Before starting a major overhaul, which involves making changes to the layout of the apartment, it is necessary to identify bearing walls. By law, such building structures are prohibited from dismantling, as it reduces the reliability and durability of the building. A preliminary determination of the load-bearing structures of the apartment will save the owner from many problems with government agencies that control compliance with current building codes and regulations.
in Khrushchev and panel houses There are load-bearing walls and thin interior partitions. Only non-bearing structures can be dismantled to unite the premises, the work with which will not lead to the emergence of dangerous buildings for users emergencies. The need to dismantle and move partitions arises quite often, the reason for this is the inconvenient arrangement of rooms in old apartment buildings and their small size. Simply put, the rooms are too small for people to live comfortably, and their demolition frees up additional usable space.
But not a single load-bearing wall should be destroyed during the repair. Such partitions perform very important features in the house - they take on the weight of the higher building structures building. If the load-bearing wall cannot withstand all the load it receives, it will begin to collapse, which can eventually lead to the collapse of entire sections of the house and human casualties.
So that the repair does not lead to such negative consequences and you need to know in advance which walls can be dismantled and which cannot. There are two main ways to identify important structural elements of a building:
In a panel house, as in any other, it is easiest to determine the purpose of internal structural elements using the technical passport of the apartment. If for some reason you do not have technical documentation, a load-bearing wall can be identified by a number of important features. The first thing you need to pay attention to when examining a septum is its thickness. In panel houses, load-bearing walls are always much thicker than usual. interior partitions.
By building regulations minimum thickness load-bearing partition in a panel house must be at least 12 cm. This is a net size, excluding facing materials on the wall, of which there can be quite a lot (plaster, wallpaper, paint, etc.). Interior partitions that do not fulfill load-bearing functions, have a thickness in the range of 8-10 cm (excluding finishing).
That is, to determine the load-bearing walls, everything must be measured, having previously cleared them of facing materials. Only once this has been determined, it is possible to proceed with the planning of a major renovation, choosing the appropriate methods, means and solutions for the reconstruction of a residential facility.
When taking measurements, it should be borne in mind that all the walls in the old nine-story panel houses consist of panels, and therefore many of them have load-bearing functions, which makes it impossible to dismantle them. It is forbidden to carry out a lot of work with load-bearing walls, in addition to dismantling - to create door and window openings in them without obtaining the appropriate permits from the responsible authorities, and even ditch them to install communications.
In Khrushchev, it is quite simple to determine the purpose of the walls. To do this, you can use the technical passport of a residential facility, and if it is not there, take special measurements. All Khrushchev houses are characterized by the same layout, and the supporting structures in them are usually only those that separate the apartment from other apartments, landing and streets, and all internal partitions simply separate the rooms and can be safely dismantled.
However, it is not necessary to immediately start dismantling work, it is recommended to first take measurements and find out the thickness of all internal walls. In Khrushchev, the load-bearing wall always has a thickness of more than 12 cm without finishing layers. If the wall cleared of cladding is thicker than 12 cm, it can be demolished without fear of negative consequences.
The wall separating the apartment and the balcony usually does not perform any load-bearing functions in Khrushchev. But dismantling it is still prohibited. The balcony is a cold zone and the wall separating it from the apartment is needed to save heat. If it is demolished, the apartment will be poorly protected from external weather conditions, which is why it is currently impossible to obtain permission to combine a room with a balcony from the housing inspection, with which redevelopment is being coordinated.
You can also find out about the possibility of transferring and disassembling a wall using drilling. In Khrushchev, the load-bearing walls are very durable and sometimes you have to change the drills one by one to create holes in them. To create a hole in a curtain wall, almost no effort is needed, the drill passes through it very easily.
It is believed that the load-bearing wall in any apartment can be easily found using technical documentation, for example, a floor plan. apartment building. This is true, but to define functions internal partitions must be able to work with project documentation, to understand legend, read diagrams, etc.
Unfortunately, there is no single generally accepted designation of load-bearing walls on plans that would be used by all design companies, developers and other organizations, so the owner often has to sit over the received drawings for a long time before he can find out which wall is load-bearing and which is not.
On the architectural and construction plans of the working project for the construction of an apartment building, load-bearing walls are usually distinguished by special shading. On plans from the BTI, such structures are indicated with a greater thickness than simple interior partitions, but not always. It is not uncommon for a wall to be marked with a thin line on the plans of old houses, but in reality it is a load-bearing one.
Owners are strongly discouraged from trying to perform wall measurements or data from the data sheet based on the results obtained. It is better to play it safe, order documentation for the house from the BTI and entrust the task of assessing the possibilities of redevelopment to professional designers.
Redevelopment is considered by modern legislation as a major, complex and responsible repair, which, if performed incorrectly, can cause a lot of harm. apartment building and its inhabitants. That is why the Housing Code describes in detail the correct procedure for redevelopment, from which it is impossible to deviate in any case.
The procedure provided for by law involves the preliminary design of a major overhaul and the coordination of the developed project documentation with the housing inspection or local administration locality. In order for the project to be successfully approved, it should be ordered from professional designers, whose qualifications are confirmed by SRO approvals and licenses from state regulatory authorities.
For approval at the MFC, it is necessary to submit a package of documents, which includes:
These documents will be transferred from the MFC to the responsible authority for approval, after which they will be reviewed within 45 days and the owner will receive a notification whether he is allowed to carry out redevelopment. If the housing inspectorate considers that the planned repairs may adversely affect the building, the owner will be prohibited from implementing the project documentation.
It is not worth ignoring the requirements of the legislation on the need to coordinate a major overhaul. If you perform redevelopment without the appropriate permits, you can not only violate the integrity of the house and endanger your own and other people's health, but also receive an order from the housing inspectorate requiring you to pay a fine established by law (up to 2500 rubles for individuals) and return the home to its original layout, which will have to spend an impressive amount of money.
Many people, especially those living in Khrushchev apartments, are trying to remake their small and uncomfortable apartments using redevelopment. But it is one thing to complete it in an individual building, and quite another to change the doorway or move the partition in a high-rise building, where almost every wall is load-bearing. All this ensures the safety of residents in combination with all technical design Houses.
What is rescheduling? According to the housing code, this concept includes all changes in the configuration of the apartment that require them to be included in the technical passport. This:
All these types of changes in the apartment are related to redevelopment and in the relevant authorities.
Most often, redevelopment is associated with the demolition of interior partitions. But which walls can be touched, and which not - not everyone knows. The reckless demolition of structures leads to a change in the action of forces on the remaining surfaces and rooms located below. In addition, ceilings left without support may not withstand the load and collapse at any time. Since, in addition to separating different rooms, wall elements serve as supports ceiling for all above located, similar structural elements.
The main (bearing) walls in practice are perpendicular to the floor beams. If it is made from concrete slabs, then their ends rest on the surface of the supporting structure. Usually these are walls between apartments and blocks, or external. As a rule, only partitions are equipped inside the apartment.
Is it possible to determine the purpose of the wall yourself? Certainly. According to its thickness or the material from which it was built. In panel houses indoor units are up to 120 mm thick. Therefore, they can be considered partitions (their thickness ranges from 80-120 mm). The bearing surface must be at least 140 mm thick. Most often, in such houses, the outer walls are made with a thickness of 200 mm or more. In brick houses - external, load-bearing structures have a thickness of 380 mm or more, inter-apartment - 250 mm, and partitions 120 or 80 mm.
As a material for load-bearing walls in prefabricated houses, wall or inter-apartment blocks made of reinforced concrete with various additives are most often used to facilitate construction and increase thermal protection. Internal partitions in 90% panel houses made of gypsum concrete panels. In brick buildings, the main material for all walls is red and silicate brick, differing in size. Gypsum concrete panels can also be used as partitions in them.
Of course, no one is going to demolish the outer walls, but the partitions can be removed after obtaining the appropriate permission. To accurately determine which of the walls is the carrier, it is best to use the BTI data - a detailed floor plan. There, thicker lines mark all the main walls, and partitions that do not have such functions are marked with thinner lines.
In any case, before proceeding with the demolition of a particular wall and its transfer, you need to consult a qualified specialist. As well as a complete calculation, taking into account the distribution of loads that must be transferred from old structures to newly built ones. In addition, you may have to change the power supply scheme. In addition, it must be borne in mind that the uncoordinated demolition of the walls of the premises may put it on sale or execution of donation documents, etc. But that's not all. Such actions are considered illegal and entail penalties, subpoenas, and may even lead to the confiscation of the apartment.
Therefore, the coordination of the redevelopment project is necessary in any case. What is needed for that?
Those who decide to do construction or redevelopment in an already erected building should know what a load-bearing wall is and what threatens its destruction. The purpose of the load-bearing wall is the ability to take on loads from other parts of the building, ceilings and roofs. In order not to face the danger of destruction of the building, before starting work, you need to determine which walls are load-bearing and carry out all the planned activities without touching these structures.
Walls are the main structural part of a building, but not all of them are able to withstand the load coming from floors and roofs. For this purpose, each building is equipped with load-bearing walls. To divide the space in the built house, partitions help, which can only withstand the load from their own weight. Such walls are called self-supporting. The purpose of each non-bearing wall is to act as a space delimiter, if necessary, simply allocate a separate room.
Simply put, load-bearing walls are structures on which something rests. In each building, load-bearing and non-bearing walls play an important role, but if the load-bearing is a reliable support, a high-quality frame of the building, then it is not a load-bearing partition that, if desired, can be demolished during redevelopment without causing damage to the building. All walls are divided into load-bearing, self-supporting and non-bearing. Already by the name it becomes clear which of them are being built in order to take on the main load.
Such a partition can be built from:
As self-supporting walls in panel houses I install monolithic slabs. Such non-load-bearing walls can be used to create an additional passage by cutting openings into them and installing doors.
To correctly recognize which walls are load-bearing means to successfully carry out redevelopment without violating building codes and rules, without risking creating a situation, the end result of which will be the destruction of the building. , means to change the distribution of the load, and this will lead to a skew of the building, collapse of the ceiling and cracking of the remaining capital structures.
They provide security not only for the apartment in which repairs are underway or redevelopment is planned. The safety of dwellings located on the lower floors depends on their quality and integrity. The main difference between load-bearing structures and self-supporting structures is. Knowing the differences is not enough, you need to be able to correctly determine which wall is load-bearing.
It is necessary to know exactly which walls can be demolished during redevelopment, and which should remain intact, at what thickness it is permissible to make an opening in the wall, and when it is too dangerous to perform such work.
There are certain requirements that I impose on load-bearing walls:
Another feature of the load-bearing wall, thanks to which such structures differ, is the uniform distribution of the horizontal load exerted by the floor slabs. An important criterion strength, reliability and stability is the thickness of the bearing wall. This value is set for brick, solid and panel interior walls.
Strict compliance established norms facilitates the determination of a load-bearing wall in any building or room.
Having learned what a load-bearing wall is, you can understand how important the construction of this structure is in strict accordance with all existing regulations and rules. Such walls are a natural continuation of the building itself, the beginning of which is the foundation. To avoid great difficulties and troubles in the process of redevelopment, you need to know how to determine the load-bearing wall in the apartment. In most cases, it is enough to carefully study technical documentation and determine the location of the load-bearing walls on the building plan. However, it happens that there is no plan and you have to independently establish the quality and purpose of the erected structures.
The peculiarity of the construction of panel buildings is that in a monolithic house as supporting structure reinforced concrete panels are used. Their thickness is from 100 to 200 mm. The role of interior partitions are structures made of gypsum concrete panels, and their thickness does not exceed 80-100 mm. Thus, by measuring the thickness of the wall, it is possible to recognize the load-bearing wall, which is strictly forbidden to be demolished in such a building. non-compliance established rules lead to inevitable deflection and collapse of the floor.
One of key indicators is the thickness of the bearing walls in brick houses. To distinguish a load-bearing wall, you need to know its thickness, but it is better to have a building plan on which all load-bearing structures are marked. Self-supporting walls in an apartment, as a rule, are much thinner than capital structures. The thickness of the walls that take the load from their own weight varies from 5 cm to 400 mm. Such a partition can be built of drywall, but more often it is a wall built of brick (half-brick masonry).
An experienced craftsman will tell you how to find out if it is a load-bearing wall or not. brick house, but the size of the structure will also help to understand this. Its peculiarity lies in the fact that the thickness of the brick wall is a multiple of this brick parameter, plus the thickness of the adhesive layer and finishing material. Thus, it is possible to find out which wall is in front of the builders. The thickness of the partition does not exceed 380 mm, and for a load-bearing wall, this size is minimal. The greatest thickness of the bearing wall in a brick house reaches 640 mm. The peculiarity of this structure is that it is possible to make an opening in such walls. This is justified by the ability to provide additional reinforcement to maintain a uniform distribution of the horizontal load.
To distinguish which walls can be demolished and which are strictly prohibited, their parameters will help:
Brick houses or were built according to a constructive plan, hallmark which is the presence of 3 longitudinal load-bearing walls (on the plan green color) and transverse walls, called stiffening diaphragms (highlighted in blue).
The owners of apartments whose windows overlooked the front side of the house had the opportunity to build an extension or even make additional window. You can get more detailed answers to all existing questions by watching the video.
When starting to carry out work on the redevelopment of housing, you need to carefully study the plan of the apartment, which indicates the dimensions and purpose of the walls, if there is no opportunity to familiarize yourself with the documentation, then you should not make responsible decisions without measuring the thickness of the walls.
Getting Started overhaul or redevelopment of the house, you must first understand what it is, load-bearing walls, and correctly determine where they are placed in the house. After all, even an incorrectly executed small opening in the load-bearing wall threatens to turn into a partial or even complete destruction of the entire structure of the house.
The main difference, by which you can accurately determine which partition is in front of you, is the load it takes on. Ordinary interior partitions do not hold anything on themselves and are only loaded by their own weight, which is why they are called that - self-supporting walls. Partitions that take on not only their own weight, but also part of the weight of structures located above them: interfloor floor slabs, ceiling beams or walls of the upper floors are load-bearing.
Therefore, it is strongly not recommended to cut openings in load-bearing walls, and it is strictly forbidden to demolish them completely - this can cause the destruction of the house. Self-supporting walls perform an exclusively separating and decorative function, therefore, if necessary, they can be rebuilt without problems and even completely removed - the strength and stability of the house will not suffer from this at all.
But, having an idea of what is the difference between the walls, you also need to know how to determine the load-bearing wall. The easiest way to see this is on the plan of the house - it is enough to have at least minimal skills in reading such documents. But often there are cases when the plan cannot be found. In this case, such a wall can be determined by the following features:
Regardless of the material of construction, almost all external walls are load-bearing. They will also be partitions facing flight of stairs. In the vast majority of cases, partitions separating neighboring apartments also fall under this definition.
In many cases, the purpose of a wall can be determined by its thickness, although there are many nuances here. In brick houses, all walls with a thickness of 380 mm or more are load-bearing. The calculation is simple: the width of one standard brick is 120 mm, the laying seam is 10 mm. Accordingly, 3x120 mm \u003d 360 mm + 2 seams of 10 mm each - another 20 mm, and in the end - 380 mm.
Standard interior partitions in a brick house are made in 1-1.5 bricks, i.e. their thickness does not exceed 180 mm. The most difficult option is if their thickness is 250 mm (this often happens in houses built according to individual projects after 1990). In this case, one cannot do without the involvement of a specialist, since only he can figure out what functions such a partition performs. Important nuance- the thickness of the walls should be taken without a finishing layer.
In panel and block houses, all walls with a thickness of 140 mm or more are load-bearing. The thickness of interior partitions is only 80-100 mm, but they are panel apartments very little. In fact, in such houses, almost all the walls are load-bearing, so it is very difficult to redevelop such apartments, especially at your own discretion. It happens, although rarely, that the thickness of interior partitions in a panel house is 120 mm. In this case, there is no other way out than to find out from specialists which partitions can be rebuilt and which cannot.
Much better is the case with apartments in the "Khrushchev". Used in construction standard scheme: the bearing walls in the "Khrushchev" are all longitudinal, and the partitions are all transverse. In such houses, the wall separating the balcony from the living room is not under heavy load and can be dismantled.
In load-bearing internal partitions, the arrangement of any opening is undesirable, but nevertheless they often have to be done, for example, to install interior door. However, the number, size and location of these openings are calculated by experts at the design stage of the house.
If during redevelopment it became necessary to make an opening in the load-bearing wall, then in no case should you do it yourself. Firstly, it is very dangerous, and secondly, in the future, an apartment with a “left”, illegal redevelopment will be impossible to sell, donate, or issue an inheritance on it, and it will be almost impossible to legalize and receive a project.
Therefore, if you decide to redevelop the apartment, then first issue all the necessary permits and approvals in the relevant public services.
If during the work there is a need for some kind of manipulation with the load-bearing wall, then it is imperative to involve specialists for their implementation. And to fulfill partial dismantling(in the event that you need to make a new door or window opening in a load-bearing wall), you need to invite an engineer from a company specializing in such work (and having the appropriate permits and licenses) by concluding a written contract with it.
Such specialists know exactly how to properly dismantle part of the partition, how to increase its strength in order to prevent destruction, in which cases it is necessary to install an additional support, and in which it is possible to do with a horizontal metal or reinforced concrete lintel. Therefore, the chances that everything will be in order as a result are very high. And it is also important that in case of poor-quality performance of work, you still have the opportunity to demand compensation for damage through the court.
When deciding whether to redevelop the house on your own or not, remember that the slightest mistake in the calculations and performance of such work puts at risk not only your life, but also the lives of your loved ones, and if it comes to high-rise buildings, then the lives of many of your neighbors, because even an inconspicuous microcrack in a load-bearing wall can cause the collapse of the entire house, and restoring the solidity of such a wall often costs much more than all the redevelopment of the house.
Today, very often, when creating interior design, they resort to redevelopment of the premises. For redevelopment, it is necessary to determine the bearing walls and additional partitions located in the apartment. In some rooms, the definition of such walls does not involve much effort, in others it can be difficult. Today, in almost all apartments, load-bearing walls are used in construction, although in some buildings they can be replaced by beams and columns. One of the most affordable and easy ways to determine the bearing walls is the initial inspection of the apartment plan, which can be found in the data sheet. On the plan, such walls are clearly marked, often they have a certain shading, and their thickness is much greater than the thickness of other partitions. Bearing walls have certain characteristics.
To determine the load-bearing walls, it is imperative to use the plan. When redevelopment, it is necessary to contact the specialists for permission to dismantle the partitions.
Even if you plan to move the doorway, you need to have certain documents that must be provided by employees of the BTI or other relevant government agencies. In the event that an illegal redevelopment has been made in the apartment, it becomes impossible to sell it, and obtaining permission for redevelopment after its implementation is quite problematic.
Any work with the walls should be treated with full responsibility, because even the slightest crack in the load-bearing wall can be fraught with the entire structure of the building. Carrying out work with load-bearing walls It is possible to carry out some work with load-bearing walls, however, any actions must be carried out exclusively by competent specialists.
Important
A constructive plan will help to detect not only the load-bearing walls in the house, but also the columns and beams of the post-and-beam system, as well as the floor slabs that rest on them. If for some reason you were unable to obtain a constructive plan of the building, then we will determine the walls according to their characteristic features.
Again, you can use detailed plan apartment, which is drawn in the data sheet or in the house book. But in this case, you will be able to determine the bearing walls only on the condition that you are not new to construction and planning.
How to identify a load bearing wall? Which walls are load-bearing can be recognized by: 1. By location. External self-supporting walls. Walls facing stairwell. Internal walls facing neighboring apartments.
2. According to the thickness and materials used.
The wall can be indicated by a thin line and at the same time be a carrier. Determination of load-bearing walls by thickness The second way to find out which wall is load-bearing is by its location and thickness.
Bearing walls in a brick house The thickness of the walls in brick houses is a multiple of the brick size (120 mm), plus the thickness of the mortar joint (10 mm), if there is more than one masonry. Respectively, brick walls can be 120, 250, 380, 520, 640 mm thick, etc.
Mainly in brick residential buildings internal partitions are made of brick or gypsum concrete panels 80 or 120 mm thick. Inter-apartment partitions 250 mm thick brick or 200 mm double panels with air gap.
Attention
Bearing walls in a brick house have a thickness of 380 mm. Majority brick houses built according to standard series- these are the so-called "Stalinka" and "Khrushchev".
Representatives of authorized organizations, engineers licensed for this construction activity should monitor the process and carry out calculations of such columns. Note! It is impossible to sell an apartment with an illegal redevelopment, and it will be very difficult and problematic to get a project for an already converted apartment.
It is not necessary to think that the planned work is insignificant, and it is not worth it to call the brigade. The slightest mistake can cost the lives of many people, because an imperceptible microcrack in the load-bearing wall can eventually lead to the collapse of the building.
Work carried out on load-bearing walls Mounting a support during the demolition of a load-bearing wall Having decided to work on load-bearing walls, for example, ditching ditches, do it with the utmost care.
The thickness of the load-bearing wall can be: Brick load-bearing walls, the thickness of which is more than 38 centimeters. Reinforced concrete panels in panel houses, the thickness of which is not less than 14-20 centimeters. If the house is monolithic, then any wall with a thickness of 20-30 centimeters or more will be considered a carrier.
3.
By supporting floor slabs and beams. All load-bearing walls must be located strictly perpendicular to the location of the floor slabs. That is, the plates should rest on the walls with the short side.
Openings in load-bearing walls Once you determine which walls are load-bearing, you are aware of all the limitations associated with future redevelopment. Such a wall will not allow even an ordinary nail to be driven into itself under the picture.
And there is no need to talk about the arrangement of openings, niches, arches and partial demolition.
Both of these types have similar Constructive decisions and are made in the form of three longitudinal load-bearing and transverse walls, which support the longitudinal and, in general, are also load-bearing. Also, the walls are load-bearing, on which interfloor floor slabs are supported (short side). Usually these are longitudinal load-bearing walls. There is an option when the floor slab rests on reinforced concrete beam rectangular section. Which, in turn, rests on load-bearing walls or brick pillars. Under the beams, usually, interior or apartment partitions are installed. Bearing walls in a panel house In panel houses, the thickness of internal partitions ranges from 80 mm to 120 mm, made of gypsum concrete panels.
And, internal load-bearing walls are reinforced concrete panels with a thickness of 140, 180 or 200 mm. External load-bearing walls in a panel house have a thickness of 200 mm or more.
Bearing wall in the house - how to determine which walls are load-bearing? People who are going to redevelop an apartment or house must definitely find out which walls in their home are load-bearing. It is quite simple to determine this on your own, the main thing is to know exactly how to do it.
And in this article, I will definitely teach you this. I note that design features houses or apartments every professional interior designer must know. If he cannot even recognize which walls in the apartment are load-bearing, then this is no longer an interior designer, but an ordinary decorator.
Before we begin to consider our issue, I want to introduce you to the concept of "bearing wall". So, the carrier is called the wall that takes on the load of the elements located above it, including beams, floor slabs and walls. Load-bearing walls are not always used in the interior.
If there are sockets or switches on the wall, remember that there is wiring hidden inside the wall, which, if the room is not de-energized, can disable the power supply system and cause injury to the worker. If the house is old, there may even be a gas pipe in the wall.
Work carefully and, if possible, use a project where all these nuances are noted. Note! Never forget that you can not demolish a load-bearing wall, leaving the floor without support.
If professional skills allow you to take on the partial removal of the wall, do not forget to place a support in the resulting opening, which can eventually be hidden with false beams.
Most often, these are single-layer panels made of expanded clay concrete with a thickness of 300-350 mm or multi-layer consisting of two reinforced concrete panels thickness from 60 mm (external) and 80-100 mm (internal), separated by a heater. As a result, the load-bearing walls in a panel house have a thickness of 120 mm or more.
Bearing walls in a monolithic house With load-bearing walls in a monolithic house, not everything is clear. It is not always possible to identify them. In addition, they may not exist (for example, in monolithic-frame buildings).
In residential monolithic houses there are various designs. Such as, monolithic load-bearing walls, columns, pylons, beams, etc..
The standard thickness of walls and pylons is 200, 250, 300 mm. The diameter of the bearing columns can be more than 300 mm. The thickness of the internal walls, usually made of aerated concrete blocks, is from 200 mm.
So the thickness is not load-bearing partitions is less than 200 mm.
How can you tell if a wall is load bearing? It is customary to call load-bearing walls walls that take on the load from the floors and roof of the building and transfer it to the foundation. The thickness of the wall depends on the material from which it is made and what load it carries. Bearing walls can be internal and external. Internal load-bearing walls are usually thinner than external ones due to the absence of the need for heat-insulating layers. Designation of load-bearing walls on the plan The first way to determine which walls are load-bearing is to refer to the building plan. This may be an architectural and construction plan of a working project for a building or a floor plan from the BTI passport. Unfortunately, there is no standard for the designation of load-bearing walls on the plan. For example, in the architectural and construction plan, load-bearing walls are highlighted with separate hatching, and on the BTI plan, with thicker lines, but not always.
