- Balcony – design features
- How to restore the strength of a balcony slab
- Balcony glazing options
- Nuances arising in the process of glazing and insulation of balconies
In this Article: Building a Balcony what affects the deterioration of the balcony; how to increase the strength of the balcony base; balcony glazing – goals and options; some of the nuances accompanying the work on insulation and glazing.
Own living space in a multi-storey building has one common drawback – it is always small, especially with sufficiently high-quality glazing and insulation. In order to increase the living space, the apartment owners go to various tricks – they demolish the internal partitions, reducing the area of the bathroom and kitchen, unauthorizedly attach to the apartment an utility room on the stairs, previously used for a garbage chute, etc. Among the many legal and illegal options for expanding the living space of apartments, the simplest, and most importantly, legal, is the glazing of the balconies. Let’s explore this way to acquire additional footage.
Balcony – design features
This subspecies of the terrace is arranged simply – a platform is fixed on the beams protruding from the wall, bounded on three sides by a railing, and its reverse side is close to the wall of the house. By the way, for many balconies and other types of terraces – loggias – are synonymous, but this is not true, since the loggia is fenced off by at least three walls and has only one wall with a gap, fenced with railings or closed by a window sash.
Like the loggias, the balconies in the design of buildings were not designed for any kind of insulation, and the openness of their site was compensated by the slope of the slab forming the floor outward, in order to drain seasonal precipitation.
Balconies in houses erected more than 70 years ago were created from stone or reinforced concrete slabs, laid on steel beams fixed in the facade walls. In houses, called for some time “Khrushchev”, the precast concrete slab of the balcony platform was embedded in the wall. The platforms for balconies in modern buildings are standard reinforced concrete slabs rigidly fixed in the facade walls.
A typical balcony perimeter fence is made of a steel bar with a round or square cross-section; a wooden beam with rounded ends is used as a handrail. Such a fence should have a height of 90 to 110 cm, the distance between steel rods should not exceed 10-12 cm. Asbestos-cement slabs are used as wind screens in typical residential construction. Galvanized steel drain gutters are mounted along three sides of the balcony slab, protruding 15 cm beyond its perimeter.
Before considering the insulation and glazing of loggias or balconies, it is necessary to find out the condition of the base plate, the wear of which increases significantly under the following factors:
- Contrary to the conditions of the project, the floor slab was installed with a slope towards the wall of the building during construction, which led to the accumulation of moisture. The result of this can be multiple cracks in the concrete slab – when moisture penetrates into microcracks and freeze-thaw cycles, the cracks expanded, weakening the slab structure;
- deterioration, partial or complete absence of gutters for draining precipitation, which should be present on the underside of the balcony slab;
- the absence of vertical wind screens around the perimeter of the balcony fence, partially covering the slab from the penetration of atmospheric precipitation. It should be noted that such screens do not provide complete protection against moisture – slanting rains and strong winter snowstorms will still deliver moisture to the surface of the balcony slab, in this case it must be periodically cleaned of wet sediments.
How to restore the strength of a balcony slab
Multiple cracks in the mass of the slab forming the floor signal hidden defects, therefore, it is impossible to perform any insulation of balconies without preliminary strengthening of the slab structure. The reason for the obligatory strengthening of the slab is as follows – the fencing and glazing of the balcony perimeter will cause an increase in the loads on the slab, and in the presence of cracks, especially those directed perpendicularly, the slab design may not withstand. Consider ways to strengthen the balcony slab – a screed and additional reinforcing mesh.
Cement strainer.The use of this method is permissible only in case of minor damage to the balcony slab, namely, the presence of small and shallow cracks, insignificant surface drops. During the work, the surface of the slab is thoroughly cleaned of dirt, then leveled with cement mortar with the formation of a slope of 1.5 ° to its outer side. After the formation of a new outer layer of the slab, its surface ironing is carried out with dry cement – the freshly laid screed is sprinkled with a layer of cement, leveled with a trowel. Curing of the screed will take from 2 to 4 days, depending on the time of year, during the entire period, while the screed is gaining strength, it is absolutely impossible to walk on its surface.
Installation of a new reinforcement mesh.It is carried out in case of serious structural damage to the balcony slab, significantly weakening its bearing functions. The reinforcement mesh is created from steel wire 5 mm thick, the rods of which are welded or tied with a knitting wire so that for each running meter of the balcony slab along its length, there are at least 3 steel rods both along and across. The assembly of the reinforcing mesh should be carried out outside the balcony, before laying it, the surface of the balcony slab is completely cleaned of any contamination. Then the reinforcing mesh is laid on the slab, a gap of 2-3 mm is set between them, which is necessary for the penetration of liquid concrete under the steel rods – concreting is carried out so that the thickness of the concrete layer is twice the diameter of the reinforcement. The surface layer of concrete laid on top of the steel reinforcement can also be cured with dry cement.
Deep damage to the balcony slab, in which its strength weakens so much that it is simply scary to use the balcony, it is not recommended to try to fix it on your own – it would be wiser to contact specialists who have sufficient experience in this matter.
Balcony glazing options
Depending on the purposes of using the balcony, after its isolation from the external environment, glazing methods are selected from simple to complex. Consider two glazing options.
Dry and spacious pantry.By turning the balcony into a storage room, you get a room protected from atmospheric moisture in which you can store things that are not exposed to low temperatures. In this case, glazing is carried out using frames made of an aluminum one- or two-chamber profile, from a plastic profile of the “balcony series”, double-glazed windows can consist of one or two glasses. In this case, the covering of the balcony fence is performed with clapboard or, for example, moisture-resistant plasterboard. The result will be a room isolated from street dust and noise, but in winter the air temperature in it will be only 3-4 degrees higher than outside, i.e. it will be impossible to store a stock of vegetables and canned products in glass containers in it – it is too cold. For greater thermal insulation from the external environment, you will need to insulate the walls, floor and ceiling with polystyrene or mineral wool, after sealing all the cracks. Yes, you will need to install window frames from a three-chamber PVC profile, preferably a “standard” series. What is the difference between “balcony” and “standard” series of PVC profiles, you will learn from this article.
Full room.Since the balcony in its original design was not designed to be converted into a room, there is a lot of work to be done – finishing the loggias is much easier. The outer walls of the balcony railing must be made only of light structural elements, since the balcony slab is not designed for massive walls. The best option for wall fences on the balcony is foam block masonry, the air pores inside which will serve for greater thermal insulation of the room (however, you will need to close the masonry outside with a layer of plaster or a “ventilated facade”). The interior decoration of the future room is carried out according to the standard scheme – a layer of insulation, vapor barrier and decorative decoration with plastic panels, clapboard, etc. Glazing of the balcony with such insulation is carried out with frames made of a three-chamber plastic profile not lower than the “standard” series, with double glazing. As an option – frameless glazing, using tempered glass with a thermo-reflective film glued to its surface. Frameless “French” windows will look especially great!
Since any attempt to solve the problem of heating on an insulated balcony with the help of water radiators connected to the central heating system will immediately oppose the heating system, it will be necessary to use electric heaters – the best option would be an electric convector or “warm floors”.
Nuances arising in the process of glazing and insulation of balconies
In addition to the issues of choosing professional performers and agreeing with them the budget for converting a balcony into a closed space, the following points must be taken into account:
- wind load.Starting from the 9th floor and above, the glazing area of the balcony is under constant wind load. With a weak fastening of glass units in the frame and under the influence of winds, the glass will vibrate and loosen until it falls out of the frame. It is necessary to take into account the wind load at the glazing design stage, informing its structure of the required shape and rigidity;
- fire hatch and gas pipe.The balconies of the top floors in some high-rise buildings are equipped with hatches leading to the roof, and gas pipes are often laid at the ground floor level and run along the wall of the building at the ceiling of the balconies. Hatches and gas pipes cannot be categorically covered with cladding during insulation, otherwise problems with the fire and gas service are guaranteed;
- expansion of the balcony slab (take-out).The advantages of this operation, expressed in increasing the balcony area, are understated by possible problems – violation of the “architectural appearance of the building”, which is fraught with conflict with government agencies and weakening of the load-bearing characteristics of the slab, which is bad in itself. If you have already decided to increase the width of the balcony slab by 400 mm (no more!) With the help of a system of brackets, then first obtain permission from the architectural supervision and make sure of the real professionalism of the performers – if they make a mistake, the consequences can be quite tragic.