Grouting in brickwork is an element of the facade decor. In addition, high-quality joining prevents the deterioration of the thermal conductivity of the wall and prevents moisture from entering the seam, which can destroy the masonry at subzero outside temperatures..
Each type of jointing involves its own tool, which is called jointing. You can buy a ready-made tool in the store, but bricklayers often use homemade jointing.
This joint can be used for both concave and convex seam treatments. You can make such a tool yourself from a strip of metal..
Prefabricated tool for concave jointing.
Factory jointing for a convex seam.
Flat jointing is used for single-shear, double-shear, as well as straight buried types of joint cutting. A double-cut concave seam is obtained using the pointed end of such a jointing.
Some masons use a rubber hose for concave joining, with a diameter approximately equal to or slightly greater than the thickness of the joint.
In some cases, a trowel handle is used to make concave jointing..
The mortar for brickwork plays an important role, directly affecting the strength of the structure. The binder, which is part of its composition, subdivides solutions into cement, lime and mixed (cement-lime, cement-clay). The cement-sand mortar is superior to the others in terms of strength and resistance to environmental influences. The disadvantage is the higher price and lower ductility, which is very important for masonry with jointing.
The plastic properties of the cement mortar can be increased with the help of natural plasticizers (lime, clay) and artificial plasticizing additives (surfactants). The latter also have moisture-holding properties..
The building materials market offers plasticizing additives of domestic and foreign manufacturers. Some of their types not only increase plasticity, but also retain the strength characteristics of the solution, and some even increase them. Superplasticizers are increasingly used today. These are high molecular weight surfactants.
The selection of the grade of the solution and the necessary additives depends on the temperature and humidity conditions of the outside air and internal premises, the purpose of the building or structure, the height of the brickwork, as well as on the required strength and durability indicators of the structure itself.
Important! For an independent choice of the ingredients of the solution, it is necessary to take into account that sand with admixtures of clay, mica, dust particles significantly reduces the strength and frost resistance of the solution.
For low-rise construction, the grade of the solution is used at least 25, and for wet rooms at least 50. For example, the composition of the cement-sand mortar grade 50 with the addition of lime as a plasticizer:
- cement M300 – 1 part;
- lime – 0.7 parts;
- sand – 6 parts.
Today, along with the old cement marking, there is a new one. This must be taken into account when purchasing cement. М300 (old marking) corresponds to CEM 22.5 (new); M400 – CEM 32.5.
The choice of the type of jointing depends only on the desire to obtain a decorative effect from the seam.
Direct recessed jointing
This jointing is done with a flat jointing trowel. Sometimes a simple metal strip is used with a width equal to the width of the seam. This type of jointing creates the effect of overhanging the brick and visually lightens the massiveness of the structure..
Here the seam is not buried in the masonry structure. The mortar, which is squeezed out when the brick is pressed against the mortar bed, is simply cut by the mason with a trowel, flush with the brick. To eliminate irregularities and obtain a smooth surface, the seam can be passed along it without pressing with a flat jointing.
This type of jointing is most often used in masonry work. Creating a beautiful texture of the wall surface, such a seam treatment seals the mortar well and reliably protects the structure from moisture. Some bricklayers make such jointing from a piece of metal pipe, a rubber hose, a trowel handle, and even using a simple wire bent in half, rounding the fold along the diameter of the seam. However, there is no sealing of the seam here..
This type of jointing is much less common in brickwork. For a homemade utility tool, a metal corner with dimensions corresponding to the thickness of the seam is suitable. Aesthetically, this jointing creates an additional line in the middle of the seam, which has a certain decorative effect.
Quite a common type of joining. Here, the seam is allowed to go beyond the masonry surface no more than 3 mm. However, it is desirable that the seam does not protrude relative to the outer surface of the brick, since the strength of the mortar is lower than the strength of the brick. The protruding part of the mortar increases the possibility of external damage to the seam.
Such jointing, as well as double-cut, is used quite rarely. Produced using flat jointing or a sharp trowel, cutting off part of the mortar at an angle to a depth of 3-4 mm. It must be done exactly as shown in the figure. Otherwise, in the place where the seam is buried, there will be a possibility of accumulation of water and dirt, which will shorten the life of the masonry itself..
Sequence of brickwork with jointing
Compliance with strict horizontal and vertical seams of brickwork affects the strength of the entire structure. In this case, the load on the foundation is transmitted evenly, which ensures the stability of the entire structure..
Brickwork with seam treatment consists of the following sequential operations:
- The ordering is being installed and the mooring is being pulled.
- The brick is laid out on the wall at the place of work.
- The mortar bed is laid under the outer verst.
- Outside masonry is being laid with simultaneous trimming of excess mortar.
- The solution is spread under the inner verst.
- The inner verst is being laid.
- The solution is laid out for forgetting.
- The masonry is being forgotten.
- The correctness of brick laying is checked.
- The seam is sewn.
The jointing sequence must be followed. Horizontal seams are cut only after vertical ones. The horizontal joint should be 12 mm thick and the vertical joint 10 mm thick. In special cases stipulated by the project, you can change the dimensions of the seam, but in the range from 8 to 15 mm.
The simultaneous amount of work on the processing of seams is limited by the setting time of the solution. The mortar, which has lost its plasticity, does not make it possible to seal the seam, crumbles, which leads to a significant deterioration in the quality of the masonry.
Important! If it rains unexpectedly during masonry, the fresh masonry must be protected from moisture. You can cover it with some kind of waterproofing material, otherwise the fresh mortar in the joints can wash out.
Beauty is often in the little things. By choosing one or another type of jointing, you can achieve a variety of textures for building facades.