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4. Why it is impossible to deviate from the design on the example of facade work. The right approach to preparing for facade work.
ОглавлениеWhen a customer decides to update the facade of his building, he usually asks: “How much will it cost to mount the facade?”. Whatever the question is formulated …, such is the answer. In this review, we will figure out what questions, how and to whom to ask in order to get the right answer.
The solution of the facade issue is a series of stages that mutually influence each other, and at some point it may be necessary to revise the original plan completely.
1. Preliminary concept
First, the desired appearance and, accordingly, the materials used are determined. It is important to understand that in addition to the main cladding of the building, you will have to plan the cost of installing window slopes and ebbs. Also, the cost of installing a new parapet will come out if the roof is flat, and if you have small cornice overhangs, then they may have to be increased.
Of course, you can hire a designer to draw everything approximately or exactly for you. At this stage, no one can tell you the exact cost of the work, but only the order of numbers. Alas, this is just the beginning.
2. Coordination of the facade and its changes by the state executive authorities
For example, in Krasnoyarsk there is a procedure approved by the city administration for approving the passport of the facades of buildings and structures, with the exception of individual housing construction. Therefore, your lawyer should check the existence of such requirements for your object.
In Krasnoyarsk, as part of the documents, it is necessary to provide information on the color scheme, on the materials used, lists and layouts of additional equipment, elements and devices, architectural lighting scheme, etc.
This means that it is easier to make a project than not to do it. But in fact, the project needs to be done. Now check it out.
3. Design
3.1. Design surveys, encumbrances
When constructing the facade, we increase the overall dimensions of the building. This value can be different, from 100 mm to 700 in my memory. In addition, often in the process of facade reconstruction, the owners decide to additionally arrange canopies over the entrances to the building or even porches – accordingly, this is an indent from the building up to 2 meters. Behind the facade, the blind area can also shift.
Therefore, at the design stage, it is necessary to check whether, after the reconstruction of the facade, the violation of the red lines, the boundaries of easements and the security zones of engineering networks will not occur – otherwise, you will have to dismantle everything that you mount in such areas.
3.2. Purpose, fire safety class of the building, height of the building
The parameters indicated in the title of the paragraph affect the requirements for the materials used, the arrangement of individual components of the facade structure, and further on the cost of work and materials. As a rule, most facing materials (granite, plaster, metal and composite panels) meet such requirements, but all kinds of PVC do not. The same with insulation, mineral wool – does not burn, polystyrene foam – is limited in use. In addition, heaters have restrictions on the height of the lined structures. In general, there are enough subtleties.
3.3. Inspection of the condition of walls and suspended structures
There is no point in explaining this. It is clear that all worn-out sections of the structures will need to be restored, which is not firmly fixed – it is necessary to remount. A project for such work is necessary by definition.
3.4. Fastener testing
During the examination of the walls, the type of facade anchors and insulation fasteners used is determined. It is not always possible to use conventional anchors, and chemical ones may be required. But the choice of fasteners is made not only by calculation methods, but is confirmed by acts of laboratory tests for pull-out directly at the object. Typically, pull-out tests cost about 5 – 10 thousand rubles. plus a round-trip if the facility is a long distance away, but manufacturers can do these tests at their own expense if you express interest in continuing to purchase and use the tested fasteners from them.
3.5. Thermal calculations and choice of insulation
This is generally a very important question, because. the cost of heaters ranges from 2000 to 9000 rubles / m3 , and possibly even higher. Expanded polystyrene heaters – provide better thermal insulation, but have limitations on use, because. are not non-combustible, unlike mineral wool . A combination of less dense (“cheap”) and denser (“expensive”) insulation materials is allowed to achieve optimal thermal insulation of the walls.
Often, customers have no idea about such subtleties and make a decision “by eye” and at a price – which is fundamentally wrong.
3.6. blind area
Depending on the chosen type of facade, its installation begins either directly from the blind area, or with an indent from it by 20 mm – if a ventilated gap is needed. Therefore, before performing facade work, it must already be completed.
But there is a certain problem with the blind area – this is the state of the soil and its seasonal swelling. The condition of the soil can spoil both a single flooding of the site, and a change in the state of groundwater, showers, etc. In this case, improper performance of work on the blind area may lead to its rise.
From practice, the lifting height can be both 50 and 100 mm. Accordingly, the pressure from the blind area passes to the facade elements, crushing them like an "accordion", shifting the facade subsystem along with the cladding. As a rule, a gap is made between the profiles for thermal expansion of the metal, but it is only about 10 mm. Considering everything, in the best case, only the facade of the first floor, or its lowest part, may suffer, in the worst case, the deformation of the facade will go higher.
Therefore, the development of a project and a survey of the state of the soil in terms of the blind area during the construction of the facade are mandatory.
3.7. seismicity
The choice of facade materials, fasteners, etc. the seismicity of the area in which the object is located. Therefore, in areas with high seismic hazard, the materials used must be certified for use in such conditions, and in the event of earthquakes, they must minimize the risk of injury during failure. This also makes adjustments to the final appearance of the facade, its technology and cost.
3.8. Gaps between metal elements of the facade
Often, customers want the joints between the individual panels of the facades not to be visible and ask to make the installation without gaps. Alas, due to the thermal expansion of metals, facing materials can become unusable, deformed. Even designers forget about it, but you must remember and demand compliance with these standards.
3.9. The layout project of the profile system, cladding and individual components of the facade
Only at this design stage it is possible to see the future appearance of the facade as close to reality as possible, to see the visualization, to understand the cost of work and the need for materials.
But, now we have to wait for the decision of the supervisory authorities … And only then either correct the project, or finally start the work in accordance with the current regulations.