Greetings, comrades! Today we have to get acquainted with the basics of building stairs. We will study the regulatory requirements for their device, find out the optimal dimensions of the march and a separate step. In addition, I will show and tell you how the outdoor stairs to the attic in my house are arranged.
Regulatory requirements
stairs
The rules for designing stairs in residential buildings are somehow affected in three documents:
- SNiP 2.08.01-89dedicated to the design of residential buildings;
- SNiP 21-01-97regulating the fire safety of buildings;
- GOST 9818. It describes the requirements for the manufacture of reinforced concrete marches for residential buildings, however, the requirements of the document for the dimensions of marches and steps will be useful in our case as well.
For the convenience of the reader, I will summarize all the requirements that are relevant to us in a general list.
- Number of steps in one march there should not be less than 3 and more than 18;
- Minimum march width in a private house is 900 mm;
- march slope should not be more than 1:1 (that is, the maximum angle of inclination is 45 degrees to the horizon);
- Minimum tread width (horizontal step platform) - 25 centimeters;
- Max step height - 22 cm;
- Landing Width should be at least equal to the width of the marches. If a straight attic staircase is torn apart by a horizontal platform, the length of this march must be at least a meter;
The requirement for the length of the site is related to safety. A platform of sufficient size will allow you to stop if you fall and avoid serious injury.
- The walls to which the stairs adjoin must be smooth. Heating devices, lamps and other equipment can only be mounted in niches. Objects protruding beyond the plane of the wall are able to detain residents of the house in case of urgent evacuation.
A special case
There are a couple of additional requirements for wooden stairs. They are set out in SNiP II-25-80:
- Angle to the horizon should not be more than 40 degrees (slope 1: 1.25);
- For making stairs, dowels and other structural elements that are under heavy operational loads or are subject to heavy wear, hard hardwoods (oak, beech, ash) must be used. For other wooden structural elements, softwood is preferred;
Pine, spruce and fir treads not only wear out quickly. They still have dents from heels (primarily from ladies' stilettos). This breaks the protective layer of varnish, and the coating begins to peel off.
- Slant and knots banned. Wood moisture should not exceed 12%. Rocks that are not resistant to decay must be treated with an antiseptic.
fences
Requirements for fencing stairs in a private house are set out in SNiP 31-02-2001. Here is a short list of them:
- Railing design must be continuous (without breaks in horizontal sections);
- Fencing strength should allow it to withstand a continuous load of 30 kgf without deformation;
- Minimum railing height - 900 mm, and with a ladder height of more than 6 meters - 1 meter;
- Maximum distance between handrail posts (balusters) at the stairs above one and a half meters - 12 cm. The requirement is especially important if there are or are planning children in the house.
Ergonomics
Now - a few words about convenience.
The best option in terms of ergonomics is a straight march with a ratio of tread width and step height of 2: 1.At the same time, ideally, the width of the tread should not be less than the length of the foot in shoes (for a person above average height - about 30 cm).
With an optimal step width of 30 cm, the most convenient riser height is 150 mm.
A spiral staircase (internal and external) allows you to significantly save space. But it is extremely inconvenient when transporting large items (furniture, drywall, plywood, etc.). When finishing the attic, I had to lift all the bulky building materials on ropes through the balcony railing.
The minimum width of a spiral staircase is one meter, the optimal one is 1.2 meters. It should be wider than a straight line because the part of the step near the support column has a too narrow tread that does not allow you to put your foot on it. This feature, with a width of 90 cm or less, will not allow two residents of the house moving in opposite directions to disperse.
The width of the wedge-shaped winder steps at the turn between flights must be at least 10 cm in the narrow part and 26 cm in the middle of the flight.
To increase the slope, while maintaining the relative ease of use, allows the "duck step" ladder. The steps of the stairs are not symmetrical: half of the tread has a large width, which allows you to comfortably place your foot, and the second half is smaller so as not to interfere with carrying the other foot to the next step.
materials
With wooden stairs, everything is clear: recommendations for choosing wood are unambiguously set out by SNiP II-25-80.And what is better to build outdoor stairs?
Staircase to the attic, combining low cost and maximum durability, is a steel frame with reinforced concrete steps. The reinforcement is placed in a frame welded from a corner, a formwork is tied up from below (a sheet of laminated plywood cut to the size of the step), and the step is poured with concrete. Tiles are usually laid on top of the set concrete.
Use tiles with a rough surface as a step cover. Glossy tiles in the rain and snow will become slippery.
Alternative solutions for street stairs:
- Plywood impregnated with drying oil. Impregnation is carried out twice without intermediate drying. Drying oil must first be heated in a water bath: then it will penetrate deeper into the wood structure;
- bakelite plywood. Thanks to gluing with Bakelite varnish, it is absolutely resistant to moisture.
Bakelite plywood is a rarity in hardware stores. In addition, the high price deters it: a sheet 21 mm thick will cost 5,000 or more rubles. An intermediate solution is treads made of laminated plywood with impregnation of the ends with drying oil.
My experience
In my house, the attic floor was built on top of the slab floor instead of the cold attic. In order to avoid problems with strengthening the slabs around the opening, it was decided to make the stairs external; the limited space of the forecourt dictated the screw design. Here is the appearance and description of the main nodes of the stairs.
| Image | Knot |
 | Base: reinforced foundation about half a meter deep.The central pillar of the stairs is installed on the foundation with a platform welded to it from a sheet 5 mm thick, reinforced with four scarves, and fixed with anchors. |
 | support post: 108mm thick steel pipe. To protect against corrosion, it is painted with PF-115 alkyd paint over GF-021 primer. |
 | step frame: assembled from a corner 25x25 mm. Rigidity is provided by vertical connections between the edges of the steps and a bevel of smooth reinforcement with a diameter of 14 mm. |
 | tread: made of 12 mm thick FK plywood, painted with rubber waterproofing paint. To avoid slipping, corrugated aluminum sills are installed on the edges of the treads. |
This version of the stairs is good, first of all, for its cheapness: at the time of construction (2013), it cost me 26,000 rubles. Rubber paint provides high-quality waterproofing; however, in the sun, the top layer of plywood still showed a few cracks, and the steps are in need of minor repairs. Otherwise, the design proved to be strong, reliable and (as far as can be judged by the results of 4 years of operation) durable.
Conclusion
I hope that my recommendations and experience will help the reader in construction. To learn more about how and from what a staircase to the attic can be built with your own hands, the video in this article will help you. I look forward to your additions and comments to it. Good luck, comrades!
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