I wrote this article in April. And I put it aside in the hope that I would select illustrations, and perhaps break them into small blocks - more suitable for the format of this LJ.
But it’s already January next year - and I don’t know when I’ll do this.
That's why I'm posting it in its entirety, without illustrations, and if someone makes it to the end - tell me about it - I'll sign you up as a hero :)
Walls:
The walls of buildings are load-bearing, self-supporting and non-supporting.
What are the differences, how does it work and how does it manifest itself externally and in architectural aesthetics.
A load-bearing wall is a wall that supports the roof structure (or balconies, or any other load) - this is a wall that is a structural element. Part of a working structure. Like a post or beam in a post-and-beam system.
A self-supporting wall is a wall that does not carry anything additional - but has its own weight. That is, it bears its own weight, at least. The higher it gets, the greater the weight, the more similar its properties are to a load-bearing one.
A supportable wall is a wall that is supported not by what is below, but by what is on the side or above. That is, if it’s quite simple, it’s either a thing suspended on something, or nailed to a certain structure like a cladding. Such a wall has mainly an enclosing function - almost unrelated to the structure.
And now imagine a self-supporting wall made of brick or stone.
Ideally, stones and bricks lie flat in it, the load presses from top to bottom. The lower, the greater the load - it’s normal if the wall begins to expand and strengthen towards the bottom. Perhaps the wall will have a slope - like the walls of fortresses - narrower at the top.
If the wall is loaded and it becomes load-bearing (or a very large self-supporting one), this whole ideal picture will not work. Because a lot of additional loads will appear in the wall - which, although according to the design, should act strictly vertically - in reality - due to non-ideal density, due to loads that have some lateral shifts, etc. – a lot of stress will occur inside the wall. Of the obvious and understandable ones, all sorts of lateral moments will accumulate towards the edge of the wall, towards the corner of the building and the greatest load will be placed on the corner. Therefore, the corners seem to be strengthened and thickened in even simple buildings. Often it is necessary to remove excess load from window and doorways– to make the jumper easier. Sometimes during the construction process a certain tension accumulates that needs to be removed.
Load-distributing arches, etc. appear in the wall. things.
This is the picture for all load-bearing and self-supporting walls. The corners are reinforced, the masonry is complex so that there are dressings, the load accumulates towards the bottom and the wall thickens.
This is suitable for traditional materials - stone and brick. The same picture applies to modern blocks of all kinds (in fact, they are the same stones - just artificial). The same picture for reinforced concrete (monolithic) walls. Only there the internal stresses immediately go to the reinforcement and the strength is much higher than that of natural stone. But the principle is the same.
It’s a little different with wood, because you can’t install a distribution arch in it. But they don’t build from wood and very high or heavily loaded walls. But greater force is exerted on the angle, structures that lighten the jumpers appear - that is general principles are saved.
There is an architectural - aesthetic - expression for load-bearing and self-supporting walls. Just as an order is the ideal expression of a post-and-beam structure in stone and wood, so for a wall there is an architectural element - rustication. Rust is an image of large masonry blocks in a wall. Sometimes it is made of stone, sometimes it is purely decorative - made of plaster. When doing rustication, the architect tells us that the wall is load-bearing. Well, or at least self-supporting. The more powerful the rust, the more likely it is that it is a load-bearing wall. Making a pronounced rust on a wall that is clearly self-supporting is quite strange. Can. But less justified. And rustication (even exaggerated decorative) on supported panels is simply not an understanding of its essence and design in general.
Remember, we talked about whether the order on the Colosseum is decorative or not. (link)
So - in the Renaissance, almost the same combination of two structural systems on the facade. On the one hand, the wall is rusticated, that is, telling the viewer that it is load-bearing. On the other hand, pilasters appear, which seem to show that there is some kind of post-and-beam frame inside.
And researchers talk about the contradiction of these systems. Or - that the order on such facades is purely decorative.
Firstly - for some reason no one says that this could be a real carnassus - and the filling with a wall between is self-supporting (well, they don’t say - because this really is not so - at least in the Renaissance, although I think if you dig deeper - in the 19th century such mixed structures already existed - when the frame was connected to the wall)
Secondly – as with the Colosseum – these systems complement each other and are intertwined.
How it happens in this design: in its most primitive form - A leveling beam is placed on the load-bearing wall, which distributes all further loads evenly. On it, with a certain step, transverse beams are placed on which the ceiling is supported. If there were no beams, the beams would press pointwise and the internal loads in the wall would be more varied.
But nevertheless, the beams do not press evenly on every cm of the wall.
Secondly, what we said is that the corners bear a large load.
And thirdly, if the building has transverse walls - and there are more than 2-3 windows on the facade - then at the points of their connection with the main wall there is also a large horizontal load (and, by the way, a smaller vertical one - if the transverse wall is also load-bearing, but it is usually self-supporting)
So the appearance on the facade of some vertical elements- semi-columns, pilasters - it seems that a post-and-beam system could be justified. Of course - if they express internal layout buildings and repeat interior walls– this is doubly justified. But often you have to cheat somewhere and add extra ones - for an even step or for the beauty of the facade.
Still call it clean decorative elements- it is forbidden. They are tectonic.
Working in monolithic reinforced concrete, we can absorb all these loads with reinforcement. And make a perfectly smooth, even wall. However, this flat wall will only be a decoration – it will not reflect the internal work.
Perhaps, in order for a reinforced concrete wall to be a truly pronounced structure, its reinforcement should, as it were, “shine through” - like the veins on a person’s arms or read like a skeleton. Seeing a living creature, we cannot draw its skeleton. But we can completely imagine the main supporting structure inside. However, the principle of operation of a reinforced concrete wall is not very different from stone (yes, stronger, yes, more complex things can be made, larger protrusions and lintels, but the principles are the same - the load acts from top to bottom)
So - at the beginning of the 20th century, designs appeared that made it possible to simply hang a wall on them. And make any wall. Glass. Made from lightweight foam, etc. Loose walls appear.
It must be said that in architecture, a load-bearing, self-supporting or self-supporting structure is a very important criterion. They are often sharply different, painted in radically different colors - like black and white half-timbered or white-colored classicism.
Therefore, if the wall is unsupported, it is very important to show and emphasize (well, because we remember that tectonics is the basic principle of architecture - and exceptions only confirm the rules)
That is, there are two options - to identify and aestheticize modern hanging structure. Or deliberately abandon the principle of tectonics - and create something completely different. What do deconstructionists do? But this must be done a) masterfully b) clearly. Like a bright trick, a theatrical performance. Or pure decorativeness - with bright color. Ideally, an elegant joke. So far, I don’t see any application or path for this in mass architecture. This is a separate conversation, of course...
So - if the wall is unsupportable - then it would be good to identify and emphasize this. How can this be done?
1. identify and show load-bearing frame making the wall almost invisible. For example glass. So at Foster - in a cucumber. The frame has been revealed. Glass is portable. By the way, Koolhaas too (despite the fact that he is a deconstructivist and, in general, the Chinese skyscraper does not come from the design). Any buildings “just pieces of glass” do not meet this criterion, because the frame is not revealed.
2. develop a decorative expression that the wall is supported not by what is below, but by what is on the side (or suspended). It could be rivets. (or any other fastenings based on the principle - nails, screws, etc.) These could be some kind of latches around the perimeter - similar to the principle of glass in frames. Such options were made by Otto Wagner for cladding (by the way, this can all concern simply decorative cladding walls) - this is not rustication - these are panels “nailed” to the wall or frame. IN modern architecture This option has not been developed at all.
3. Look for the aesthetics of the curtain walls in the old curtain walls. For example, in skins that were stretched over the frame of yurts, etc. dwellings... To go by demonstrating that the wall is flexible and cannot hold without an internal supporting frame - it means it is there. Perhaps the time has not yet come for this - and not yet modern technology flexible fabric for walls. Especially something involving windows. Although I think that this is quite possible. But this is a question for technologists... partly this is expressed by Zaha Hadid - in her flexible walls.
one of the most widespread types of walls. The task of load-bearing walls is to withstand the load from the floors and roof, as well as to provide the necessary thermal insulation. For the construction of load-bearing walls, materials with sufficient strength are used: natural stone, brick, cinder block, concrete blocks, monolithic concrete etc. However, the greater the strength of the material, the greater its density and, accordingly, the lower its resistance to heat transfer. Therefore, the thickness of load-bearing walls made of brick, natural stone or heavy concrete, sufficient for the strength and stability of the wall, is often insufficient to provide thermal insulation according to the latest thermal engineering standards. If earlier thickness brickwork outer wall 51 cm for some climatic regions was considered sufficient, now even 77 cm of brickwork thickness on the outer wall is not always enough for the same areas. Therefore, external load-bearing walls increasingly they are made not from one material, but from at least two. In this case, the first material provides the necessary strength and stability, and the second provides thermal insulation. IN low-rise construction external load-bearing walls can be made of less durable materials, such as cinder block, lightweight, porous and cellular concrete.
Self-supporting walls
are made in frame buildings, often self-supporting walls are called enclosing structures. In frame buildings, the frame is designed for the load from the floors, overlying walls and roof, so self-supporting walls are subject to the load only from the own weight of the material from which the self-supporting walls are made. This allows you to use almost any material that can withstand wind load and impact for the construction of self-supporting walls. atmospheric precipitation. Self-supporting walls can be brick and stone and made of heavy concrete, but for the reasons given above, for the construction of self-supporting walls, materials that have the necessary resistance to heat transfer are usually used. In addition, wall materials must have good frost resistance and low water absorption. The more water absorbed by the wall material, the worse the thermal insulation will ultimately be and the faster the destruction of the material may occur when it freezes in winter time absorbed water. But as a rule, less dense materials, due to their structure, have quite high water absorption and therefore often require additional protection.
Well, now let’s take a closer look at the most commonly used
Wall materials:
Building materials used for the construction of walls can be classified according to various criteria: by origin, by production method, by strength, by weight, by thermal conductivity, by size, by ease and speed of installation, by accessibility, by aesthetics, by environmental friendliness, by price etc. Each of the above signs is certainly important, so choose the most suitable option when building your own home is not so easy. One of the most revealing in my opinion is the classification of wall materials by size and weight, since most construction sites of private houses have a low level of mechanization, which means that most loads are lifted manually. Further, materials for walls are considered precisely from this position, and along the way they are given brief characteristics materials according to other specified characteristics.
By size, wall materials are divided into:
Small-piece wall materials.
Small-piece materials are those that can be laid relatively easily by hand. As a rule, the weight of one element does not exceed 20-30 kg. Accordingly, wall elements made of denser materials are smaller in size than elements made of less dense materials. To small pieces wall materials include:
Natural stone
obtained from rocks.
Mud and earthen walls are also erected using formwork, but such walls have become very rare lately.
As we can see, despite the fact that people have long since descended from the trees, emerged from caves and climbed out of dugouts, the material for the walls is still wood, stones, and sometimes clay. So don’t believe in genetic memory after this...
In the previous article, I talked about how to correctly calculate the foundation for a brick house, well, today we’ll look at diagram of the foundation itself and determine under which walls it is needed. Also, in this article, I will talk about how to prepare the site and correctly mark all the walls under which concrete will be poured.
About which foundation for a brick house is better, we have already figured it out, and, in our case, the choice fell on the tape one, but in order not to repeat ourselves, we will immediately proceed to the scheme.
Foundation diagram for a brick house
In order to decide on a scheme strip foundation, let's take a look at the layout of the rooms in the house.
As we can see, there are a lot of walls in the house, and pouring a monolithic reinforced concrete strip under each of them is impractical, since in this case, the cost of the foundation will at least double.
In most cases, it is sufficient to construct a foundation only under load-bearing and heavy walls. And thin and relatively light partitions can be erected on a rough concrete (reinforced concrete) floor.
Load-bearing and self-supporting walls
Now let's take a look at the diagram of the foundation itself, and then I will explain on what principle the internal load-bearing walls were chosen.
Bearers walls No. 1 and No. 2 designed to more evenly transfer the load from the roof to the foundation. Their additional purpose is to prevent significant “sagging” of wooden ceiling beams, since there is a very large distance between the opposite external walls.
The diagram below shows how the ceiling will be located wooden beams, on which the entire roof will rest.
In this regard, these walls will be at least 20 - 25 cm thick, which means they will already have a relatively large weight. In addition, the roof will still rest on them, and the lack of a foundation under such walls is fraught with consequences.
Wall No. 3 separates the garage from the main house. No matter how well the garage is heated, it doesn't matter winter period, this will be the coldest room in the house due to the constantly opening gate.
So, in connection with the above, in order to retain heat in the house, it was decided to make this wall thicker, the same as all the external walls. Although it will be practically self-supporting, it will still have significant weight, which implies the presence of a sufficient foundation under it.
The remaining walls separating rooms and other rooms from each other can be made into thin partitions, the load from which can be easily withstood by a reinforced concrete floor poured onto the ground. In other words, the foundation under self-supporting thin partitions will not be poured.
Foundation thickness under load-bearing walls
In the previous article, in which we calculated the foundation for a brick house, I said that the entire monolithic reinforced concrete strip will be 40 cm thick, despite the fact that the total thickness of the external walls will be about 50 cm.
Below in the diagram you can see how a wall 50 cm wide will be placed on a base 38 cm wide. (Read in the previous article why the foundation is 40 cm and the base is 38 cm).
The diagram is quite approximate and, accordingly, does not respect proportions. Parameters such as thickness sand cushion, monolithic thickness reinforced concrete slab etc. - we will look at it later, in the relevant topics.
Since a rough reinforced concrete floor will be immediately poured on top of the base, there will be no “sagging” of the wall, and for strength and support on the ground, a foundation base of 40 cm will be sufficient. This will save on the foundation.
Site preparation and foundation marking
Your main enemy in the process of marking the foundation is grass and uneven ground, which is responsible for most of the errors in measurements. Therefore, before marking, the future construction site was cleared of tall vegetation (grass, bushes, etc.). In most cases, to clean and prepare the area, it is enough to use a trimmer (gasoline or electric scythe).
There was no need to level anything, since construction site and so it turned out, more or less even.
Of course, some time and effort were spent on cleaning, but this made it possible to more accurately mark the foundation and subsequently made the work much easier and faster.
It is worth adding that in our region the cleanliness of sites is monitored, and abandoned and overgrown ones entail a significant fine to the owner.
Marking strip foundation
The markings were made using a tape measure, a cord, pegs made from d8mm reinforcement, and a hammer, with which these same pegs were driven in.
First of all, we determine the location of the house on the site. Schematically it looks like this:
Before marking the location of the house on the site, carefully study the documents permitting construction. The basic rules for locating the house, regarding the red line and neighboring plots should be spelled out there. The diagram has a red line at the bottom.
Now, you need to mark the rectangular perimeter of the entire house. Below in the diagram, the perimeter is indicated by red dots.
Only after this can you begin marking the foundation. Now you have something to start from and marking all the walls will not be difficult.
Order and technology of precise marking the foundation for a house, without the use of expensive tools and devices, is very simple and described in detail in one of the previous articles. In our case, it was produced in exactly the same way, so we will not dwell on this.
After accurately marking the perimeter of the house, checking that the sizes of the diagonals match, we marked everything external walls, and then internal ones. Thus, everything was ready for the next stage of construction of our future home.
It is worth adding that the marking was done by two people for about 2 hours, since the house is huge with a lot of corners. By the way, marking can be done by one person, but it is quite long and difficult to do accurately.
Well, that’s basically all there is to it house foundation diagrams, as well as everyone preparatory work. Well, in the next article we will proceed directly to the construction of the foundation itself brick house.
9. Walls of civil buildings. Basic requirements. External and internal walls, load-bearing, self-supporting and non-load-bearing walls, partitions.
Walls- These are vertical fences that separate rooms from the external environment and from each other. The walls must withstand the loads placed on them, ensure a constant temperature in the room and make it soundproof. In construction, depending on their purpose, walls are classified into external and internal. Depending on the material used, walls are made of artificial materials (concrete, brick, asbestos-cement) and natural (limestone, shell rock, tuff, wood). Depending on the perception of loads from the building, the walls can be self-supporting, self-supporting And non-structural. Bearers walls take loads from other parts of the building (floors, roofs) and, together with their own weight, transfer them to the foundations. Self-supporting The walls rest on foundations, but they carry the load only from their own weight. Non-load bearing(curtain) walls are fences that rest on each floor on other elements of the building (frame) and support their own mass within one floor.
The walls of civil buildings must meet the following requirements: be strong and stable; have durability corresponding to the class of the building; correspond to the degree of fire resistance of the building; be an energy-saving element of the building; have heat transfer resistance in accordance with thermal engineering standards, while ensuring the necessary temperature and humidity comfort in the premises; have sufficient soundproofing properties; have a design that meets modern methods of constructing wall structures; types of walls must be economically justified based on the given architectural and artistic solution, and meet the capabilities of the customer; material intensity (material consumption) should be as minimal as possible, since this greatly helps to reduce labor costs for the construction of walls and overall construction costs.
Partitions are called relatively thin walls that serve to divide the internal space within one floor into separate rooms. The partitions rest on the floors on each floor and do not carry any load other than their own weight.
PARTITIONS. Partitions must be soundproof, nailable, durable, and stable. Partitions are installed on the floor structure before flooring is laid. In places where partitions made of combustible materials adjoin stoves and chimneys, brick cuts should be arranged along the entire height so that the distance from the partition to the inner surface of the stove or chimney is at least 40 cm. FRAME. GYPSUM PARTITIONS. BRICK PARTITIONS. Brick partitions are laid with a thickness of 1/2 brick (12 cm). The basis for partitions can be concrete preparation under ground floor floors or reinforced concrete floors. Due to their significant weight, brick partitions should not be used on wooden floors. A non-load-bearing wall, or partition, can only be internal.
