In two- and three-storey country cottages one of the mandatory elements of the interior are stairs. Moreover, most often such structures are assembled with a turn of 90 degrees. The calculation of such stairs has some of its own characteristics. Constructions of this type, of course, must be made with strict adherence to certain technologies. A staircase with a 90-degree turn should be comfortable and safe to use.
What materials can be assembled from?
Currently, this type of stairs can be installed in cottages, made of:
- wood;
- metal.
Both of these varieties are quite popular among the owners of country houses. Wooden stairs are usually installed in buildings with a classic or "folk" interior. Such structures can have carved railings, be painted in different colors, etc.
Metal stairs made of galvanized steel are installed in housesdecorated in any of the modern styles. Designs with wrought iron railings, like wooden ones, are often placed in cottages with a classic design.
Two varieties
There are two main types of metal and wooden stairs with a 90-degree turn:
- regular with inter-march platform;
- with winders.
The first type of lifting structures is most often installed in spacious rooms. Such marches look as solid and solid as possible. Winder stairs with a 90-degree turn are mounted if it is necessary to save a little space in the room. Also, such structures in houses are often used as additional ones.
In addition to the usual wooden or metal, in private suburban buildings can be installed and modular stairs with a turn of 90 degrees. Such designs are convenient in that they can be easily adjusted to the layout and parameters of almost any room. In addition, such stairs are assembled very easily.
General design rules
When drawing up the drawings of stairs with a turn of 90 degrees, as well as ordinary ones, one should, among other things, take into account the following requirements of SNiP:
- the depth of the stairs should not be less than 28-30 cm;
- if desired, they can be made slightly protruding forward (no more than 2-3 cm);
- optimum step height - 16-25 cm.
The optimal width of the marches themselves is considered to be 90-100 cm. In the future, two people will be able to freely disperse on such a ladder - ascending and descending. Also, on such a march, for example, in the future it will be possible to easily move overall furniture. But if there is not too much space in the room where the staircase is installed, it is allowed to reduce this parameter to 70 cm.
Safety formula
The height of the railing is determined depending on the height of the people living in the building. But in any case, such a building envelope should not be below 90 cm.
When calculating the steps of a ladder, among other things, you should use the safety formula:
2 step heights + their depth=63 cm (human step).
To make the stairs in the house comfortable and safe, the angle of inclination of its marches should not be less than 30 and more than 40 degrees. The height of all steps in the stairs must be the same. Otherwise, it will be difficult to move on it. The only exception is the lowest level. It is allowed to make it a couple of centimeters higher than others.
The depth of the platform in front of the door should not be less than 1.2 m. In addition, such a structure must be protected with railings. The gap between the ceiling and the top step should not be less than 2 m.
Features of the calculation of stairs with platforms
Such rotary designs have:
- two platforms turned to each other at an angle in90 degrees;
- two marches.
Very often such stairs are installed, including in two-story cottages. In such designs, the length of the lower march can be very small. In any case, according to the regulations, it is impossible to assemble it with a height of less than 3 steps.
The upper flight in such stairs is usually quite long. But more than 20 steps should not be done in it. In most cases, the length of the upper flight in the home staircase does not exceed 10-18 steps.
Also, when designing a staircase with a 90-degree turn with platforms, one should also take into account the fact that the width of the latter should be slightly larger than the width of the march itself.
Calculation
When designing such a staircase, calculations are made for each of the marches. The space allotted for a 90-degree staircase in a house is usually limited. Therefore, when calculating such a design, it is important first of all to determine the number of steps of marches and the angle of inclination of the latter. In accordance with this, drawings are subsequently drawn up.
The angle of inclination is determined taking into account the space allotted for the march. If, with a ceiling height of 250 cm and a ceiling thickness of 20 cm, it will be equal to, for example, 320 cm, the calculation can be done as follows:
- 250 + 20=270 - determine the height of the upper platform;
- tgA=270/320=0.84 - slope angle tangent.
Next, we will use a special table and determine the actual angle of inclination. It will be equal to the optimal 40 degrees. Anywayspaces less than 320 cm sweat such a march should not be diverted. Otherwise, it will turn out too cool.
Knowing the length of the march, the number of steps, taking into account the optimal parameters of their height and depth, will be relatively easy to determine.
Features of winder ladder calculation
Such structures, like ordinary ones, of course, must also be safe and convenient to move. Winder steps in stairs with a turn of 90 degrees have the shape of a trapezoid. When designing such a structure, among other things, it must be borne in mind that the length of their short side should not be less than 10 cm. At the same time, in the middle of the march, such steps should have a depth of at least 20 cm.
Calculate stairs with a 90 degree turn of this type, usually not using formulas, since it is very difficult, but using special programs. This can be, for example, a graphical method or just a special online calculator.
How to choose the installation location?
Mount such structures, of course, most often in the corner of the room. In this case, one of the walls serves as a support for the steps of the lower march, and perpendicular to it - the upper one. Sometimes such stairs are installed and just next to one of the walls. In this case, the steps of the upper march are usually attached to the latter, and two supports are installed under the lower one.
Of course, there should be enough free space in front of the stairs mounted in the house with a 90-degree turn so that you can freely approach it. In smallat home, such structures are usually installed in the living room. In cottages of a large area, turning stairs can also be mounted in the halls. It is not recommended to install such lifting structures in living rooms, offices and children's rooms. And of course, the stairs in the house should be mounted in such a way that they do not offer a view of the interior of the bedrooms, showers or restrooms.
Features of the selection of materials for steel structures
Metal stairs with a 90-degree turn in the house are usually installed ready-made, assembled at enterprises. The only exception in this case are street structures of this type, for example, firefighters. Such stairs in private homes can be made with their own hands.
Supports for structures of this type are usually made from channels. As supports under the steps, pieces of a corner with a shelf of 40-50 mm can be welded to their vertical surface. This is how bowstrings are made.
To assemble the stringers, corners welded at an angle of 90 degrees are attached to the upper, inclined at an angle surface of the channel supports. Platforms in such stairs are most often made lattice. The same goes for stairs. Such structures are assembled from corners and rods of 8 mm. At the final stage, the platforms and steps of such stairs can be sheathed with a board.
Selection of material for wooden stairs
Such designs in country houses are usually assembled from thick boards. For the supporting part of the steps, materials of 30 mm are taken. For vertical elements that do not bear supports,use a 25 mm board. Fasten the steps to the march exclusively with bolts. Self-tapping screws are not used for this purpose. When using such materials, the steps of a wooden staircase with a 90-degree turn subsequently quickly become loose.
For railing handrails, a board 4 cm wide is usually used. This structural element of the stairs is attached to balusters made of timber. In this case, studs or bolts are used as fasteners. The latter are masked at the final stage with putty intended for wood with sawdust.
Installation of stairs with platforms
Constructions of this type can be assembled with a 90-degree turn both on bowstrings and on stringers. In the first case, the march supports will be simple wide boards with supports under the steps stuffed with bars on them. When assembling such supports, craftsmen use a building square. It is important to fill the bars on the bowstrings in such a way that after installation they are located strictly vertically.
Stairs on stringers are somewhat more difficult to assemble with your own hands. In this case, the boards are first cut according to a special template, depending on the depth and height of the steps. The latter are attached to the jagged grooves cut in their upper part.
Installation of a wooden interfloor staircase with a 90-degree turn is usually done using the following technology:
- supports are installed under the lower platform, and its frame is mounted;
- stringers or bowstrings of the lower march are attached to the platform;
- stuffing in progressriser and tread boards;
- supports are installed under the upper platform;
- strings or bowstrings are installed between the upper and lower platforms;
- stuffing of boards of the lower platform is being carried out;
- mounting the steps of the lower and upper marches.
At the final stage, the upper platform is sheathed. Next, the master proceeds to the installation of railings and fences. Balusters on stairs are usually installed at each step. If there are small children in the house, they should be placed more often. But at the same time, one should also make sure that the child subsequently cannot stick his head between the balusters and get stuck.
Features of winder structures installation
When assembling stairs with a 90-degree turn with turning steps, of course, certain technologies are mandatory. Lifting structures of this type also consist of two marches. But at the same time, they do not have a bottom platform. It is replaced by several winder trapezoidal steps. Usually, no more than 3-4 of them are included in the design of the stairs.
The simplest staircase to the 2nd floor of this type is assembled approximately as follows:
- departing from the wall to the estimated width, install a support under the lower march and winder steps;
- a second support is placed next to the wall;
- stringers are attached to the supports;
- mount the steps of the lower march;
- cut and install winder steps;
- mount stringers and steps of the upper flight.
Next, they sheathe the upper platform in front of the door and mount the railing.
Sometimes such stairs lead to the second floor or to the attic directly through the ceiling. In this case, at the first stage, an opening is cut in the latter. Stringers or bowstrings of the upper march in this case are attached directly to the floor structures. The parapet at such a staircase is installed on the top floor around the cut out opening. The height, like the railing of the march, must be at least 90 cm.
Stair decoration
Designs of this type in country houses usually look very solid. Ready-made metal stairs with a 90-degree turn most often do not need additional design. Plank structures of this type, after assembly, are additionally painted or treated with paintwork materials that preserve the visible structure of the wood.
In the latter case, experienced homeowners recommend using oil or wax to decorate stairs. Varnish for coloring such structures is not recommended by many masters. When using this material, the stairs will subsequently look cheap and not very stylish.
Also, carpets are often laid on the marches of such structures. The main decoration of wooden homemade stairs is usually the railing. Of course, it is best to make them carved. If there are not enough skills to perform such woodwork, you can simply buy ready-made turned ones in the store.balusters. Such items will not cost too much. And the stairs to the 2nd floor, if available, will look finished and as solid as possible.
