Ceresit CT 85 - plaster and adhesive mixture for expanded polystyrene: characteristics, consumption

The glue mixture Ceresit CT 85 is a composition for fixing expanded polystyrene plates and further forming a reinforced protective layer on them. In the latter case, we are talking about works in which there is a need to install a system of external thermal insulation of external walls using the technology of "wet method".

Main characteristics

Ceresit CT 85 has a lot of advantages, among which there is a high ability to adhere with expanded polystyrene and mineral bases, elasticity, vapor permeability, weather resistance, and environmental safety. The composition contains reinforcing fibers, the mixture is impact-resistant, frost-resistant and technologically. In order for the composition to show all its positive characteristics, sometimes there is a need to additionally prepare a surface that must be degreased and cleaned from foreign objects that prevent the insulation plates from stabilizing as smoothly as possible to obtain an ideal surface suitable for decorating the wall.

Scope of use

Ceresit CT 85 has a fairly wide range of applications, it is for this reason that consumers acquire this composition, refusing alternative solutions. This adhesive can be used to fix plates that are made of expanded polystyrene. Their fixation is very effective. The mixture is suitable for the production of reinforcing layers on such slabs, when the facade is formed by "wet" technology. This mixture can be used for insulation of new buildings or thermal protection of old buildings. When warming facades of buildings in a "wet" way with the use of mineral wool slabs , this glue is also used.

Specifications

Ceresit CT 85 is a mixture of mineral aggregates and cement, reinforcing microfibers and polymer modifiers. The density of the dry mixture varies within 1.3 kilograms per cubic decimeter. At 25 kilograms of the dry mixture, approximately 6.75 liters of water will be needed to make the solution. After preparation, the composition should be consumed within 120 minutes, while the temperature should be kept from +5 to +30 degrees. Operating temperature varies from -50 to +70 degrees.

Quite often, builders are interested in such characteristics as adhesion to expanded polystyrene. So, it is equal to 0.1 MPa. As for the adhesion to concrete, it is 0.6 MPa or more. Glue "Ceresite" is able to undergo about 75 cycles of freezing and thawing. If you plan to form a layer whose thickness will not exceed 8 millimeters, then in 28 days all cracks will be absent. It is very important to take into account also what Ceresit glue consumes. If necessary, fix the plates or form a protective layer, the flow rate will be 6 and 5 kilograms per square meter, respectively.

Preparation of the substrate before installation of expanded polystyrene plates

If you decide to use the composition of Ceresit CT 85, the characteristics of which have been described in detail above, then you should become more familiar with the technology of preparation of the base when installing the plates. The surface must be as strong as possible, free from dirt and foreign matter, which would be able to reduce adhesion of the adhesive to the substrate. This includes lubricants, paintwork, oil, grease and bitumen mastic. If there are fragile areas on the surface, then you need to get rid of them.

If there are depressions that are larger than 20 millimeters in size, the cavities should be filled with Ceresit CT 29, and this must be done three days before the beginning of the insulation work. Ceresit CT 85, the flow rate of which was mentioned above, should be applied to a surface completely cleaned of contaminants. To get rid of them it is possible a jet of water supplied under high pressure. Coping with such work can also be done with a solvent or mechanically.

If the fixing of polystyrene plates is carried out on plaster, oily or synthetic coatings, then the adhesive additive Ceresit CC 81, which is diluted with water in a ratio of 1: 3, should be used in the preparation of the dry mixture. Thus, one part of the additive will require 3 parts of the liquid. If there are paint coatings on the surface, they must be ground and dust-free.

Additional recommendations for training

The adhesive for expanded polystyrene Ceresit CT 85 is applied to a wall that is completely devoid of areas exposed to fungi, algae or moss. Such surfaces are brushed and treated with the fungicidal preparation CT 99.

Those walls that have not been plastered and used for some time should be de-dusted by rinsing with water under pressure. The walls are left to dry completely. Sometimes you have to work with strongly absorbent bases. This should include the surface of aerated concrete or silicate blocks. They are primed and dried for 4 hours.

Recommendations for the construction of a protective layer

Sometimes it happens that after fixing the slab ceilings remain in the open air for 2 weeks or more. Do not hurry to cover the adhesive protective layer of such grounds, to begin with they are examined. If the surface has changed color, dust appeared on it, then the insulation is treated with coarse sandpaper and dust-free.

Application of the formulation

The "Ceresite" glue must be prepared exactly according to the instructions. To do this, use cold water (its temperature should be in the range of +15 to +20 degrees). The mixture is added to the liquid and mixed, while obtaining a homogeneous mass. Stirring is effectively done with a mixer or drill with a nozzle. The speed of rotation of the working tool should not be more than 800 rpm. Then the master leaves the mixture for 5 minutes to "ripen", after it is stirred again.

Installation of plates from expanded polystyrene

As mentioned above, Ceresit glue is used for fixing expanded polystyrene boards. If the walls have irregularities from 3 to 15 millimeters, then the composition is applied by the trowel along the contour of the slab. In this case, the adhesive strip should be equal to 4 centimeters in width. In the central part of the heater are placed beacons. The number of such spots on one canvas should be equal to 8. Their diameter is 10 centimeters. The adhesive band along the contour should be applied with breaks, which will eliminate the formation of air bubbles. The height of such bands should be equal to 20 millimeters.

When the irregularities are up to 3 millimeters, the glue is applied with a continuous layer, with the indentation being three centimeters from the edge. In doing so, use a notched trowel. Choose a tool whose tooth size is 12 millimeters. As soon as the plaster-glue mixture was applied, the slab is applied to the surface and pressed with graters. The area of the adhesive contact after pressing the web should be 40 centimeters from the area of the bonded surfaces.

Plates are fixed in one plane in such a way that the dressing of the seams has a T-shape. It is important to ensure that the gap between the plates does not exceed 2 millimeters. Larger seams can be filled with polyurethane foams or cuts of expanded polystyrene. Clay "Ceresite" will dry completely after three days, only then you can proceed to additional fixation, if such a need exists. For this, the masters are advised to use facade dowels. After this period, the master can form a reinforced layer.

Formation of a protective layer

Begin these manipulations only after additional fastening of the heater with dowels. Their number per one square meter of the facade surface should be determined by calculations. The plaster-glutinous mixture is spread by a steel float over the surface, while the thickness of the layer can vary from 2 to 3 millimeters. On the glue layer is laid a grid of alkali-resistant glass fibers. It is important to ensure overlapping of the canvas from 5 to 10 centimeters in width. Immediately you can start applying a second layer of glue, the thickness of which should be 3 millimeters. The surface can be smoothly smoothened so that the grid can not be seen. On the protective layer after three days can be applied decorative coating of thin-layer plaster or alkali-resistant paint. From fresh residues of glue can get rid of water, while dried elements are removed mechanically.

For reference

Carrying of a glue mixture of Ceresit brand can be carried out at humidity of air, which does not exceed 80%. All the parameters stated in the technical description are correct at an ambient temperature of +20 degrees. At the same time, the relative humidity should not exceed 60%. If the conditions are changed, the drying out of the material and the consumption time will be different. If there is a need to carry out work on the thermal insulation of the facade during the cool season, when the thermometer column varies from 0 to +20 degrees, then the modification of the adhesive "Ceresit CT 85 Winter" should be additionally used.

Cost

Ceresit CT 85, the price of which is 620 rubles. For a 25 kg bag, is delivered in pallets. Store the mixture can be no more than 12 months from the date of manufacture.