal overlap meet. As the latter, only a cornice strip can act, emerging from the attachment point of the Mauerlat to the outer wall. The interface configurations of the parts of the truss system may differ, therefore there cannot be a single principle for determining the elements of this node. One way or another, in any design, roofing will play an important role.a cake that forms an overhang. This is the part of the slope that goes beyond the level of the outer wall horizontally to the side, and in some cases it may fall significantly below the level of the attic floor horizontally.
Now it's time to move on to the materials of the cornice overhangs. The device of the roof is determined by the combination of the supporting base of the slope with wooden (or thin metal) beams, sheathing and outer covering. The outer layer can be represented by a soft roof, corrugated board, tiles, etc. In essence, this combination will provide an external protective frame for the eaves. The cornice itself is formed by the lower bar, which will connect the outer wall and the slope. It is also more often made of wood, but plastic is also found.
Varieties of cornice overhang
There are several options for the execution of the roofing cornice, which differ in design and functionality. The most common is the usual closed cornice, which provides for a slope of average slope and overhang length and a horizontal bar that forms a soffit. A simpler design does without a bar at all. Also, an overhang is directed along the inclined side, but there are no covers on the underside - an open structure is obtained, which has significant pros and cons. Firstly, this is a typical eaves overhang of a seam roof with metal decking. The coating is rather flimsy and non-functional, so with such a slope it makes no sense to arrange cornice closed boxes. Secondly, this solution requires a higherdegree of insulation at the point of convergence of the Mauerlat and the roof.
A special group of eaves overhangs are brick structures. Instead of a wooden plank, the lower part of the overhang in this case will be covered with brick (or masonry). This option is used infrequently, but it can be used to create original facade designs.
Features of cornices on a soft roof
This type of roofing is one of the most problematic in the sense that the material is heavy and gives a significant load on the slope. Accordingly, one should focus on strengthening the structure from below and from the side. The optimal device for a cornice overhang for a soft roof may include filing from a crate using wooden bars and metal fasteners. The power base will be provided with anchors along the entire length of the batten attachment, as well as metal corners and mounting plates that will act as additional fixators.
Features of flat roof eaves
In this case, the design is simplified, since there is no need to create an inclined angle of the slope with the corresponding designs from the bottom. That is, there will be support and sheathing from below, but it is much easier to implement it horizontally. In the simplest version, the cornice overhang of a flat roof can be designed as a combination of a straight slope and a ceiling. Roughly speaking, the attic floor will take off to the side beyond the boundaries of the outer wall. The roofing pie on the ramp will also come out on the upper level. Then it remains only to closeboth designs are flanked by plastic or wood cladding. The result is a fairly functional box of the correct shape.
Eaves eaves parameters
As before, and in our time, the best way to calculate the width of the cornice is the angle of the overhang. It can be different depending on the slope of the slope. On average, Russian houses are designed with roofs whose slope varies from 30 to 45 degrees. What would be the best flight? There is a special regulation that determines the size range of the cornice overhang in width from 10 to 70 cm. Further, everything will depend on the type of roofing material. So, the shortest cornices are used on rolled metal roofs - from 10 cm. Galvanized steel sheets allow you to arrange overhangs with a minimum length of 15 cm. And wavy asbestos concrete panels are made with a width of 25 cm or more.
Eave installation
Installation of this item mostly comes down to backboarding with wood planks, plastic panels or siding. The main thing is not to use metal in this part, since the removal of condensate through the spotlights creates favorable conditions for corrosion. How to install a roof eaves? When the contours of the ramp and Mauerlat have been determined and their designs are ready, you can proceed with the installation of the supporting crate for filing. It is advisable to use a small-format beam. The supporting parts are fixed with screws to the wall or Mauerlat - as the design allows. Along the lines of the bearing slats, a number of small slats are attached with indents of approximately 20-30see At the final stage, sheathing is carried out over the entire area on the back of the eaves - with plastic or wooden clapboard.
Eaves ventilation system
Even at the stage of developing the cornice scheme, it will not be superfluous to determine the method of implementing the ventilation system. Air circulation in the under-roof space is necessary to combat dampness, which is harmful to the wooden truss system. The simplest way to install ventilation in the eaves of the roof is to initially use perforated plastic panels for sheathing. They are specially designed as soffits under the eaves for the organization of the air duct. If wooden planks are used, then you must first leave room for gaps. Sometimes for such purposes they simply maintain a space between the planks of the skin of a few millimeters. Actually, it is enough that the overhang box is not completely sealed.
Conclusion
Cornice is a significant and responsible part of the roof, but very delicate in execution. Much in the implementation of this element will depend on the neighboring materials of construction. For example, the cornice overhang of a soft roof cannot be mounted without taking into account the characteristics of the coating, which often limit the masters in the choice of technical solutions. For such a roof, it is better to turn to special additional soffits that will cope with the loads from a heavy roof and provide the necessary space for possible laying communications in the box.
Ifthe slope is covered with light corrugated board, then you can do without capital support with the formation of the skin. It is enough to take care of the mechanical protection of the assembly and ensure free air circulation in the butt joints. But, on the other hand, the absence of a mounting box in itself excludes a number of design possibilities, also associated with the installation of gutter elements and snow retainers. For this reason, counting on the long-term operation of the roof, it is worth considering the role of the eaves from the point of view of various aspects of the application.
