Depending on the type and geometry of the roof, certain materials are selected for its construction. Roofs are: flat (industrial buildings, baths) and pitched (residential buildings and other buildings). Depending on the number of slopes, they are divided into: single-sided (section in the form of a trapezoid), double-sided (have the shape of a triangle), half-hip, hip (consist of several slopes), hipped (looks like a pyramid), attic. The number of slopes, the slope of the roof, the presence of an attic - all this affects the choice of load-bearing and self-supporting elements of the roof structure.
Support structures
One of the most important parts of any roof is the support. Rafter legs or trusses can usually be supported on:
- top crown in log houses;
- string board in frame buildings;
- Mauerlat in stone buildings;
- metal beams, brackets.
Mauerlat is a structural element of the roof, which is a beam (usually with a section of 100 × 100, 150 × 150 cm). It attaches around the perimeter.walls in those places where rafters or trusses will be supported. Mauerlat is necessary for uniform load distribution and strong fastening of load-bearing structures. Of course, you can do without it, but it provides additional rigidity to the entire roof.
If the house is being built from timber, then the upper crown is used as a support. It has all the necessary fasteners, so load-bearing structures are immediately mounted on it. Frame buildings are assembled from wooden panels. They consist of vertical planks held in place by a strapping element. It is to him that the future roof is attached.
If it is made of metal trusses or rafters, then a channel or an I-beam will serve as a support. They can be attached to stone walls with anchors.
Rafter system
The rafter system is a roof element that bears the load of the entire roofing "pie" (covering, lathing, insulation, finishing). Most often, when erecting roofs, rafter legs are used, which are: hanging and inclined.
Hanging structures are based on two points located on the load-bearing walls. In such a system, the walls experience horizontal loads, which are reduced by metal or wooden puffs. Mansard and attic roofs are mounted in this way.
Slanted rafters are suitable for buildings inside which there is an intermediate support (internal wall, column or beam). The other end is located on the outer walls. These mounting optionsrafters can be combined with each other: choose inclined ones if there are internal supports, and use hanging ones if they are not.
Also rafters can be made of metal. For large-span buildings, it is possible to use such structures under the skates. It should be remembered that the junction of metal with wood must be protected by special means and insulating materials. This is necessary so that the wooden elements do not rot from the condensation that forms on the metal parts.
Truss trusses
Very important and reliable elements of the roof of the building - roof trusses. They are: wooden, metal (welded and prefabricated), reinforced concrete. The choice of material depends on the length of the span of the building and the loads experienced. A farm is a set of parts (racks, braces, puffs) that are fastened together.
The most popular are wooden structures, which are lightweight, durable, affordable. To connect their parts, a cut, bolts, nails, MZP are used. Metal and reinforced concrete trusses are usually used in large-span buildings. They are more expensive, durable and heavy. Metal elements are fastened with bolts and welding.
In modern construction, wooden trusses connected with metal toothed plates (MZP) are in great demand. They have a large number of advantages:
- speed up installation as the trusses are delivered to the job site ready-made (manufactured by hydraulicpress);
- make finishing easier with their lower waistband. The crate is attached to it, and then the sheathing itself;
- allow span up to 30 m;
- simplifies the assembly of complex roofs (hip, mansard, attic).
Additional elements
In order for the roofing to look neat, beautiful and not require constant repairs, it is necessary to use additional elements for the roof. They are needed to preserve the integrity of the material, as well as to protect (from moisture, dust) and decorate structures. Most often, such products are made of galvanized steel. However, they can be the same color as the roofing material.
Most popular roof element names:
- Eaves plank. Forms a joint between the cornice and the first row of covering.
- Front plank. Closes the junction of horizontal structures with vertical surfaces.
- Ridge plate. Hides the hole at the highest point of the roof.
- Valley (for internal and external corners). Closes the junction of intersecting planes.
- Eave rail. Prevents precipitation, dust and dirt from getting through the eaves.
- Adjacency bar. Protects the connection area of the coating with parapets, pipes, chimneys.
- Snow guard. Prevents snow from falling off the roof.
- False pipe. It is a smooth sheet that decorates the chimney box.
- Lightning rod and grounding. Protect the building from lightning.
- Window tide. Closes the jointsthe perimeter of window openings so that moisture does not penetrate through them.
- Plugs for gutters, skates, etc.
- Small parts (various seals, gaskets, etc.).
- Decorative products (wind indicators, spiers, chimney caps, ventilation, parapets).
Dashers and aerators
The main task of both elements is to ventilate the space inside the roof. This is necessary so that the insulation does not rot. The minimum size of dormer windows is 1.2 × 0.8 m (with two wings). Balconies can be attached to large-span structures. The spacing of the openings is at least 800 mm. Their total width should not exceed half the length of the building.
Dormers - roof elements that are installed in slopes with a slope of 35 degrees. Outwardly, they resemble separate structures that have their own walls, roof and drainage system.
As for the aerators, they can work according to two principles: to create draft in the pipe or to be included in the work due to different pressures inside the roof and on the street. Without these small elements, the air will not be able to circulate normally in the inter-roof space. As a result of their work, structures do not freeze, do not thaw, and are not covered with moisture. This prolongs their service life.
According to the method of ventilation, aerators are divided into point and continuous. The latter are located along the length of the ridge, and outwardly they are invisible. Spot elements are installed on slopes (with an indent from the top of the roof no more than 600 mm) or on a ridge.
Guttersystem
Another important element of the roof of the building is the drainage system. It consists of the following components:
- Gutters. With their help, water flows in the right directions.
- Tube. Thanks to them, precipitation enters the drainage system.
- Funnel. Through them, water enters the pipes.
- Stubs. Used to restrict flow.
- Fasteners. Pipes are fastened with clamps, and gutters with brackets.
Depending on the material, gutters are plastic and metal. Plastic products are considered the most popular today. They are lightweight, attractive, easy to install and long lasting. Metal gutters are also in demand. Manufactured from galvanized steel with polymer coating. The main disadvantage of such products is low resistance to mechanical stress (scratches, shock loads).
Roofing material
Roof coverings are: rolled (roofing material), sheet (metal tiles) and piece (ceramic and flexible tiles). Roll materials are inexpensive, long-lasting and easy to install. As a basis for them, a solid flooring is used, which makes the surface as even as possible. To fix the material, bituminous mastic is used, heated by a burner or blowtorch. Products are stacked in several layers, coming with an offset.
Sheet material can become an element of a wooden roof or any other. ToThis group includes: metal tiles and corrugated board. Under them there should be a crate, the step of which depends on the wavelength of the product (usually 300-400 mm). Decking is in great demand due to its low cost, ease of installation and attractive appearance. Both materials can be fastened with self-tapping screws with or without seam seams. The first option is considered more reliable, as the rigidity of the roof increases.
Ceramic tiles are beautiful, durable, but very heavy and expensive. That is why it does not occur so often. Another piece material - flexible tiles - is more popular today. It is made in different colors, as a result of which the coating looks voluminous and very solid. If it starts to rain, the coating will drown out the impact of drops (which cannot be said about the metal tile).
Protective films
If the roof will be insulated, it is necessary to protect the thermal insulation with steam and windproof films. Waterproofing will have to be laid under the sheet material. All these films will protect against moisture, condensation and decay. Waterproofing and windproof coatings have been combined today into one product. Let's get to know each of them better.
Waterproofing laid under the cover protects against condensation. It is also used when installing ventilation - it does not allow water to penetrate into the system. Waterproofing well passes air, but does not let moisture through itself. If condensation accumulates inside the roof, then over time, the supporting structures will begin to rot or rust. Filmis attached to the roof truss element, after which the counter-battens and the crate are nailed. Don't pull it too tight - it should sag a little.
Vapour barrier is used only in insulated roofs. It closes the thermal insulation from the inside of the room. It can be located in a horizontal and vertical position (for example, in attics). If this film is not laid, the insulation will get wet and stop retaining heat normally. Mounted with small nails or a construction stapler. A gap of 100 mm is laid between the vapor barrier and thermal insulation.
Insulation
There are a number of requirements for such an important element of the roof as thermal insulation. It should be lightweight, environmentally friendly, durable and fire resistant. It is very important to protect the insulation from moisture so that it does not lose its properties.
Most popular thermal insulation materials:
- Styrofoam. Lightweight, durable and best suited for flat roofs.
- Polyurethane foam. Keeps warm well, durable and lightweight.
- Glass wool. It is made from melted glass or its waste. The material absorbs sounds well, does not absorb moisture, is not afraid of frost and does not wrinkle during operation.
- Mineral wool. The structure of its fibers can be different: layered, spatial, corrugated or vertically layered. The material retains heat well, absorbs sounds, is not afraid of moisture, rodents and temperature changes.
Interior decoration
There are several options for finishing the roof from the inside. Usually these works are done in attics or in warm attics. As a sheathing, you can use: drywall, lining, plywood or OSB-plates.
Finishing with drywall begins with slopes and gables, after which they move to the ceiling. A crate going in increments of 1 m will help facilitate the work. Additional bars are nailed horizontally (step 300-500 mm). After that, drywall is fastened with self-tapping screws to the prepared surface. It is leveled with putty (in the area of holes) and primed.
A lining can be a good element of the roof. It is cut and attached to the crate with nails. It is necessary to constantly check the evenness of the surface with a level. As soon as the last element is fixed, the lining is varnished.
Another option for interior decoration is the use of plywood. It well levels the surface, after which it can be covered with paint or wallpaper. It is best to use moisture-resistant plywood as sheathing so that it does not suffer from accidental leakage. The material is attached to the crate with nails or self-tapping screws. Work begins with gables and slopes, and then moves on to the ceiling.
OSB-plate can be attached directly to rafters and trusses (no additional batten required). Before finishing, the surface is leveled, and then the sheet is fastened with screws. Additional leveling will not be needed if the truss structures are made from sanded board.
Attic device
Attic canbe completely different, but the main elements of the roof will remain almost the same. In addition, their arsenal is no different from ordinary roofs.
Depending on the number of slopes, the attic is divided into:
- Shed. Such a building has one wall high and the other low. At the same time, both of them can go at an angle. It is possible to mount the same walls with a shed truss.
- Dual slope. Such lofts are very common because of their reliability and easy installation.
- Broken lines. This option is used if a small building needs to be built on.
- Hip and half hip. Such roofs are in demand due to more rational use of space.
- Conical, pyramidal and domed. They are found in polygonal or rounded buildings. Attics look beautiful, but difficult to build.
It may seem that the roof does not have many components. But it is worth taking a closer look to be convinced of the opposite. At the same time, all elements perform certain functions, which makes each of them irreplaceable.
