The right choice of the waterproofing material and laying technology is mainly dependent on the project specifics.
When working with foundations, the most suitable is the bitumen waterproofing, which is applied in two layers – both under the foundation and on the basement walls. The most widely used is the SBS bitumen waterproofing. The waterproofing of the basement walls is protected with XPS thermal insulation and a drainage membrane. Sometimes synthetic materials are used in practice, most commonly those being the PVC membranes without UV protection. They are used much more seldom than the bitumen ones, as the likelihood of injury is significantly larger and they therefore need additional protection. Of great importance in the implementation of the overall underground levels waterproofing system is the correct choice of material for the processing the working joints between the foundation and the basement walls and for the processing between the individual casting stages of the basement walls.
Another method for underground levels waterproofing is the use of plastered waterproofing – both cement and bitumen based. They are relatively less commonly used and less reliable. Their main disadvantages are related to the cracks that appear in the building’s subsidence over time and with more difficult processing of the working and expansion joints.
In general, the global experience has demonstrated that the most reliable and accordingly most widespread is the waterproofing made with rolled bituminous membrane.
When stopping leaks in the underground levels of buildings, after the backfill has already been completed, the most widely used are injection resins and crystallizing cement-based plastered waterproofing.
At terraces waterproofing, the most widely used are bitumen membranes, particularly for areas over 20 m2. Cement-based plastered waterproofing materials are also used, but they are recommended for small terraces of up to 20 m2.
Of great importance for the quality performance of the waterproofing works on terraces is the protection of the waterproofing membrane with additional cement screed or concrete.
Synthetic membranes find a more limited application in outdoor terraces waterproofing.
With terraces waterproofing, it is highly recommended to perform a water test before applying the protective screed and the finishing coating.
The quality waterproofing system installation in roofs construction depends largely on the structural and architectural features of the building. For example, buildings with metal construction and flat roofs are most often made with layered installation of vapour barrier, thermal insulation of stone wool and waterproofing of TPO or PVC membrane. The most widely used system is a TPO or PVC membrane with mechanical fastening. Relatively less often the so-called ballast systems are used, in which the membrane is protected from UV rays and wind impact by applying a layer of river gravel.
In buildings with reinforced concrete load-bearing structure, two-layer bitumen systems are most often used. In them, thermal insulation (most often XPS) is applied over the reinforced concrete slab, followed by cement screed or concrete for slopes, and finally two layers of bitumen roll waterproofing are laid. In such buildings, synthetic membranes are also used, especially for roofs with large areas and a relatively small number of details. Plastered waterproofing based on bitumen and polyurethane is used relatively rarely.
In tunnels waterproofing, almost only PVC membranes are used. The protection of the membrane from mechanical damage is most often carried out by applying geotextile in two layers – respectively on the side of the primary and on the side of the secondary lining.
An important role for the waterproofing system overall reliability is played by the installation of PVC WaterStop tapes, which allow leaks localization only in a certain area in case of possible waterproofing compromising. This localization allows precise leaks removal by resins injection in an extremely short time.
Bridges waterproofing is always made of single-layer rolled bitumen waterproofing with very high strength and temperature indicators. The most important factor for the correct implementation of the waterproofing is the humidity of the base. If the normative requirements for low humidity of the base are not observed, during the hot asphalt laying vapours are formed, which peel off the waterproofing from the base and form air balloons. After the waterproofing application, tests are always performed to prove the good adhesion of the waterproofing to the base.
Landfills and tailings ponds
Landfills and tailings ponds waterproofing is used in order to prevent the soil from the infiltration of harmful substances. In this area, only HDPE membranes are used in combination with bentonite waterproofing and drainage geo-composites.
Waterproofing systems in tanks can be built using all types of membranes – synthetic, bituminous and plastered. The most common practice is the application of synthetic membranes.
There are two types of tanks requiring the construction of waterproofing systems – for drinking purposes and for fire purposes. Each type has its own specific requirements and norms regarding the materials utilized and the technology used.
Drinking-water tanks must be implemented with synthetic materials, specially designed for this type of objects. The implementation of waterproofing systems in tanks for firefighting purposes does not require the use of strictly defined materials and this type of tanks are waterproofed with synthetic, bituminous or plastered membranes.