The houses under construction today are so diverse that the structures being built sometimes take on a completely bizarre look. Architects especially love to experiment with roofs that are both flat for picnics and transparent for winter garden, and in the form of a fancy flower.

However, the most practical remain the most simple options such as a gable roof. Consider the device rafter system gable roof in this article.

With the help of this structure, a large attic space is created that does not require special insulation, therefore it is very popular in the construction of residential buildings.

In addition, it is easy to install, unlike, for example, a four-slope one and does not require large investments during installation.

A gable roof is a structure of two rectangular surfaces, the upper parts are connected to each other, and the lower parts are supported by the walls of the house.

Thus, two triangular parts at the ends - pediments - remain uncovered at the roof. These parts are either deaf, or used to enter the attic.

It is very convenient to use the resulting attic for an additional room that can be used in warm weather. And if you make an effort and insulate it, then you will get a full-fledged room suitable for life in winter.

Main parts rafter roof are visible in the figure below:

• Mauerlat, which holds the entire structure on the walls;
• rafters that form the roof itself;
• the lathing on which the roof covering is attached;
• ridge girder connecting two roof planes at the top;
• struts and struts, additionally reinforcing the roof.

The structure of the rafters can be of two types:

• hanging;
• inclined.

Hanging rafters are fixed at only two points - on the ridge and on the walls. Therefore, their structure is subjected to two types of load - compression and bending. In addition, inclined ones, in their middle part, rest on intermediate supports, which significantly reduces bending loads.

Most effective way the device of the gable roof rafter system is a combination of hanging and inclined rafters. This combination increases structural strength and reduces material consumption.

Due to this simplicity of construction, a gable roof has a number of advantages:

• simplicity of execution and repair in case of damage;
• low cost of work and materials;
• high wear resistance and strength;
• low probability of leaks, since such a roof has no joints different surfaces, the design is almost one-piece;
• the possibility of arranging a full-fledged living area in the attic.

Payment

Before installing the rafter system, it is imperative to calculate it. This requires perseverance and attentiveness, all calculations must be double-checked a couple of times. Staying in the midst of work without the necessary building materials, or, conversely, buying too much will cost you much more.

If the installation of a gable roof is carried out according to a detailed design, it is necessary to select all the elements of its structure with the designation of the size and quantity of each position. Using the principles of rational cutting, add up the volumes by:

• types of lumber (lm);
• vapor barrier material (m 2);
• roofing (quantity per piece, m 2);
• insulation (m 2).

For the convenience of calculations, it is best to calculate separately the area of ​​each simple element separately, and then add up the results.

For clarity of calculations, we will calculate several roofing options for houses of the same length of 8 m and a width of 4, 5, 6, 7 and 8 m. Let us determine that the angle at the top of the roof (at the ridge C) will be the same for them - 120 °. The angles of the roof slope at the attachment points to the Mauerlat (A and B) will also be the same in this case - 30 ° each.

We start by calculating the height of the roof H, it is calculated by the formula

The length of the rafters AC according to the theorem right triangle, is calculated as half the width of the house AB, divided by the sine ½ of the angle α at the apex

AC = ½AB / sin (α / 2) + 0.5 m

To the obtained value, it is required to add the length of the eaves overhang, which ranges from 0.5 to 0.8 m.

The total amount of material that we need to make the rafters is calculated as the product of the length of one rafter by the required number of rafters.

We choose the rafter pitch from the standard range of 0.6-1 m.

For our calculation, we determine that the pitch of the rafters will be 0.7 m.

In the area where there is elevated level accumulation of snow, it is necessary to strengthen the rafter system - to install a solid crate and paired rafters.

So, from the results obtained, we will compose a table, studying which, one can understand how the width of the building affects the amount of materials required for the construction of the gable roof rafter system.

Please note that the formulas given are used to calculate the exact size of the materials. Planks, tiles, slate and all other materials are available only in certain sizes. You are unlikely to buy boards for rafters 5.12 m long. Perhaps the closest size will be 7 or even 8 m, and you will have to saw off the excess.

When calculating and buying material, be sure to take into account the fact that it is on sale only in fixed sizes that do not match yours, and some of it will go to waste.

Of course, it is better to entrust the final calculation of the amount of required materials to specialists, but using the proposed scheme, you can preliminarily determine what costs await you.

Mounting

There are two ways to install the rafter system:

• mount the rafters directly at the installation site;
• mount the rafter pairs (truss) on the ground and lift them up.

The first method requires less physical effort, and the second allows you to use a wide construction site and reduces the risk of falling from a height.

A "farm" is a pair of rafter legs connected to each other in accordance with the project.

Required tool

How you prepare for the work directly depends on how quickly and efficiently you will carry it out and how comfortable it will be for you to work.

For work on the construction of the rafter system, you need:

• axe;
• hammers, different weight and type;
• nail puller;
• screwdriver;
• hacksaws or chainsaw;
• Bulgarian;
• drill with a set of drills and a countersink;
• long tape measure;
• building level and plumb line;
• pencil, marker for marking;
• construction cord;
• fastening accessories: corners, strips, nails and screws.

Making a template

To make it easier to connect the rafters into trusses and keep the same dimensions, a template should be made according to which the rafters will be cut and connected. To do this, use two long boards, connecting them in the form of the letter A in exact accordance with the dimensions future roof... Then each rafter pair is adjusted to this template and fixed, gradually forming the roofing system.

The rigidity of the structure being erected directly depends on how high-quality and firmly the rafters are fixed to each other. To increase the strength of the joints, use special metal plates.

Fastening the rafters to the Mauerlat

The most important element in the installation of the roof is the fastening of the rafters to the Mauerlat.

It can be done in two ways:

• tough;
• sliding.

Rigid fastening of the rafters to the Mauerlat eliminates any impacts on the resulting connection - shifts, turns, bends. Such strength can be achieved by fastening the rafters with support cuts, bars, metal corners, using staples and nails. Additionally, you can fix the rafters to the wall with anchors or wire.

The sliding fastening of the rafters to the Mauerlat has two degrees of freedom. This mount is recommended for roofs wooden houses... At the same time, the rafters are able to move along their longitudinal axis. To do this, they are placed in special cuts of the Mauerlat, which exclude lateral movements, but allow them to move up and down. Such restraints can also be made from two large restraining nails or a special plate.

Installing trusses

The trusses are installed at the ends of the building, and a cord is pulled tightly between them. The cord must be strictly horizontal, which is controlled by the level. If one of its ends is higher than the other, then the farm to which it is attached will need to be lowered slightly.

To eliminate the sagging of the rafter system from the load, it is required to reinforce the middle rafters with special struts.

The rest of the rafters are installed at the level of this cord with the required step and secured with braces, retaining beams and other methods provided for by the project.

Before calculating the stairs, you need to consider the main types of these structures.

Simple staircase design: 1 - channel; 2 - corrugated metal steps; 3 - steel "filly"; 4 - welding places; 5 - step mounting brackets.

Straight stairs are the most simple form this design. It is convenient to navigate along it, including carrying heavy things. If the house has high ceilings and the ladder consists of more than 18 steps, then it is recommended to arrange an intermediate platform in the middle of the structure. The disadvantage of this type is the large occupied area.

Two-flight stairs have an intermediate platform and can be angular or U-shaped. Although this type is characterized by the presence of an intermediate platform, due to its configuration, the structure fits well into almost any room, including not so big size... In the U-shaped type, the width of the intermediate platform must be not less than the width of both flights, which must be taken into account when calculating the stairs.

Winder stairs are a structure of two or more flights, instead of intermediate platforms in which special rotary (winder) steps are used. Transient species require a minimum free space and fit easily into confined spaces... The disadvantage of this type is the complexity of the design, complex scheme stairs, since all winder steps are different, have their own individual sizes... And the stringers and railings are also distinguished by complex curved shapes. Calculation of stairs of this type is also quite complicated.

A spiral staircase is the most economical type. The most optimal radius is 80-90 cm. The disadvantage of this design is less convenience when moving along it, a steep climb, and it is very difficult to lift heavy and bulky things along it. The spiral type is distinguished by its complexity of design, the calculation of the stairs is difficult, but they have an attractive and spectacular appearance.

This type of ladder, such as "samba" or "goose step" is also distinguished by its economical configuration. The main hallmark is a diagram of a ladder, namely half steps, which set the sequence of a step in strict adherence. Depending on the position of the first step, the ascent will always start from one specific leg (right or left). This type is distinguished by its steep climb. Most often, such a staircase scheme is used as an auxiliary one, for climbing to the attic, in extremely limited space.

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Calculation of stairs during design

If it is necessary to install a staircase in the house, then many issues will have to be resolved. And not only with regard to the type, materials, but also the need to calculate the stairs.

After all, it's not enough to come up with a model, you need to correctly enter it in the room, taking into account the area and height of the ceiling.

The first indicator that is needed to calculate the stairs is the height from the floor of one floor to the edge of the floor of the next floor. If the house is still rough finish, then it is necessary to take into account the thickness of the finishing layer with all substrates, leveling materials, etc.

After that, the number of steps is calculated. For this, the height of the room must be divided by the desired step. Upon receipt fractional number the calculation of stairs requires an adjustment in the direction of decreasing or increasing the number of steps, according to which the step will increase or decrease.

Each ladder also has its own constant size: this is the width of the tread, the size of which is taken in the range from 130 to 225 mm. The parameter shows how much length must be left to accommodate the structure. This distance is obtained by multiplying the tread value by the number of steps. It is also necessary to add 80 mm to the resulting number, technical dimension, i.e. the distance allotted for the lunge of the first stage and part of the upper module. When building a staircase, calculating its width, it is necessary to take into account the dimensions of the room, and how much space can be allocated for the structure device. The value is calculated according to the free area.

It is worth considering that if the staircase does not fit a little into the dimensions of the room, you can use one trick. If the thickness interfloor overlap is more than 30 cm, then it is allowed to indent down by 15-17 cm. The remaining distance is quite enough to secure the structure.

The most important role the dimensions of the opening play in the choice of design. If it is too small (for example, width - 700-900 mm, length - 1100-1600 mm), then only a "goose step" staircase can be entered into it.

Also, the diagram of the staircase, its shape depends on the desired step of raising the step and the width of the tread.

It is worth noting that the smaller the step height, the more steps, modules, balusters, railings will be needed, respectively. And the longer the stairs will be.

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Formulas for calculating stair elements

There are several formulas for calculating stairs that will allow you to design the correct structure.

Among them, the ratio of the riser height a to the tread width b, which can be calculated using three formulas:

• convenience formula: b-a = 12 cm;
• step formula: 2a + b = 62 (60-64) cm;
• safety formula: a + b = 46 cm.

The optimal ratio is 17/29, however, the following deviations are allowed: tread: 26 ≤ b ≤ 32 on average 29, riser: 14 ≤ a ≤ 20 on average 17.

The height of the rise h depends on the height of the room H and the thickness of the floor D: h = H + D. The number of steps n is calculated by the formula: n = h / a.

The length of the projection of the stairs to the floor plane l depends on the number of steps n and the width of the tread b and is calculated by the formula: l = b * n.

Next, you should determine the steepness of the stairs k. It depends on the lifting height h (height from the floor of the lower floor to the floor of the upper one) and the length of the projection of the structure onto the floor plane l. The slope is calculated by the formula: k = h / l.

Branching algorithmic structure is a structure consisting of two or more branches. The simplest version of it is binary branching (alternative, structure if-else, if-then-otherwise ). Its block diagram is shown in Fig. 25.1 a, and pseudocode with the following text:

…
if<логическое выражение>
then Branch A
otherwise Branch B
all
…

When it is executed, the logical expression is evaluated first. If it matters true , then branch A is executed, but if Lying , then branch B. Each branch can include one or more elementary actions. If a branch includes several actions (operators), then they must be combined into one compound action using service words start and end (see an example of an algorithm for solving quadratic equation). In the block diagram, a binary branch is depicted as a diamond-shaped graphic element alternative ... Transition directions can also be marked 1 or Yes (true) and 0 or No (Lying).

A special case of binary branching is a traversal in which the branch does not otherwise contain any action - empty.

…
if<логическое выражение>
then Branch A
all
…

The block diagram of this structure is shown in Fig. 25.1 b.

Rice. 25.1. Block diagram of structures "branching" (a) and "bypass" (b)

As a logical expression can be used can be used expression of attitude (condition) in which two expressions are compared by signs of a relation, for example, k = 0 or i or sin (x + π / 2)> = exp (-2y) -1... In more difficult cases logical expressions use the signs of logical operations: inversions not, disjunctions or or conjunction and... For example, not (k = 0 and ((i = exp (-2y) -1)))... When constructing complex logical expressions, it is necessary to use the rules and laws of Boolean algebra.

Multiple branching is a structure that branches into more than two branches. From the point of view of theoretical programming, it is redundant, since it can be implemented using binary branches. But almost all programming languages ​​have an operator that supports this structure, so let's look at it using the example of branching into three branches (block diagram in Fig. 25.2). Branching is controlled by a selector expression s, which can take the provided values a, b and c... If s = a, then the branch A, if s = b, then the branch B, and if s = s, then the branch WITH... The structure also has a branch X, which will be executed if the selector s takes a value not intended for the execution of the previous branches.

In fig. Figure 25.3 shows the implementation of this structure using binary forks.

Rice. 25.2. Block diagram of multiple branching

Rice. 25.3. Implementing Multiple Branching with Binaries

In pseudocode, multiple branching is written as follows:

choice
for s = a: Branch A
for s = b: Branch B
for s = c: Branch C
otherwise Branch X
all

Aluminum stairs are a structure of two racks connected by steps. An alloy of aluminum and silicon is usually used as a material of manufacture. This ensures high strength of such products. These ladders usually have different types constructions. It depends on the purpose of their application.

Four-section ladder - a tool for a wide variety of jobs

Types of aluminum stairs

Aluminum stairs according to the type of construction, they differ into one-, two-, three- and four-section. They have from 6 to 25 steps and are used for various purposes. While doing household work a stepladder that can handle most tasks comes in handy. The most common are ladders with the main part of metal, and the legs with steps are made of plastic.

In addition to household, the following types of structures can be distinguished:

Household stairs, as well as dielectrics and most transformers have many additional parts. They increase the safety and reliability of structures.

Types of stairs

Majority modern stairs turn out to be indispensable for operation at height, both in domestic conditions and at industrial enterprises. On this basis, they are divided into used in everyday life and professional.
The first type of products is made of aluminum, has high lightness, simplicity of design and must meet important requirements- durability, ease of transportation and installation, safety, undemanding storage conditions.

Professional designs have a number of characteristic features determining the scope of their application. For example, transformers are highly functional and are often used as a platform. Telescopic ladders are very compact and allow for the same amount of work as many three-section structures.

Design features

The maximum weight of the user of aluminum ladders varies - from 100 to 150 kg. With more high rates we can say that the design is professional. The working length is measured to the last platform or step. Professional constructions are up to 15-20 meters high.

Please note: sometimes the working length can be considered the height from the floor to the penultimate step, and 120 cm is added to it. It is better to check this question with the seller.

Single-section ladders

Three-section staircase - like a stepladder, only better

This is called an attachment structure and requires vertical support. To avoid ridiculous injuries during use, the legs must be well fixed. Distinctive features of attached structures are:

1. Wide application at home. Indispensable for light repairs, work in the garden, in the country. She allows without special efforts harvest and sawed off dead tree branches.
2. A one-section ladder is not superfluous when carrying out installation and construction work. Frequent use is due to ease of use - you just have to lean against the wall and securely fasten.
3. Choice. When buying an attached one-section ladder, the main parameter that you need to pay attention to is the height. Not only the functionality of the product depends on it, but the cost. On construction market there are different options: 1.5 to 5.6 meters long.

The material of manufacture (aluminum with duralumin, magnesium, silicon) is highly durable and long term service. Although single-section aluminum side ladders are still inferior to their improved versions.

Two-piece structures

The features of these ladders include: anti-slip steps, a variety of models (from 3 to 25 steps) and the possibility of two-way climbing. The maximum step-ladder height is up to 13 meters. The advantages of the ladder include corrosion resistance, unlimited operating conditions, low weight and compactness.

Two-section aluminum ladders have 2 types of construction: folding (ladders) and sliding. The latter are distinguished by the fact that one part of them protrudes from the other. The recommended load does not exceed 150 kg. Such structures are distinguished by high functionality and convenience, they can be used as attachments.

Any staircase, the same two-section aluminum, must first of all have the necessary functionality.

Three-section stairs

With the help of such a ladder, you can easily paint ceilings and places inaccessible from the floor.

You can use such a ladder in the form of a step-ladder, an attached structure. It has transverse braces between the legs, which provides the greatest strength. The aluminum profile allows the structure to be used with a load of up to 150 kg.
It is a product for household use. In the form of a ladder, it usually reaches a height of 6 meters. As a stepladder it can be used at a height of 5 meters.
When folded, such a staircase most often has the following dimensions (height, width, depth): 2.5 * 0.4 * 0.15. The approximate step width is 25 mm. The plugs are made of two-component plastic.

Four-piece products

Ladders with 4 sections are called transformers. They are the most functional and are used both as ladders and in the form of attached structures. Can replace scaffolds.

main feature such stairs are a relatively rare use. They have several parts connected by hinge mechanisms. The advantage is compactness when folded, as well as high stability and reliability in use.

Distinctive features of such structures are high functionality, large working length, the ability to withstand a heavy load - up to 150 kg, the possibility of using the principle of a side ladder, the maximum simplification of complex construction work.

The small weight of the product makes it easy to carry during work. It is also convenient to be able to quickly change the height. work surface.

Advantages of the 4-section step ladder

Due to its design, the four-section ladder can cope with huge amount tasks and has a number of advantages:

• compactness;
• high resistance to different types surfaces;
• the presence of a special relief;
• high strength of the product, provided by the aluminum profile;
• convenient to store and transport;

The ladder components, due to their peculiarities, allow the ladder to withstand significant operational loads. Suitable for both hobbyists and professional builders.

The cost of aluminum stairs

Now let's turn to the most interesting question: how much do such constructions cost? Aluminum ladders, depending on the characteristics, have a large variation in cost. Below are their main types.

So, prices for structures with only 2 sections:

• two-section ladder (maximum length 314 cm, weight - 6.4 kg) aluminum - 5 thousand rubles;
• the same construction, which has a length of 427 cm, costs about 6.3 thousand rubles;
• a universal two-section ladder with a working height of 687 cm will cost the buyer 11 thousand rubles;
• sliding structures can cost from 4.5 to 12 thousand rubles;
• universal ladders can be purchased for 5.5-12.5 thousand rubles.
• three-section ladders cost from 3.5 to 11 thousand rubles, and prices for structures consisting of 4 parts vary from 5.5 to 12 thousand rubles.

As can be seen from the prices, four-section products are distinguished not only by high performance characteristics but also availability.

How to choose the right ladder

Before buying a specific product, you should decide on its necessary characteristics and the tasks of operation.

Study your ladder thoroughly for build quality before purchasing

At the right choice a ladder will certainly help you achieve lofty goals. For example, for cosmetic repair apartments will do the usual side-by-side option. First of all, consider the areas of application staircase structures:

• repair and construction works;
• household needs;
• electric installation work;
• use in large libraries;
• work in the garden.

It is necessary to select the required working height, maximum load and pay attention to the availability of special mountings.

The telescopic crown is a design of two parts: primary and secondary. It is mainly used for fixing. The primary part is a metal cap. The secondary crown is fixed to the prosthesis frame. When the two parts are joined together, a sturdy structure is formed. With its help, you can form a strong attachment of the prostheses, which at the same time can be easily removed.

Varieties of telescopic crowns

This mechanism was first tested in Germany at the beginning of the last century. The telescopic crown owes its name to its resemblance to a telescope. Its component parts move relative to each other in the same way. For practically centuries-old history this design managed to prove its practicality, ease of use and good aesthetics. These days, telescopic crowns can be excellent alternative option prostheses on implants.

There are two types of this design - cylindrical crowns and conical crowns. Basically, they differ in appearance. The earliest examples of telescopic crowns were made by artisans with cylindrical walls. They are characterized by a fairly snug fit. Today, such a design is advisable to use only among patients with absolutely healthy gums.

The telescopic conical crown is an improved version of the cylindrical crown. Its main advantage is considered to be the absence of the influence of errors that are possible at the manufacturing stage. This design does not allow for skewing or jamming when fixing the prosthesis. The main disadvantage of the improved system is the ability to detach the crowns upon contact with food.

Benefits of telescopic crowns

What kind positive sides can be noted in the application of this design?

1. The chewing load is evenly distributed over all teeth and gums.
2. Lack of influence on diction and bite.
3. Possibility of installation on implants.
4. Long service time.
5. Easy to use and maintain.
6. Keeping the tooth healthy for a long time.

These are not all the advantages of telescopic crowns. Everyone can note for themselves the positive aspects of using the design.

Disadvantages of telescopic crowns

Among the main disadvantages of this design are a long manufacturing period and high cost. However, the negative aspects are fully compensated for by the above advantages of crowns.

Installation indications

The use of telescopic crowns is advisable in the following cases:

• the presence of periodontal disease and loose abutment teeth;
• there is no financial ability to install implants;
• too few teeth for clasp dentures.

The need to use this design is still determined by the doctor.

Telescopic crowns: manufacturing steps

The production of the structure described in the article today is possible in two ways: stamping and casting. The first method is considered to be the simplest. However, when using casting, it is possible to obtain a more attractive appearance product through processing with modern materials.

Manufacturing of telescopic crowns begins with turning the patient's teeth under interior constructions. Then the specialist takes impressions and sends them to the laboratory. There, technicians are already making models from them and making caps. It is very important to check the parallelism of the walls of the abutment teeth so that the structure fits accurately. After trying on the caps, a plaster cast is formed from them for casting the future model. The external crown is made taking into account a gap of 0.5-1 mm. An external structure is already being made on the basis of the resulting print.

Cost and service life

Telescopic crowns are considered relatively expensive. Its cost can vary from 5 to 11 thousand rubles. If we talk about complete prosthetics, then the final price will depend on several factors simultaneously (the material used, the number of abutment teeth, etc.). It is not possible to name it exactly.

On telescopic crowns characterized by a short service life - no more than 10 years. To increase it, it is necessary to periodically visit a doctor and monitor the operation of the structure.