The information about which will be discussed in this chapter, of course, is well known to any competent architect and builder. But we believe that at least in general terms to understand and know it should and the customer at home - the future owner, the one for whom the house is built. Any mistakes made in the project, or received during the construction process, will become a problem in the process of operating the house. Therefore, additional control by the customer when solving the following requirements is necessary.
So what should you think about, what is it worth to understand and know if you are building a house for your family?
Your future home should provide:
You should also decide whether you are building a house for seasonal or permanent residence, whether the speed of construction is important for you (whether it is necessary to apply the technologies of prefabricated houses).
It is also important to make a decision about the project at home - buy ready standard project or order an individual.
And now about all the above listed in more detail.
Thermal protection (thermal insulation) at home
The main task of heat protection is to ensure the comfort of living in the house. Comfort in the room depends on:
Temperatures of internal air (optimum 20 - 220С);
Temperatures of the internal surfaces of the walls enclosing the room (minimum 16 - 180С, otherwise there is a feeling of draft);
Thermal inertia of walls enclosing the room (heat accumulation, walls, with low thermal inertia - rapid heating, rapid cooling).
Temperature of the floor surface (optimally 22 - 240C);
Relative air humidity in the room (normally 50 - 60%,<40% - сухость слизистой оболочки, >60% - a greenhouse climate, high humidity)
The movement of air (maximum 0.2 m / s,\u003e 0.2 m / s - a feeling of draft).
To provide heat protection at home, it is necessary to take into account a number of factors that are significantly different for winter and summer.
Winter thermal protection
1. Thermal insulation of enclosing structures (walls, ceilings, windows, exterior doors)
2. Thermal inertia of the enclosing structures (walls, ceilings / floors). For human comfort near the walls, as well as preventing moisture condensation, the thermal inertia of the structures is very important
3. Location of individual layers in multi-layered enclosing structures. The correct sequence of layers "from the inside to the outside" is especially important. Otherwise, condensation may form inside the structure.
5. The ratio of the area of windows and other translucent structures to the surface area of the outer enclosing structures of the building (windows are often weak points)
6. Geographical location of the house (latitude, altitude, cloudiness conditions, fog frequency)
7. Orientation of windows and other translucent structures to the sides of the world. Solar heat inputs are different depending on the orientation.
8. Air exchange (opening of windows and outside doors, air permeability of windows and doors due to seams and leaks, forced air exchange with or without heat recovery).
Summer heat protection
1. Sun protection devices (awnings, sunshades, blinds)
2. Accumulation of heat in enclosing structures (walls, ceilings / floors). Sufficient heat capacity of structures is expressed in a favorable ratio of temperature amplitudes on their external and internal surfaces
3. The location of individual layers in multi-layered enclosing structures - the drying of structures in the summer months (the period of evaporation of moisture), thermal inertia and a phase shift of temperature fluctuations on the surface of the structure
4. The total energy transmittance of windows and other translucent structures (external doors with glazing, winter gardens, etc.)
5. The ratio of the area of windows and other translucent structures to the surface area of the outer enclosing structures of the building 6. The geographical position of the house (latitude, height above sea level, cloud conditions)
7. Orientation of windows and other translucent structures on the sides of the world (different sunscreens depending on orientation)
8. Ventilation capacity (forced ventilation, by opening windows)
9. Painting the exterior surfaces of walls (light surfaces reflect heat rays, dark surfaces absorb heat rays).
Heat losses in a room are determined by two factors:
Transmission losses that are added up by the heat flows that the room gives through walls, windows, doors, ceiling and floor.
Ventilation losses, by which is meant the amount of heat necessary to heat cold air into the room, penetrating through the leakage of the window and as a result of ventilation.
In Russia, for the evaluation of the thermal protection characteristics of structures, the resistance to the heat transfer Ro (m² ° C / W) is taken, the inverse of the thermal conductivity coefficient k, which is adopted in DIN standards. The greater the resistance to heat transfer of the structure, the better its thermal insulation ability. Humidifying impairs the heat-insulating ability.
The coefficient of thermal conductivity k characterizes the amount of heat in watts (W) that passes through 1m² of construction with a difference in temperature on both sides of one degree on the Kelvin scale (K), unit of measurement W / m² K. The smaller the value of k, the less heat transfer through the structure i.e. above its insulating properties.
Unfortunately, a simple recalculation of k in Ro (k = 1 / Ro) is not entirely correct due to the difference in measurement techniques in Russia and other countries. However, if the products are certified, then the manufacturer must provide the customer with the heat transfer resistance index.
The temperature of the surface of the enclosing structure, which is turned into the interior of the room, depends on the value of the Ro exponents. With a large temperature difference, the heat radiates towards the cold surface.
Resistance to heat transfer of enclosing structures is normalized SNiP II-3-79 * "Building heat engineering". In addition to all-Russian normative documents There are also local, in which certain requirements for the region can be tightened.
The feeling of comfort in the room depends on:
Wall surface temperatures.
Whether a person feels comfortable in the room depends, along with the factors already mentioned, also on the thermal radiation of the surfaces of the enclosing structures. We feel comfortable, in terms of temperature, if the internal surfaces of the walls in winter are no more than 3 ° C below, and in the summer no more than 3 ° C above the air temperature in the room. The temperature of the surface of the walls depends on their resistance to heat transfer.
Floor surface temperatures
For the sexes, due to direct contact with the human body through the soles of the feet, other values are valid. In order not to take away too much heat from a person, the temperature of the floor surface should not be lower than 15-20 ° C. And the person feels a comfortable and comfortable floor surface with a temperature of 22 0С to 24 0С. Here also the length of the person's stay in the room plays a role.
With floor heating (warm floors), the surface temperature of the floor should not be above 25-30 ° C.
Thermal inertia of the walls
The thermal inertia of the walls plays an important role both for winter and summer heat protection. Since the ability to accumulate heat is very dependent on the density, then it is better for heavy walls than for light structures. In winter, rooms with a large heat-accumulating capacity, when the heating is turned off, do not cool down so quickly, in the summer, excess energy during the day can accumulate in order to put it in the air in a cool night.
Protection against humidity
Rain (snow, ice, hail)
Appropriate protection against rain and slanting rain is necessary, such as: cornices, steeply sloping roofs, pergolas
Ground moisture
Water is not under pressure - drooping from the side, lifting the capillaries (non-pressure water is called such water that flows over the surface of the earth, seeps through the ground and collects in the pores of the earth as ground moisture)
Water under pressure (as a rule, it is groundwater, which, like a water column in the ground, presses on the structure from below and from the side.
The presence of water in building materials leads to damage and, therefore, is undesirable. Therefore, various measures are taken to isolate the structures from water. This can be achieved by the installation of waterproofing layers.
In the case of water under pressure, the following construction protective measures are used to protect against ground moisture: waterproofing concrete, waterproofing plasters, bituminous coatings, films of synthetic materials, etc.
If there is water under pressure to protect against groundwater perform the design in the form of a bath with sealing tape joints, as well as with external or internal waterproofing
Water vapor
Condensation of water vapor on the surface of enclosing structures
Condensation of water vapor inside the enclosing structures
It is obvious that moisture formed in the room should be removed from it. Otherwise, condensation may fall out on the inside of the windows and on the slopes, etc., and the result of a systematically high vapor content in the air is the appearance of mold on furniture, walls and ceilings. In addition, excess air humidity negatively affects people's health.
When providing air exchange, excess moisture is removed from the premises together with the exhaust air.
It is well known that condensate forms when the air temperature drops below the dew point. The onset of the dew point depends not only on the relative humidity of the air and the temperature inside the room, but also on the thermal insulation characteristics of the enclosing structure (ie, the temperature of the inner surface).
In order to start the formation of condensate, the air does not necessarily have to be completely cooled. It is sufficient that the temperature of the surface, which borders on the air, falls below the dew point. This process continues until the air bordering the given surface is freed from a certain amount of water and its relative humidity does not decrease.
At the same temperature, condensation loss (dew point) on the surface with a higher resistance to heat transfer will begin at a higher relative humidity. This means, for example, that the use of window structures with higher heat-shielding properties reduces the likelihood of condensation.
In order not to condense water vapor inside the enclosing structures, it is necessary to select the right layers and, most importantly, the correct sequence of layers of materials inside the structure. The external location of the insulation (with respect to the enclosing structure) is the best solution in terms of preventing the appearance of condensation, as well as in terms of heat protection (heat accumulation). The vapor barrier layer must be located only in front of the warm boundary of the layer, which is exposed to dampening.
Approximately from mid-June to mid-September, there comes a period of evaporation (drying) of moisture accumulated in the structures in the winter. The moisture must go out, so that there is no damage in the construction materials.
Noise protection
Measures for noise protection in most cases can not be carried out after the construction of the house without taking into account its structures. Often they relate to the main issues of designing and building a house.
Already before designing and erecting a house, the following provisions should be considered:
1. Orientation of the house on the site. Which rooms should be located on the street side (if the street is noisy), and which ones - from the side opposite the street
2. The planning decision of the house. Basis principle: noisy rooms next to noisy, rooms where peace is required - next to quiet rooms.
3. Choosing a constructive solution for walls, partitions and ceilings.
4. The device of windows. Provide if necessary noise-proof windows glazing.
5.Installation of doors. If an increased sound insulation is required, use doors with noise-proof seals
6. The device of water supply and water disposal. The material of the pipes, the cross-section of the pipes affect the noise of water flows. Application of elastic gaskets during passage through structures.
7. Selection and location of engineering equipment (washing machines, dryers, etc.)
8. The type of use of the premises (eg, animal rooms, music room, etc.)
Dimension Decibel (dB) is used not only to measure the intensity of sound sources, but also to measure the sound insulation of structures.
Noises:
20 db - clock ticking
30 dB - whisper, conversation of neighbors, barely understandable
50 db - talk
70 dB - loud conversation, shouting, loud radio
80 dB - street noise with strong movement
Types of sound transmission:
air noise (conversation, music, radio, television)
cabinet noise (slamming the door, flushing the water, clicking the switch, etc.)
impact noise (walking on floors / floors).
If you want to arrange a home cinema room, a music room, etc. in the house, ie. a room where the sound quality is especially important, it should be specially noted this requirement when signing a technical assignment for the design of the house. Since these facilities require special measures to ensure acoustics.
Overlapping on wooden beams because of their small surface weight have very little sound insulation from air and impact noise. But do not be afraid of this, because. for new overlaps, the problem of protection from impact noise is well resolved by constructive measures.
Soundproofing windows
depends to a large extent on:
thickness of sheet glass;
angle of incidence of sound waves (wave coincidence)
Sealing of vestibules and seams
The effect of wave coincidence can be weakened by double-glazing in that glass of different thickness is chosen. It should also be borne in mind that a thinner glass sheet should be installed on a more noisy side.
Doors . While the windows in the outer walls are the weakest point, the doors are from the point of view of sound insulation by weak places in the inner walls.
These weaknesses are:
the canvas itself (massive doors provide higher sound insulation)
sealing the door seam (using soft-spring sealing strips),
gap between the door leaf and the floor (bottom seal device)
leakage of the frame (sealing with mineral wool or foam foaming foam)
Sanitary equipment , such as bathtubs, shower trays, toilets, washbasins and kitchen sinks, must be mounted on the supports, or installed on a floating screed. When hanging barrels, bidets or sinks on a wall, they must be fixed so that they do not transmit hull noise to the walls.
Heating boilers, ventilation systems, heat pumps, as well as washing machines, drying machines, etc. Instruments should be installed on elastic supports or on a floating screed.
Fire protection
Providing the future home with maximum fire safety is possible only in case of compliance with existing regulations. Competently execute the project, which will take into account the requirements for building materials and structures, as well as for planning solutions (width of corridors, staircases, number of outputs, ruptures between buildings on the site, etc.) will only be a professional architect.
Below are some theoretical foundations for the fire-technical classification of materials and structures.
Fire classification building materials, constructions, premises, buildings, elements and parts of buildings is based on their separation according to the properties that contribute to the occurrence of dangerous fire factors and its development within the confines of the fire, limited by enclosing structures with normalized fire resistance limits, and by the external enclosing structures of the building - fire hazard, and on the properties of resistance to the effects of dangerous fire factors and their spread beyond the fire area - fire resistance.
Fire-technical classification is intended to establish the necessary requirements for fire protection of structures, premises, buildings, elements and parts of buildings, depending on their fire resistance and (or) fire hazard.
Building materials are characterized only by fire danger.
The fire hazard of building materials is determined by the following fire and technical characteristics: flammability, flammability, flame propagation over the surface, smoke-forming ability and toxicity.
Building materials are divided into non-combustible (NG) and combustible (D). Combustible building materials are divided into four groups:
Г1 (low-combustibility);
G2 (moderately flammable);
G3 (normal);
G4 (strong).
For noncombustible building materials, other indicators of fire hazard are not determined and not standardized.
Building structures are characterized by fire resistance and fire hazard.
The fire resistance index is the fire resistance limit, the fire hazard of the structure is characterized by the class of its fire hazard.
The fire resistance limit of building structures is determined by the time (in minutes) of the onset of one or several of the following limit values normalized for a given design:
loss of load capacity (R);
loss of integrity (E);
loss of heat-insulating ability (I).
Limits of fire resistance of building structures and their symbols designate in accordance with GOST 30247. At the same time, the limit of fire resistance of windows is established only by the time of the onset of loss of integrity (E).
On fire hazard, building structures are divided into four classes:
K0 (non-flammable);
K1 (low-flammable);
K2 (moderately flammable);
K3 (fire hazardous).
Now let's give some practical recommendations to ensure the fire hazard of your home.
The distance between houses must be at least 12 meters; The distance between the garage and the cottage should be 10 meters. If the garage is attached to the house, it is necessary to provide an intermediate vestibule with a metal door.
Usually in a private house for quick evacuation in case of fire, two entrances must be provided. The most important thing is that the doors always open outward.
What else can be said, all elements of the interior, for example, made of wood, should be placed no closer than 30-40 cm from stoves, fireplaces, etc. The fireplace must be installed only in a very well ventilated room surrounded by sheet iron or natural stone at a distance of at least 0.8 m.
As you know, the most combustible material for building a house is a tree. The tree species also matters: the pine and spruce are burning most quickly, but the oak is the most "resistant".
At the same time, in contrast to many fire-resistant building materials, a tree is a building material that, although it burns, but the chain of wood molecules under the influence of a fire does not change, it has good heat-shielding qualities and does not suddenly collapse without warning symptoms. The charred surface makes it difficult to spread the fire. Nevertheless, the tree significantly increases the fire load (raises the temperature of the fire).
All the wooden parts - logs, rafters, floors, walls, etc. it is necessary to impregnate with special protective substances, increasing fire resistance (flame propagation time). Most often, salt impregnations containing flame retardants are used.
Brick and concrete are fire-resistant materials, but at the same time, under the influence of the open, they lose their bearing capacity. To increase the fire safety of brick or concrete walls, a multi-layer construction is used.
The fire that "comes" from above the roof is also often found in homes with a metal / metal roof, if these materials are placed directly on the lathing or sheets of roofing material. In this case, atmospheric electricity, which needs to be discharged, accumulates in the roof during thunderstorms. To avoid this, the metal roof should be protected by laying a layer of non-combustible insulation between the sheets and the crate.
Extremely important for ensuring the fire safety of your home is also a competent solution of engineering issues, primarily electricians.
Especially carefully it is necessary to design electricity for bathrooms, saunas, swimming pools and kitchens. In particular, it is not possible to install wiring elements, sockets, switches and high-voltage lamps closer than 0,6 m from the water source.
Ceiling and wall lights should be covered with plafonds and raised at least 2 m above the water level, In the event of water entering the outlet or a hot bulb, a short circuit and, as a result, sparking and fire may occur.
In modern country houses the necessary measure of safety is the grounding of the network by means of a grounding switch. The construction of steel pins, buried in the ground at a certain depth, is connected to it by a grounding bus - it unites all parts of the engineering communications of the house that conduct current, including all metal pipes and metal parts of the building structure.
In the main electrical cabinet, a RCD (protective cut-out device) must be installed, which protects against sparking and fires in case of short circuits in the network, as well as lightning arrestors that save from pulsed overvoltage caused by a lightning strike and sudden voltage surges. Internal wiring is best done with copper - it is more durable and less brittle than aluminum.
Cables are protected by non-combustible shells of special polyethylene - this is especially important if electricity is conducted into the house by means of a suspended self-supporting cable coming from a common overhead power line.
If gas is planned in the house, special automatic sensors should be provided to cover the gas in case of a leak.
Air exchange
The requirement of energy efficiency of modern windows, characterized by a high degree of tightness, should not mean a rejection of the need for fresh air to enter the room. Proper organization of air exchange is the provision of necessary, controlled ventilation.
Providing the necessary air exchange of premises, it is possible to achieve in several ways:
1. By ventilating by opening the windows (windows);
2. Use of ventilation devices on windows;
3. Using forced ventilation of premises.
The third method is most preferable, because using it, you will always have fresh clean air in the house without drafts, sharp changes in temperature (as in the case of ventilation in winter by opening the windows). The second method can not provide the required multiplicity of air exchange in the room, depending on the conditions of use of premises. While forced ventilation can always be easily adjusted with a simple switch ("more or less"),
Seismic resistance
If you are planning to build a house in an earthquake zone, then you need to be very careful in choosing a designer. It is necessary to pay only to that design firm or to a private-working architect who has experience designing in seismic zones.
Design of buildings in seismic areas of hazardous areas should be carried out in accordance with SNIP II-7-81 *.
These norms should be observed when designing buildings and structures constructed on sites with seismicity of 7, 8 and 9 points.
When designing buildings and structures for construction in the specified seismic areas, it is necessary:
use materials, structures and structural schemes that provide the lowest values of seismic loads;
take, as a rule, symmetric constructive schemes, uniform distribution of the rigidities of structures and their masses, as well as loads on overlaps;
in buildings and structures from prefabricated elements have joints outside the zone of maximum effort, ensure the monolithic and uniformity of structures using enlarged prefabricated elements;
provide for conditions that facilitate the development of plastic deformations in structural elements and their joints, while ensuring the stability of the structure.
To ensure seismic stability of buildings and structures, seismic isolation and other systems for regulating the dynamic response of structures are allowed, provided they are designed according to special technical conditions agreed with Gosstroy of Russia.
Ecological compatibility
Under ecological housing, we mean houses that use environmentally friendly building materials, and technologies that allow a healthy indoor climate.
Dangerous to human health is dust, organic contaminants formaldehyde, biological pollutants, radon, etc.
Dust accumulates in the house and causes eye irritation, runny nose, respiratory infections and bronchitis. Methods of struggle: forced ventilation (in particular, the hood is required above the stove), constant airing and wet cleaning of the premises.
Organic pollutants. The sources are paints, solvents, aerosols, dishwashing liquids, repellents, air fresheners, etc. The main method of dealing with this evil is to observe the storage rules specified by the manufacturer. It is desirable to store household chemicals outside the home, for example, on a balcony or in a well ventilated place.
Formaldehydes. The sources are chipboards used in the production of furniture, the manufacture of decorative parts, etc., some fabrics, carpets and glues. Formaldehyde is considered to be a carcinogen. Methods of struggle: try to maintain the average temperature in the house, to air more often, especially after the appearance in the house of a new source of formaldehyde.
Biological pollutants. The sources are raw walls, ceilings and floors, carpets, furniture; improperly used air humidifiers, odor absorbers; conditioners, pets and their bedding. In damp and warm places, various microorganisms actively multiply, many of which can pose a threat to humans. The main way to combat this evil is to ventilate, dry the damp walls, carpets, etc.
Radon. Radon is dangerous for residents of the first floors. It is an inert gas, which is formed in radioactive ores and minerals and gradually comes to the surface of the earth. Sometimes radon is stored in building materials. Radon is toxic, which is due to its radioactive properties. Sanitary and epidemiological surveillance organizations can conduct radon tests. It should also air the cellars and living quarters. If radon is contained in water, then it can be disposed of with carbon filters.
When building an individual residential house, all the technical requirements to him. They are regulated by the normative documents of the Russian legislation, and it is necessary to know about them both as an architect and builder, and for the customer himself. There are many such documents, for example, SP 55.13330.2011 "SNiP 31-02-2001 Residential apartment houses", SP 20.13330.2011 "SNiP 2.01.07-85 * Loads and impacts", SP 22.13330.2011 "SNiP 2.02.01-83 * Bases of buildings and constructions », SNiP 23-01-99 *« Construction climatology », SP 52.13330.2011« SNiP 23-05-95 * Natural and artificial lighting ». Of course, it is impossible to fully convey the essence of the requirements in one article, therefore, we will focus only on the most important.
Most of what is planned in the future individual residential building, determines only the future owner. For example, the size of rooms and their location, the availability of a particular room, a list of engineering equipment and so on. It is clear to everyone that with this the house is designed for activities that take place in the home: rest, sleep, cooking and eating, hygienic procedures, so it is important to create the conditions necessary for this.
What are the main requirements for an individual apartment building?
Basic requirements for individual house, concerning the destination of premises, can be found in SNiP 31-02-2001 "Residential single-family houses". Listed the minimum list of rooms that are necessarily present in the house: kitchen, living room, bathroom or shower room, toilet, pantry, which can replace the built-in wardrobes.
There are also requirements for the minimum size of the premises. They were calculated taking into account the arrangement of the necessary furniture and equipment intended for the room. For example, according to this the minimum size of the bedroom is 8 sq. M. meters, and kitchens - 6 square meters. meters.
Strict regulations subject to the minimum height and width of rooms. According to the relevant requirements, the height of living rooms and kitchens is not less than 2.7 meters. If such rooms are located in the attic, their height should be at least 2.3 meters. In addition, these rooms must have daylight, simply put, the presence of windows is mandatory.
What are the requirements for the construction of an individual house
The basis of the house and all its structures are calculated taking into account those regulatory loads that they must withstand. Exceptions are their damage or deformation. Calculation methods strictly meet the requirements of current regulatory documents on the design, with the indication of the relevant material.
When designing, all loads must be taken into account, which can be divided into permanent and temporary, into the bearing structures of the house. It also mentions the weight of the structures themselves, pressure, loads from people, furniture and equipment that is planned in the house.
Special attention is paid to the foundation, as this is the foundation of the house. When it is designed, special importance is given to the characteristics of the ground, its aggressiveness and the presence of groundwater in it.
What are the requirements for the fire safety system of an individual house
This, perhaps, is one of the main requirements, non-observance of which can lead to sad consequences. The requirements are set out in a fairly large document, which is called the Federal Law of July 22, 2008, No. 123-FZ, "Technical Regulations on Fire Safety Requirements." Besides him, there are a number of normative documents that cover this issue. A detailed analysis of the documents shows their similarity, so we will dwell only on the main points.
The design and further construction of an individual cottage must necessarily include measures to prevent the occurrence of a fire. In addition, it should be possible to evacuate people in case of fire on the adjacent territory. In case of fire, a number of measures are provided to prevent the penetration of fire into neighboring buildings, providing free access to the house for extinguishing the fire and saving people.
In addition to all of the above, the possibility of a sudden occurrence of fire inside the room and its further exit to the surface must be taken into account.
The requirements for engineering communications at home
It's not a secret that any residential building has a number of utilities: heating, water supply, ventilation, sewerage and electricity. But not everyone knows that certain requirements are also imposed on them.
The heating system is designed to maintain the temperature necessary for the life of the house throughout the heating season. The temperature in the living quarters should not be lower than 20 ° C, in the kitchen and toilet - not lower than 18 ° C, in the bathroom or shower room - not less than 24 ° C.
The ventilation system ensures a uniform supply of air and its further distribution. It cleans it and maintains the necessary quality. In those rooms where it is possible to release harmful substances or unpleasant odors, it is planned to remove air immediately, bypassing any ventilation ducts, outwards.
The gas pipeline is conducted to the house or to the kitchen, or to a specially allocated room, a boiler room. If there is no main gas, the house is allowed to use gas cylinders not more than 50 liters.
All requirements must be met, otherwise the house will not receive the status of an individual dwelling house and will not be suitable for housing.
So briefly you can express the aspirations of the future owner of the house. Denouncing these thoughts in a more rigorous, normative language, we will define a number of requirements for modern houses, the fulfillment of which will guarantee the desired comfort of the dwelling, its sanitary and hygienic qualities, safety - environmental, fire and other - energy efficiency, etc. In fact, the described requirements are applicable not only to low-rise buildings, but also to any residential building.
Functional feasibility
The functional feasibility of the design solution of the house is to match its premises to its purpose. Indeed, a house intended for living a lonely person with a small set of interests should significantly differ from the house in which a large family with households of different generations will live, who, in addition, like to receive guests.
The number of people living in the house, their way of life, occupation, interests - everything affects the project of the house and leads to the corresponding ones:
- architecture of the house;
- planning solutions of premises;
- constructive decisions;
- engineering equipment;
- interior and exterior decoration of the house, etc.
Engineering Requirements
Engineering requirements are that building objects must be reliable.
Reliability is a very capacious engineering concept, which includes several specific design characteristics, we describe them.
Strength
Strength - the ability of the building to perceive loads and force effects (mechanical) without destruction during a specified period of operation.
A distinctive feature of the concept of strength is that it is a calculated value. Constructions and their elements are calculated by compressive strength, stretching, crushing, chipping, etc.
Strength of the building is provided, first of all, by the strength of its supporting structures. But no construction of the building or any other structure does not work by itself - all the structures are connected to each other in a single spatial system. The fact that the building is a unified system proves a possible paradox: all the constructions are durable, and the building has collapsed. Therefore, in order to fulfill the requirement of the strength of the building as a whole, the strength of its individual structures is not enough - it must be stable and rigid.
The task of buildings is to stand firm.
There are areas of construction for which the implementation of the requirements of sustainability is vital, for example, earthquake-prone areas.
Let's give an example of stability. The long wall, 120 mm long and 1.5 m high, laid out of bricks under the force of the wind, which develops in inclement weather in the central strip of Russia, is overturned. At a thickness of 250 mm, the wall can stand at a height of up to 3 m. A wall of 380 mm in thickness and up to 5 m high will also withstand wind load. If we talk about the wall of the house, then the stability of the outer wall helps to provide transverse walls, which serve as supports for the outer wall with the wind pressure. Therefore, the height of the house can be much larger.
Stiffness is the ability of a building or its individual structures to preserve the unchangeability of a form, i.e. resist deformations. Of course, it is impossible to completely avoid deformations, but the values of deformations should be within the limits permitted by the appropriate standards.
You can provide rigidity to the system in two ways.
The first method makes the junction node rigid, in which the possibility of moving one element relative to the other is excluded; such a node is capable of perceiving nodal moments. This will happen if you enter an element forming a triangle into the zone of the node - a geometrically immutable shape. So the rack and beam system becomes a frame. The same effect we will observe if the slabs or joists of the ceiling are "hard" embedded in the walls. For example, in monolithic buildings The joints of walls and ceilings are rigid.
Another way to ensure the rigidity of the system is used if it is not possible to make the node rigid or not enough. Then the system is given a stiffness, introducing a diagonal element - a brace. Such an element is called a link, and the system is called a link. In the practice of low-rise construction, this can be seen in the example of the now popular frame houses (half-timbered houses). The same braces are introduced to ensure rigidity pitched roofs, only here the braces are sealed between the posts.
Stiffness and stability are interrelated. Loss of rigidity, i. the excess of the permissible deformation values invariably leads to a loss of stability and, consequently, to destruction.
The relationship of rigidity and stability is particularly indicative on stand-alone columns. First, inadequate rigidity of the column will lead to the formation of cracks in the stretched zone of the structure, then the crushing of concrete begins in the compressed zone, and the result is the loss of stability and destruction of the column.
A similar situation can be observed in the walls.
Prevent this outcome by increasing the thickness of the wall, or by designing pilasters or buttresses and other techniques.
Some designs, for example overlap, rely on deformation-deflections. If the permissible norms of deflections are exceeded, the overlap is strengthened.
Durability
To be clear, consider this example. The residential building stands firmly, is not destroyed and is capable of perceiving design loads. However, the building can not be used as a dwelling, since its thermal protection is not ensured (the thickness of the walls is insufficient for thermal protection, the heater is destroyed or there is no insulation, the wind blows into the formed cracks), due to lack of proper ventilation, moisture (condensation) and fungus form on the walls, The roof flows, the floor freezes, and so on. Therefore, in a given mode of operation - as a dwelling with all its sanitary and hygienic requirements - the house can not be used.
The durability and strength of the building are interlocking properties: unsecured longevity will lead to an accelerated loss of the strength of the building and, ultimately, to its destruction.
The stability of the operational qualities of the building as a whole and its individual structures is primarily ensured by building materials that must have certain properties.
Frost resistance is the ability of a water-saturated material to retain its strength under multiple freeze / thaw cycles. If the material does not have this property, the moisture expanding during freezing in pores shakes the intermolecular bonds, destroys them, cracks appear, they increase in size, and the material breaks down.
Moisture resistance - the ability of a material to resist moisture, causing swelling, softening, warping, stratification and, as a result, destruction of the material. To prevent such troubles with insufficiently moisture-resistant material used in a humid environment, measures should be taken to protect it.
A few examples. Take a tree - a hygroscopic natural material. The house, whose facade planes are finished with natural wood, undoubtedly looks beautiful, but requires constant maintenance - coatings with special compounds, varnishes, paints, etc. Some types of insulation are required for protection. After a moisture-saturated insulation can not perform the prescribed functions - to keep the heat in the house. To protect the insulation apply special foils.
Corrosion resistance. Corrosion, as it were, "eats" the material, shortening its service life - durability. Of course, we do not consider here buildings with chemical and other industries. For a residential building an aggressive environment, the impact of which is perceived by the external surfaces of the house - from the foundation to the roof, - is the atmospheric moisture and groundwater.
Particularly corrosive open steel structures. For example, a steel roof without adequate protection rusts. A house with a rusty roof will not collapse, but the roof will flow, which will lead to the unfitness of the home.
The serious matter is if the bearing structures are corroded. From rolling steel, for example, supports can be made under the balcony, loggia. Corrosion will reduce the design cross-section of the support, thereby reducing its bearing capacity. In order not to lose the strength of the support in this way, it is protected by special compositions, paints, etc. or they become obrounded.
Biostability is the ability of a material to withstand the destructive effects of microorganisms, in particular mold and fungi. Mold is a syndrome of a "sick home". Mushrooms and mold develop where the nutrient medium is created for them: constant dampness in the room, insufficient ventilation, etc. The fungus is harmful to humans, causing various diseases, including asthma and oncology. The development of such organisms in the house leads to the unfitness of housing, i.e. its specified qualities characterizing durability are not fulfilled.
Fungi and mold can develop not only on the inner surfaces of the house, but also on the outside: for example, on natural tiles for a few years a dense layer of mushrooms is formed, from which the roof needs to be cleaned periodically.
We listed the main properties that affect the longevity of materials. Their significance for different areas of construction and operating conditions is different; accounting for this is done on the basis of appropriate design standards.
Durability of structures and buildings as a whole depends on the service life of individual structural elements, including embedded elements and fasteners, connections, interfaces, etc. Indeed, substandard fasteners, for example brackets, which connect the slabs between themselves, destroy the integrity of the structure of the floor, and it will collapse.
The process of small continuous deformations of the material under long-term loading (creep of concrete, relaxation of steel) also affects the durability of the building.
Fire safety of a building
Fire safety of a building is the most stringent requirement, because it is connected with the life of people. Therefore, the issues of design solutions for houses, choice of construction and finishing materials are especially carefully thought out. Let's talk about this in sufficient detail. There are concepts of fire danger and fire safety of the building.
Please pay attention. Fire safety deals with the prevention of fire, and fire danger - the possibility of a fire.
The fire hazard of the building is considered in relation to construction and finishing materials. Properties of materials and their ability to form dangerous hazards of fire divide the materials into the following groups:
- non-combustible - marked as NG;
- combustible: low-flammable - G1, moderately flammable - G2, normally flammable - GZ and strong flammable - G4.
Non-combustible materials include natural stone, reinforced concrete, steel, aerated concrete, basalt mineral wool (insulation) and others.
The combustible materials are wood, expanded polystyrene (insulation), all sorts of finishing materials that have not been treated to improve fire resistance.
The degree of flammability of the materials affects the design decisions. For example, for the allocation of fire compartments in multi-section buildings, fireproof walls of non-combustible materials (firewalls) are built, which prevent the spread of fire along the adjacent compartments. If the coating materials are made of a group of NG, the firewall can not rise above the roof. Of course, in a house of cottage type firewalls do not suit, but in blocked houses they are mandatory.
On the totality of these characteristics, the building structures are assigned fire hazard classes:
- non-flammable - К0;
- low-flammable - K1;
- moderately dangerous - K2;
- fire hazardous - short circuit.
Numerical values of the assignment of structures to a particular class are determined by appropriate methods.
The most fire-resistant are designed vertical supporting structures - columns and walls: they must last longer than all others. Indeed, when the collapse of these structures can not stand the whole building. They are calculated only on the bearing capacity (indicator R). For all indicators, an overlap is calculated, and in a building of the same degree of fire resistance, the overlap should last only 1 hour in a fire condition.
Sanitary and hygienic requirements
Sanitary and hygienic requirements. Probably, if you do not think about the above specific requirements, for a person, the sanitary and hygienic living conditions are the most important: they are related to health. Sanitary and hygienic qualities of the dwelling, which are standardized by the relevant standards, include:
- the time (duration) of insolation;
- natural illumination;
- the state of the air in the room;
- noise impact.
The totality of these parameters determines the microclimate of the room.
Insolation
Insolation has a light, ultraviolet and thermal effect. This is necessary for man, since light and ultraviolet irradiation has a strengthening effect on him and his psychophysiological state.
Natural illumination
Natural illumination should be provided in all living rooms. In kitchens, artificial lighting is allowed.
To infiltration, we also include the penetration of air through looseness of the structure, for example, window frames.
Noise protection
Noise protection. The trouble is that people do not adapt to noise. He can only feel that he is used to the rumbling outside the window and does not notice him. In fact, noise is perceived by the brain and acts extremely insidiously on a person.
Of course, if the house is in a village or on the seashore, and only the singing of birds or the sound of the surf can disturb sleep, this question is not relevant. Harmful impact has only anthropogenic, not natural, noise. It is necessary to solve noise protection issues if transport noise is disturbing, which is often observed in cases of location of townhouses along major roads.
Modern design standards limit the amount of penetrating noise differentially for day and night time. The noise level is measured in decibels.
Protection from noise is achieved by a complex of town-planning, volume-planning and constructive measures. Here are some of them.
Town-planning measures include the installation of soundproof walls along the tracks, the device of the screen from low-rise non-residential buildings (for example, warehouses, garages, objects of trade, entertainment, etc.), screening by multi-storey noise-proof houses (in such houses special volume-planning decisions of buildings and apartments ).
Constructive obstruction is primarily the massiveness of the external walls (200 ... 300 kg / m2). Trying to protect yourself from noise, do not rely on glass bags, so as not to be clogged without access to air. Double-glazed windows give a noise-protective effect only in the closed state. To ensure the natural ventilation of rooms facing a noisy highway, the windows are equipped with special muffler valves or, refusing natural ventilation, resort to air conditioning with fresh air.
Thermal protection
Thermal protection of the building is necessary to ensure a comfortable temperature and humidity regime in the premises.
In the matter of creating comfortable housing, the orientation toward keeping the heat in the house took decisive importance. In a specific climatic zone, a heat engineering calculation is carried out for each enclosing structure intended to "store" heat (external walls, coatings, ceilings above a cold cellar, etc.). For the sake of completeness, we present some of the basics of heat engineering.
The main thermo-technical index of the material is its thermal resistance R. It characterizes the resistance of the material to the passage of heat through it. The higher this value, the better the heat-protective properties of the material.
As a rule, the enclosing structure consists of several layers: in addition to the carrier layer, its composition includes finishing layers, soundproofing, insulating, etc.
Calculations for the thermal protection of the building proceed on the basis of two conditions:
- from sanitary and hygienic and comfortable conditions; the decisive factor here is the average temperature of the construction and climatic area of the erection of the building and the duration of the heating season;
- from the conditions of energy saving.
It is interesting. Notice how cold our country is: there is not a single district where there would be a positive temperature of the coldest five-day period.
Suppose we designed outer wall with good heat-protective properties, but the cold is still coming. Why? Here there is such a thing as a bridge of cold - a zone through which heat leaves the building (and not cold penetrates the building). The cold bridge is formed when a material or element with a higher thermal conductivity is included in a good thermal engineering characteristic of the enclosing structure. For example, if a reinforced concrete slab passes through brick wall, this creates conditions for intensive heat loss in this zone. How to eliminate cold bridges, will be told in the relevant chapters.
To ensure the comfort of a home, the concept of thermal stability of a structure (thermal inertia) is always taken into account. Heat resistance characterizes the ability of the material of the enclosing structure to withstand the temperature fluctuations of the outside air. The more heat resistance, the more difficult it is to change the temperature inside the building.
In the case of heat protection at home, another important factor is the vapor tightness of the materials of the enclosing structure.
Steam-penetration is the penetration of water vapor into the outer wall from the side of the room (diffusion of water vapor). Steam-penetration is the most complex phenomenon. It is not always taken into account in the design, but it is fraught with the loss of the construction of one of its main purposes - to create a comfortable warm housing.
The location of the dew point in the thickness of the enclosing heat-shielding structure is dangerous in terms of reducing the frost and moisture resistance of materials and, as a consequence, leads to a deterioration in their heat-shielding properties (for wood this also means a loss of biostability). To prevent this, vapor barrier materials are used.
However, if the dew point reaches the exposed outer surface of the wall or is formed in a ventilated cavity, then no damage will result. Condensate is dangerous in a confined space, where the condensate formed from nowhere has nowhere to go. It cyclically freezes / thaws in the pores of the material, thus causing a destructive force. This is dangerous ceramic hollow stones, which eventually begin to spoil the facades of buildings (such a picture can be seen on the building of the Foreign Ministry, on the houses on Prospect Mira in Moscow).
The architectural expressiveness of the house is connected with the concept of beauty in architecture.
Of course, the dwelling should be not only functional, but also to evoke pleasant emotions by its appearance, to fit into the environment. This is especially true for low-rise private housing. At first glance, it may seem that these are only architectural issues. But without architecture, architecture can not be created. Therefore, the task before the architect is to design a house that the structures would not be disfigured, but, on the contrary, complemented, beat, sometimes even served as the basis for the architectural solution. For example, boring supports (columns, columns) can be played with color, finishing materials, give them an interesting, attention-getting form; they can also be made the basis of zoning or even the center of the composition, "turning", for example, into a fireplace, etc. The architect's possibilities are unlimited here.
The economic side of the issue is one of the most important requirements for building projects. Value for money is considered at all stages: from the cost of building materials and construction of the building to maintenance costs for its maintenance. The final decision is made when all the requirements of the customer are taken into account, which can lead to a more expensive option, but to meet its interests. For example, an environmentally friendly house is sometimes more expensive, but it is justified costs.