8 Systems and Types of Waterproofing For You to Know!

Antonio Neves
Written by
Antonio Neves
Published in
20/2/2020
Updated
20/4/2021
8 Systems and Types of Waterproofing For You to Know!

Amidst so many systems and types of waterproofing available in the market, it is very common that engineers and architects get a little confused when it comes to choosing the best option. After all, this is a very specific subject - and it takes a lot of experience to master it.

Waterproofing is an essential part of the project, being regulated by several NBR. To help you, I made a complete post for you, showing the main systems and types of waterproofing agents. Check it out!

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What are the 2 main types of waterproofing?

In general, there are two types of waterproofing on the market: rigid and flexible. The use will depend exclusively on the characteristics of the structures and the materials in which they will be applied. In other words, it is not a choice per se: if a certain surface requires flexible waterproofing, only it can be used.

For this reason, one of the most important steps in the elaboration of a project is to list the requirements of each part in relation to the type of waterproofing.

1. rigid waterproofing

It is suitable for structures that are not subjected to large movements. In addition, they cannot be exposed to mechanical stress, which can be caused by intense vibrations or constant impacts.

Generally, it is done with the application of chemical additives in mortar or in the form of rigid acrylic membranes. For this reason, to ensure complete waterproofing, it should be planned taking into consideration the aggregates and other sealing strategies of a structure.

This care is important to avoid waterproofing failures on surfaces that are subject to cracks and fissures. So, it is recommended for baldrames and wall footings.

2. Flexible Waterproofing

The flexible type is aimed at surfaces that are subject to dilatations and vibrations. The waterproofing products used here present more elastic properties. Therefore, they can conform to the structure during movement and thus cover cracks and fissures. In other words, it is the most used option in the external areas of buildings, especially in regions that are very exposed to the sun.

It is excellent for internal areas and can be applied on slabs and balconies. For commercial and industrial use, it is very suitable for suspended reservoirs and tanks. Besides the most common use which is in swimming pools.

There are two main types of flexible waterproofing:

  • the membranes, which are shaped on site by means of processes under heat or cold (emulsions);
  • the blankets, prefabricated.

In addition, it is important to remember that to increase the efficiency of the waterproofing, several overlapping layers of different materials can be applied.

Semi-Flexible Waterproofing

In recent years, a new type of waterproofing was developed: semi-flexible. For this reason, it has not yet been included in Brazilian technical standards. Therefore, it is necessary to be very careful when using it, describing it properly during the basic and executive projects.

Basically, it consists of a bicomponent material (polymeric mortar), a powder added to a liquid. When mixed, they form a mortar that is easy to apply.

Despite presenting intermediate characteristics between rigid and flexible, they are not indicated for surfaces subject to thermal expansion.

In addition, they present low mechanical resistance, which does not allow their use on surfaces subject to traction and friction, with people and equipment traffic.

What are the 6 Main Waterproofing Systems?

1. polyurethane membrane

This system is applied on site cold. Among its main advantages are:

  • minimum elongation;
  • high mechanical resistance - in some cases, it may even dispense with scratch protection;
  • high thermal resistance, maintaining its properties in the temperature range between -5°C and 90°C;
  • high chemical resistance, which prevents deterioration by various types of fluids and vapours;

For this reason, it is indicated in slab waterproofing projects.

2. Acrylic Membrane

Acrylic membranes can be cold applied at the construction site and, in the form of emulsion, can be added to mortars as an additive. Thus, they are perfectly compatible with both flexible and semi-flexible waterproofing. They can meet all your waterproofing coating demands, from positive hydrostatic pressures.

3. Asphalt Emulsion

This system can also be applied cold, as if it were a paint. Several layers can be made to improve the waterproofing efficiency. In addition, it features:

  • high adherence;
  • high hiding power;
  • quick drying.

All this will bring a lot of versatility to any challenge on your job site.

4. Asphalt Matting

Asphalt blankets are prefabricated materials, tailor-made for your project. They must be applied under heat to ensure total adherence to surfaces. They are extremely practical and quick to apply. One of their great differentials is their enormous elasticity, being one of the options for flexible waterproofing.

However, due to the emergence of cold application technologies, blankets are no longer being used as before. With this, they have lost their leadership, as a few years ago they were the most popular waterproofing products in the market.

5. Polymeric mortar

The polymeric mortar is composed of cement, mineral aggregates and acrylic polymeric additives. As explained, it is a bicomponent system and should be mixed, proportionally, as indicated by the manufacturer. When dry, it becomes an excellent semi-flexible, flexible or rigid waterproofing.

Due to this versatility, this type of waterproofing is recommended for both positive and negative pressure hydrostatic waterproofing.

Its application is done cold with the use of rollers and polyester mesh for structuring. The joiner should be very careful about the curing times when performing each coat. As it presents low superficial mechanical resistance, it is recommended the use of a protective coating, in case of traffic.

6. Water repellents

Water repellents are products that can be applied to plaster, mortar and concrete. Their waterproofing action is quite interesting: they have a surface tension of the structure, so when they come into contact with the structure, they drain quickly. For this reason, they are also called water repellent.

They differ from most waterproofing products in that, in addition to preventing water from entering the structures, they also prevent it from adhering, leaving the surface completely dry. Therefore, they are ideal for places that must always remain dry.

However, this is a rigid waterproofing system, and cannot be used in locations subject to high thermal expansion or mechanical stress from vibrations.

A great advantage of the material is its low cost, allowing its use in works of different budgets. It is commonly applied in exposed concrete, exposed bricks and in building facades with textures or ceramic coatings.

As we have seen, the right choice of systems and types of waterproofing is essential for the success of your project. That's why it is so important to count on specialized help on the subject. Besides, choosing products from the best brands will be essential so that you don't have any problems in the future.

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