Waterproofing of building structures, engineering structures and technological surfaces is an important condition in protecting the object from water. Penetrating agents are considered the most effective solution to this problem, as they form a dense water-repellent layer. The material is a dry waterproofing, which is prepared according to the principle of a building mixture, after which it is applied to the work area.
Purpose of the insulator
The intended purpose of the material is to provide a waterproof coating inside and outside the premises on crack-resistant and non-deformable surfaces. Depending on the specific composition, there may be contraindications to the use of waterproofing in relation to mineral and gypsum substrates. Most often, the material is involved in the following works:
- External and internal protection against water of underground and buried structures.
- The sealing of voids and holes in the masonry of old structures and buildings.
- Finishing wet rooms for the subsequent application of tiled cladding. As a rule, dry concrete waterproofing is used, which can be combined with sanitizing plaster.
- Protection of treatment and hydrotechnical facilities, constantly operated in conditions of contact with moisture.
- Waterproofing of reservoirs, pools and tanks intended for the maintenance of domestic drinking water.
In some cases, special requirements may apply for the use of different modifications of the insulator. For example, the same deformable substrates are treated only with an elastic waterproofing mass on a two-component polymer-cement base. If necessary, individual qualities are enhanced by additives - for example, to improve frost resistance, elasticity and strength.
Operating principle
The mixture has a penetrating effect, forming a reliable water-repellent layer with the surface structure of the target material. This effect is achieved due to the special composition. The standard formulation involves the inclusion of cement, silica sand and active chemical elements with particle size distribution. In the process of dissolution, the ions of the mixture penetrate through micropores into the structure of the same concrete and crystallize. As a result, chemical reactions lead to the formation of a barrier to water and moisture. At the same time, dry cementitious waterproofing mixtures can interact with metals in different ways. A reaction with calcium ions of reinforcing rods, as well as aluminum inclusions, is usually assumed. The salts and oxides contained in the concrete structure form insoluble needle-shaped crystalline hydrates as they interact. The network of such crystals is randomly located, filling microcracks and capillaries up to 0.5 mm in size. Due to the surface tension of aqueous media, fluid filtration through the structure is blocked. The resulting network of crystals forms a common monolithic structure with concrete, increasing its strength characteristics.
Varieties of material
The methods for using hydroinsulators vary, causing different requirements for the characteristics of the mixtures. As a rule, the following types of dry waterproofing are distinguished:
- Smear. It is used to protect the material of construction from external hydrological influences.
- Grouting. Used for seams, joints and joints of structures. In professional construction, this is a typical means of sealing interpanel nodal connections.
- Grouting repair. Used in sealing local leaks. A kind of sealant that can be used as a means of eliminating existing holes, etc.
- Cement additive. Even at the stage of creating the mortar, the mixture is introduced into the mass, acting as a full-fledged component of the future design along with the same cement or sand.
Preparation of the base for application
The working surface must have a reliable, even and cleaned structure. Glossy coatings should be sanded with an abrasive, otherwise the active components will not penetrate the material. Also, the surface gets rid of grease stains, efflorescences and traces of the previous finish. On the other hand, dry waterproofing does not tolerate large pores and cracks. Such surface defects must be expanded and repaired with a primer for concrete, and only after polymerization proceed with work. For example, weathered masonry joints are embroidered to a depth of about 2 cm and filled with plaster or cement mortar. Deep losses in the masonry should be replaced by new segments or completely repaired with mortar.
Mixture consumption
The waterproofing mass is prepared from two components - directly dry active mixture and water. For 25 kg (normal filling volume), 6-7 liters of pure water are enough. As for the calculation of the dry waterproofing mixture according to the consumption for a specific area, it depends on the type of composition and the degree of humidity in the room. So, for places with a high moisture coefficient, an ordinary solution is used in a volume of 2.5-3 kg / m 2 with a layer thickness of 2 mm. If a room with a pressurized aqueous medium is serviced, the flow rate increases to 5-6 kg / m 2 with a laying thickness of 5 mm. In the case of elastifier compositions, the volume is 0.8-1 kg / m 2 .
Insulator Application
Stacking is performed in several approaches, each of which must be completed by careful leveling. It’s better to start work with a mackerel brush, and apply subsequent layers with cross movements with a brush and spatula. When working with hardened layers, a problem may arise in reducing adhesion. This happens if the breaks between sets are more than 12 hours. Special additives will help to compensate for the lack of coupling, but it makes sense to add them only during the preparation of the solution. When using dry waterproofing for fillet welds, the protective structure is complemented by a waterproof tape. This consumable is usually produced by the same manufacturers of insulation materials. Tapes with an adhesive backing are also laid in other problem areas, further acting as a reinforcing lining. The laid mixture dries completely after 3-5 days.
Recommendations for the progress of work
Application of the solution is preferably carried out at temperatures of 5-30 ° C. If the work is carried out in the open, then after installation, you should consider external protection from the sun, rain and wind. When waterproofing the floor with a dry penetrating mass, it is important to provide mechanical protection of the treated structure. For this, after hardening the laid mixture, special coatings based on polymers and composites are used. A good solution would be to use bitumen mastic, but with the same water-repellent effect.
Conclusion
Penetrating insulation is famous for its many advantages from high vapor permeability and environmental safety to resistance to alkaline and salt effects, which makes it an attractive solution for external use. But it is important to remember that this is not a permanent defense. For example, a dry mix for waterproofing concrete should be laid at intervals of several years. This can be a problem in cases where the surface has a decorative finish, which will also have to be replaced. The temperature requirements should also be considered. Many manufacturers set a rigid framework for the use of such insulators in freezing conditions.