Plastering . Also called plasters , they are thin, smooth and generally impermeable layers of construction materials , used to cover walls or walls, beams , columns , etc.
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- 1 Functions
- 2 types of repel
- 3 Most used dosages
- 4 Description of dosages
- 5 Repel thicknesses
- 6 Resanos
- 7 Fine repello
- 8 Thick repel
- 9 Rustic repello
- 1 Types
- 2 Uses
- 10 Bitumen
- 11 Putty Plasters
- 12 Stucco
- 13 Plasters
- 1 Uses
- 14 Veneers
- 1 Natural stone veneers
- 2 Artificial stone veneers
- 3 Tile veneers
- 4 Ceramic veneers
- 15 Sources
They can fulfill very diverse functions, although the main ones are the protection of the structures of the buildings of the atmospheric agents (extending their useful life), stiffening them making them more resistant and the ornamental.
Types of repels
The repels or plasters can be grouped into the following:
Most used dosages
The repels can be made using different combinations of materials, the usual ones are:
- Cementand sand
- Cement and third
- Cement, receboand sand
- Cement, lime hydrate, recebo and sand.
This list includes the four most common combinations, and any other variations that are made will always revolve around these materials, with the possibility of adding some other material such as mica or coloring , but will not affect the quality but only the aesthetic appearance. Each of these types of mortar is used according to the special circumstances of each work and we can summarize them as follows:
- From the functional point of view of the construction elements or parts of the works to be coated.
- According to the finish or texture that you want to give the wallsfor its architectural design.
- According to the budgetary economic conditions of the work.
- According to the existence of materials that exist in the area.
Description of dosages
- Hydraulic mortarof 1 part of cement by 3 parts of sand (1: 3)
From the functional point of view, we can generalize for all the works that, before starting to repel, it must be cleaned, minced, wetted and coated with a thin layer of this mortar, all concrete surfaces , whether columns , footings , enclosures , eaves , among others, because of not taking this precaution, any other mortar that we apply in the general repello, will tend to detach from concrete surfaces that have not previously received this treatment. This mortar is also used in places that will be in contact with the water after being repelled and in the final layer of the rustic repello.
- Cement and third aerial mortar. Usual dosages
- For interiors, 1 part of cement per 10 of a third (1:10).
- For exteriors, 1 part of cement by 8 of a third (1: 8).
These mortars are used in the construction of thick resals and repulses, as well as the fine ones with a greater percentage of cement and sifted by a sieve of the so-called mosquito net.
- Cement, recebo and sand aerial mortar. Usual dosage for both indoor and outdoor.
- One part cement, 3 parts recebo and 5 parts sand.
These mortars can be used for the same repels as those of cement and third. Whenever its use is possible, both for economic reasons, and for its availability in the region, it is advisable to use the mortar based on a third, instead of mortar based on recebo, because the latter material has a tendency to crack with its consequent failure to protect the walls, in addition to how ugly that defect is. This does not always happen, because it depends on the quality of the recebo, its proportion in the mortar, and its way of placement.
With the third mortar, the precaution to be taken is that the lime with which the material is prepared, is well turned off to avoid caliches, which consist of grains of lime that have not been perfectly hydrated and in doing so explode and leave a series of recess holes, very bad looking.
In most cases, the mortar based on a third costs more expensive than the receipt and the price varies depending on the area. There are also regions where it is difficult to obtain lime and others where this material does not exist.
Among the advantages we have when using the third is its resistance to changes in temperature, cracking, cracking and detachment, provided that it is properly placed in the repels; In addition, it is a more moisture-insulating material, as far as protection is concerned, it allows to obtain a very fine finish more easily than the recebo and also to achieve the fine directly in the first hand with much more ease and guarantee than the recebo. It is very easy to match, provided that the thickness of the repello is not greater due to the imperfections of the walls, in which case it is preferable to repel in two layers: the first, to match, and the second to obtain the fine that could not have been saved with the first hand.
- Aerial cement mortar, lime hydrate, recebo and sand . Usual dosages:
- One part of cement, 1 part of lime hydrate, 4 parts of 1 receboand 2 parts of sand (1: 1: 4: 2).
This proportion is variable according to the quality of the recebo and the sand, but the proportion of 6 volumes between the two does not vary, that is, in total.
This mortar is used for the application of bitumen or fines in interior and exterior repels, whose base or resona is also made of cement mortar, slab and sand. Depending on the color and texture that you want to obtain, gray or white cement, gray, red or black sand and stone or stone dust can be used.
It is very important to sift both the sand and the third and the recebo, although sometimes it is not necessary to sift the last two.
The non-sifted material is difficult to work for the coarse grains that, when trying to smooth the repellants of the walls, scratch the surfaces and prevent the correct functioning of both the rubbing and the trowel and even the same rule.
The thicknesses of the repels range between 1 and 1.5 cm. for resanos and replos with termination in a single layer; for bitumens or fines that are always applied on a base or resin, the thicknesses range between 1 or 2 mm.
All the reploses need a base called resano, which has the function of correcting the defects of the wall and producing an appropriate surface to receive the mortar layer of the paste or any other coating.
Applying the fine.
It is applied on the resin and constitutes a surface of fine grain, 2 mm or less thick; It is one of the most economical coatings that exist. The mortar used is of a finer grain than the resin and a certain amount of lime hydrate is added to give it greater plasticity, as described previously. With this a smooth surface is achieved by the smaller size of the grains of sand and using the rubber rub. It is used for both indoor and outdoor. You almost always apply paint to cover your pores and make it waterproof.
Although in the constructions the terms resan and thick repello are used in the same way, we consider it more successful to classify the thick repello as a finish, depending on the granulometry of the inert material or materials, as long as they constitute a flat surface. In very economical constructions, it is applied as a single layer, that is, following the rules of the resonant construction process, although the rubbing is done with more care and painted later. This does not exclude the use of a thick repello on a base layer of resin and consider it as a repello more in two layers.
It is one whose surface is not flat, but has a certain relief, the product of its construction and the effect that is to be achieved. It is applied on a resin, not directly on it, but through the use of a metallic fabric or mesh, passing it through it.
The types of rustic repels will be given according to the type of mesh used in its construction, that is to say that according to the size of the gaps of the mesh will be the texture that is obtained.
Rustic repels are used for aesthetic purposes, usually on facades, as they form a rough surface not suitable for interiors.
It is a special type of fine repello, which does not need paint and imitates limestone when it has been awakened (scratched that simulates stonework), or simply maintains the appearance of a repello more. Special mortars are used for bitumen repellent, which are more resistant and durable, based on sand, gray or white cement, lime hydrate, stone dust (of ordinary limestone or some special type) and sometimes mica particles. It is applied on a base or resona and is executed with the greatest possible care in terms of mortar dosing and rubbing. In constructions, the term bitumen is sometimes applied to any fine repello finish, but we must clarify that, although the word is not quite correct, bitumen is that type of repello that does not need paint and has a mortar of special composition.
They are coatings composed of a paste of lime and plaster putty or lime and cement masilia. The surface is completely smooth, since they are applied on resonates or directly on concrete, through the use of metal liana or flat. The one of putty and plaster is an economic coating, of beautiful appearance, but with a big defect: the fragility; chipped, especially on the edges, occur with any accidental blow. Its construction is reduced to the application of the paste, which is extended by means of liana. On ceilings where there are indirect lights, a series of 6 master guides must be drawn that allow producing a surface as perfect as possible, that is, without undulations, to avoid that the light reflections highlight any defect. The finish between wall and ceiling can be at right or curved angle. Plaster of putty and plaster are used only indoors, since they are composed only of aerial adhesives that do not resist moisture. InCuba has used this type of plaster a lot, for its speed of execution, economy and beautiful appearance, but its use in walls has always been criticized, for the chipping that occurs at the slightest blow that the wall receives. It is also clarified that any repairs made are less visible than in the other repels. Plaster putty and cement have their greatest application where certain impermeability and polishing is desired, such as. In garage sockets, laundry rooms, dumps, cisterns, etc.
Main article: Stucco .
They are coatings of a smooth waterproof finish, of a certain hardness and shine that sometimes tries to imitate natural stones by means of color and veins made on purpose. They are always applied on a sand and cement resin, in several layers. The coating mortar is composed of plaster, marble dust and water (with dissolved glue); other times alum powder is added to give it more hardness. After applying this mortar and when it has already acquired a certain hardness, the veins or the desired design are painted and later it is applied to apply varnish and wax, to obtain a shiny surface. It is important to note that the composition materials and the process are a function of the quality of the crafts that are available and the work that is required.
There is another type of coating called plaster, where special plasters are used, with a more complex process. These plasters imitate marbles, their surface is hard and shiny and they were used with great profusion in interior details of houses (generally before 1930 ), such as baseboards, column shafts, and so on. For these works a skilled craft is necessary, since they require enough skill. It differs from the stucco in that the color is obtained by mixing dye with the paste.
They are applied in places where a non-porous polished surface is necessary, such as wall and stair baseboards, etc. They are cheaper than natural stone veneers. The plaster is disused in Cuba because of the large amount of labor required.
Ceramics for veneers.
They are made of natural or artificial materials, and are applied in the form of sheets or plates , slabs , pads or prefabricated elements . They are applied with mortars , melts, special glues, metal staples, screws , nails , etc.
Natural stone veneers
The stones that are most used are granites, marbles and limestones. They are applied on plates that stick with cement melts. It is an expensive coating but of great beauty and durability. In Cuba, the coating with Jaimanite stones abounds. In the case of working with limestone, these are cut according to the need of the project, in the place of the work.
Veneers of artificial stones
It is done with precast mortar or concrete pieces; of ceramic materials such as ceramics, clay slabs, tiles and terracotta.
They are used in finishing bathrooms and kitchens for their cleanliness and impermeability. They are placed by using mortars and finally their joints are filled with a cement melt.
It is used outdoors for its durability and permanence, although it is an expensive procedure. For this veneer there are also special bricks and mud slabs, which are applied by mortar.
One of the materials used for this purpose is terracotta.