The attic, in the minds of most people, is an ordinary, secondary part of the house, causing only indirect interest. But in fact, this is a very important area of any home, and the comfort of the people living in it largely depends on how it is done. Such an element is even more important if a residential attic is equipped in its place.
Features of the
The attic space is mainly an infrastructure facility that completes the structure. There can be placed technological equipment, engineering networks of various types. The temperature difference between the residential and auxiliary parts of the building cannot be more than 4 degrees. Hence it follows that the overlap must be thoroughly insulated and consist of many layers.
To lay the attic floor on wooden beams, you should use:
- roll or board made of boards;
- vapor barrier and ventilation gap in front of the insulation;
- ventilation and vapor barrier after insulation;
- facial floor.
A considerable part of residential buildings and other buildings are constructed from aerated concrete, since it effectively retains heat. The only problem is that slabs made of this material can crack if excessive load is applied to them. Therefore, in any aerated concrete house, a tree turns out to be the optimal material for an attic floor. A prerequisite for success will be thorough impregnation of the material with means that prevent wood from burning and getting wet.
Most often, beams do not exceed 40 cm in height and 20 cm in width, their length ranges from 5 to 15 m
Beam structures are made of metal or wood, using planks, plywood or oriented slabs. Reinforced concrete slabs of various configurations and prefabricated elements with monolithic parts are rarely used. You need to choose a specific type of floor, taking into account:
- seismic hazard;
- span scale;
- number of floors;
- the severity of the vertical load.
In a brick house, the load carried by the walls will be higher. Therefore, the variety of acceptable materials increases, provided that they maintain the stability and stability of the roof. Nevertheless, most developers prefer wooden structures because they are the cheapest and do not require high professional knowledge. The basic requirements for material processing are similar. The most popular are rectangular beams with a thickness of 150x100 mm.
One-piece beam elements are limited by the length of the span, so they cannot be longer than 500 cm. Glued timber is sometimes made three times longer; it is replaced by boards, which, when connected, are placed on the edge. Rounded timber or I-beams are rarely used. In brick buildings, metal beams can be mounted based on:
Such a solution is very attractive, because the metal elements are relatively thin, while mechanically strong and serve for a very long time. In addition, steel does not burn, and with proper processing it will be immune even to corrosion.
The frame house also has its own nuances of creating an attic floor. If a residential attic is equipped above it, there is no need for waterproofing, but it is required to prepare a high-quality vapor barrier. Under attics that are not heated, much more insulating coverings are used, they are positioned in a special way and maximize thermal protection. Under the heated residential premises, the logs and the front floor are separated by a rubber or cork backing to maximize sound insulation.
When two floor layers are used, they also need to be delimited by a soundproofing layer.
An unheated attic in a frame house is equipped with waterproofing from above. It is better to refuse roofing material inside any home, since it is a strong carcinogen.
The attic floor in a house built from vulture panels can be made using the same technology or in the form of a familiar wooden frame. The second option is better in terms of sound insulation qualities, and panels are better in terms of keeping heat. Beams are made from solid timber, dried in special chambers, which is then planed to the nominal size using modern equipment. It is desirable that the slab parts arrive at the construction site already cut according to the project.
The ceilings are made of vulture panels with a thickness of 22.4 cm, although thinner ones - 17.4 cm can be used if the customer wishes. There are a number of subtleties in houses made of foam concrete, in which the attic can rest on structures made of:
- reinforced concrete.
A prerequisite is resistance to constant and intermittent load, with no less important heat retention and dryness, maintaining an optimal level of sound insulation.
The foam blocks themselves can also be used to form an overlap, since they are environmentally safe, they tolerate the effects of fire well and are relatively inexpensive.
The composition of the attic "pie" often includes a film that provides vapor barrier. But foil materials are considered a more perfect solution, which at the same time provide heat retention. Only on top of the vapor barrier can the front finishing layer be attached.
The overlap under the attic, which is at the same time the second floor in the house, necessarily has increased strength and must withstand significant loads. SNIP dictates a certain section of the used beams or the width of the panels, their pitch. The mass of the products themselves and the magnitude of the external load are taken into account.
Sometimes the vault is created from an I-beam, complemented by wooden shelves and an oriented slab wall. In the attic ceilings, the space between the beams is filled with insulation and vapor barrier from the side of the ceiling of the room. Perimeter insulation is usually done with expanded polystyrene.
The rafter system must necessarily be rigid, since shear and expansion forces cannot deform the structure. According to the scheme, this device resembles a triangle. Of all types of wood, conifers of the highest grades with a maximum moisture content of 17% are best suited. It is recommended to avoid workpieces containing knots and cracks. Solid deciduous trees are used for:
The most difficult knot is considered to be a naturally truss truss, which contains, along with rafters, racks, braces and stretch marks. It is required to mount all these parts so that the load does not fall on the walls. According to the rules, only the outer walls can accept this load, but even there the force application vector must be strictly vertical. The distance between the trusses shown in the diagrams and drawings should be exactly the same as follows from the calculations.
The easiest way is to equip the rafter system under a pitched roof, inclined at an angle of 14 - 26 degrees.
In small houses with a span of a maximum of 5 m, the layered type of rafters is used. Such a structure is simultaneously based on both external and internal walls (if any).
Waterproofing and thermal insulation
Heat engineering calculation is reasonably recognized as one of the most difficult moments in the design of residential buildings. At the same time, the requirements of a sanitary and hygienic nature are necessarily taken into account, ensuring the most comfortable living conditions. A typical example of a cold loft pie includes:
- external external walls (in the case of a gable roof equipped with gables);
- the actual overlap of the attic.
Thermal insulation must be done even on a wooden base, not to mention a metal or reinforced concrete.
The variety of acceptable thermal insulation materials is very large, among them there are slabs, rolls and bulk options. Bulk substances are considered the least practical, so it is better to use monolithic structures.
In order to properly insulate the attic, the need for insulation is determined in accordance with the calculated winter temperature. You can find it out in the section of the SNIP on construction climatology, or in the climatic map of a specific region of the country. Ventilated rooms are best insulated with soft or moderately hard heat insulators.
Cold roof waterproofing causes many problems, so no professional will give a universal answer whether it is needed. Consideration should be given to both the material and the level of the roof slope. Under a flat metal roof, it is advisable to place membranes with a high level of diffusion, which reliably block the penetration of snow or raindrops.
Under the slate, a waterproofing layer is not always needed if the surface is intact, but it is still better to mount it in order to avoid flooding in case of violation of the tightness of the coating.
Tips & Tricks
Coniferous beams have the smallest dead weight, which are much cheaper than reinforced concrete products. The lightness of the structure allows it to be mounted without the use of construction cranes and formwork. The maximum permissible moisture content of wood is 20%, and in the case of glued beams, this figure does not exceed 15%. But there is one more limitation: wooden beams are economically justified only with a span length of 420 cm or less, that is, when installing elements on transverse walls. If the length increases, the sections become too large.
The edges of the beams are inserted blindly into the outer walls, the size of the depression is 150-180 mm. The gap from the inner walls to the beams should be 20-30 mm.
For information on how to calculate a wooden floor, see the next video.