Table of Contents
In the majority of owner-occupied dwellings and separate economic buildings the cellar is used as cellar for storage of products, workshop or the storeroom for storage of things, tools and different stock.
For normal operation of the basement it is necessary to equip convenient descent, i.e. to make the ladder answering to all standards of safety. The facilitated model, certainly, can provide rise and descent, but without security guarantee and comfort of its use. That the basement was full-function, it is necessary to provide it to the reliable national team (from ready purchased elements) or concrete ladder. Construction of such design will not make big work if to know the basic principles of its creation, to have necessary tools, devices and to have skills of economic construction jobs.
To what norms it is necessary to adhere at ladder construction to the cellar?
According to the existing norms:
- Width of stair flights has to be identical on all length of design, irrespective of the number of marches; for cellars in residential buildings it is more convenient to use door and ladder 90-100 cm wide. If it is supposed to make rotary model, then width should be chosen not less than 1 meter. This size will provide simultaneous movement of two people and possibility of movement on ladder of dimensional objects.
- Stair landings and marches adjoining it have to be identical width.
- In length stair landing has to be about 140 cm, i.e. make length of two steps of the adult.
- The outer door (sliding or opening not towards the cellar) length of stair landing has to have not less than 1 meter. If the door opens towards the cellar, then the size of site is chosen, proceeding from the sizes of door cloth and reasons of safety of the person who is at door.
- In 1 march there can be not less than three and no more than eighteen steps, it is recommended to provide odd quantity of steps as intuitively the person assumes to finish the movement on steps with the same leg with which it began to go down or climb it.
- The recommended bias makes 260, limit: on the upper bound of the steepness 500, on lower – 200.
- The curvature of bisecting line of march on design with wedge-shaped steps has to exceed the radius of 30 cm.
- Steps within one march have to be identical and differ from each other in the sizes no more than on 5 mm, height and depth of tread of subsidiary ladder has to be 200 mm.
- For wedge-shaped steps the tread cannot be less than 100 mm, on bisecting line of march this size should not be less than 260 mm.
- Handrail has to have height not less than 900 mm, between racks it is necessary to maintain distance no more than 150 mm.
- Barriers have to be expected lateral load of 100 kg, it will provide reliable support of the adult on them.
- In the basement it is necessary to provide lighting that the ladder was well visible, especially its first and last steps. Switches have to be located in convenient access at once at cellar entrance.
- At design it is necessary to consider height between upper site of ladder and overlapping.
- Material for production of ladder to the cellar has to be strong and correctly processed.
Choice of design and materials
When choosing model of ladder to the cellar it is necessary to be guided on:
- possibilities of own budget;
- readiness of investment in construction of own physical forces;
- possibility of holding these or those actions concerning construction;
- expected operational loadings;
- compliance of model to the general space registration, the sizes and structure of the connected rooms;
- convenience of further use of construction.
It is also necessary to consider how capital has to be ladder and to what adverse factors it can be exposed in the course of use. Prior to construction it is necessary to make calculations and the sketch of design, in view of, first of all the fact that future ladder has to be convenient, completely safe and not encumber the cellar.
For arrangement of the cellar it is possible to make ladder of one of the main types:
- one-mid-flight rectilinear;
- one-mid-flight with intermediate site in the form of the letter “Z”;
- two-mid-flight with parallel or perpendicular marches with intermediate site;
- two-mid-flight with wedge-shaped or semicircular steps;
- screw, fixed on wall or the central pipe.
The one-mid-flight straight staircase will be the simplest design, of course, but not in each space it is possible to establish such model. When choosing tilt angle of design, it is necessary to adhere to normative recommendations and not to exceed admissible corner, but also too flat ladder will take a lot of place, the low subladder space cannot be used further. Therefore at design it is necessary to try to consider all nuances of the basement.
Choosing material for production of basement stairs, it is necessary to consider that in not heated basement the humidity is always increased and if to choose tree, then it needs to be strengthened effectively by means of antiseptic impregnation and moisture protecting cover. But even these actions will not be able to provide so long term of operation of ladder to the cellar, as well as other wood structures in the house. Standard steel concrete ladders of massive and their production it is accompanied by certain difficulties. Standard concrete structures not always approach under the sizes and bearing capacities of the existing basement. The all-cast model under the sizes of the cellar can be made most, having applied metal corner or thick rods as armature. But the construction of timbering will require many wooden boards therefore lack of this design is its high cost and labor input of process.
If desired to make basement stairs by own forces, the most rational option is the design consisting of metal profile beams: metal channel 8-12 mm thick or I-beams, pipes of circular or rectangular cross section trimmed with tree or metal. The processed metal will serve long, and wooden parts, if necessary, it is possible to replace. As a rule, steps make of metal sheet not less than 4 mm thick or wooden boards 40-50 mm thick.
It is not obligatory to do metal framework welded, it is the most reasonable to choose model on bolted connections. It will allow to do without welding and to collect framework by means of set of wrenches, the perforator and saw.
Structural components of ladder
The traditional design of ladder consists of platforms and marches. Marches consist of the steps fixed on the bearing longitudinal elements. There are two types of mounting of steps to longitudinal structural components:
- Steps are fixed by means of nails or bolted connections by the side edges to beams.
- Steps keep within on the bars which are previously fixed to beams from above.
The sizes of step have to be convenient for human leg therefore they choose height of step of 40-45 cm depth of tread of 25-28 cm. When choosing timber frame construction, bars for vertical elements take section 80х100 or 70х150 of mm. It is admissible to apply wooden bars and other sections provided that they will provide lack of deflection at simultaneous stay on ladder of 3 people.
Screw models are most compact that is relevant for small cellars where economy of space is required. For their production the central support from metal pipe or wooden bar with a section not less than 150х150 mm is used. But if the ladder is intended for the economic cellar, then screw model not absolutely suitable option because with dimensional objects of it it will be inconvenient to move, to especially elderly people. The screw design will quite satisfy need of the room equipped for the gym, billiard room or the restroom. In addition to practical function, in this case, the screw model will carry out also role of interior element.
If there is need for compact ladder for cellar, then it is necessary to consider option of broken design with one or two platforms. In form such ladder will remind screw, but not round, and changing the direction at an angle of 90 or 180 degrees after platforms. If to provide width of 90-100 cm and not too abrupt tilt angle, then such ladder will be convenient for frequent use and movement on it dimensional objects as the person will move on it on straight line, doing turns only on horizontal platforms. Platforms, besides, can serve as intermediate stop, at difficulty of movement on them it is possible to have a rest, having put load on floor.
Production of metal ladder
To calculate necessary quantity of steps and length of vertical elements, it is necessary to be guided by basement height from floor before overlapping of 1 floor. For example, if height is 300 cm, then in view of the requirement for the size of steps (20 cm), them there have to be about 15 pieces. It is possible to make one-mid-flight ladder or two-mid-flight with one site with quantity of steps 9 and 7 or in other ratio.
When carrying out calculations it is necessary to consider also height of future half of the cellar.
Construction of ladder is begun with construction of supporting structure. If the ladder adjoins cellar wall, then it is necessary to begin with fastening of side vents to wall, on slits armature will be established. The wall will bear heavy load therefore it has to have sufficient characteristics and have margin of safety.
If the ladder does not have side wall support, then build the lower and upper support.
At width of stair more than 1 meter of step needs to be strengthened in addition.
Ate steps will be from concrete, solution should be done dense and it is obligatory to take small break 2-3 minutes between arrangement of steps. The adjacent wall laying and timbering before laying of solution needs to be moistened with water, it is more convenient to do it by the sprayer. You should not level the condensed concrete carefully, finishing alignment to be made when laying covering or after full hardening of steps.
In the presence of 5 and more steps it is necessary to provide hand-rail. Handrail has to be carefully polished not to injure hand during descent or rise on ladder. Standard height of handrail of 90 cm that corresponds to growth of the adult.
In subladder space, especially in case of design adjunction to wall, most often equip racks for storage of different objects. Component parts of rack have to be calculated considerable mechanical loading if on shelves heavy objects will be placed. For not heated cellar it is necessary to use the materials steady against humid environment for production of rack.
To what nuances it is worth paying attention:
- Whenever possible, assembly and processing of designs need to be made out of the cellar, especially painting works as in the closed space during the work with paints there is risk of poisoning.
- It is necessary to consider that works should be performed in the constrained conditions.
- Taking some ready project as basis, it is necessary to correct it and to bring into accord with own sizes of the cellar.
- Before performance of work it is necessary to be defined where construction materials will be stored: if in the cellar, they can impede performance of work if in the economic shed, their movement can occupy considerable part of time.
- Constructing ladder, it is necessary to consider that at movement on it there is not only risk of falling, but also risk of heading about overlapping.
- If under floor communications are laid, then they reduce the useful height of basement storey.