ABNT NBR 9575 - Waterproofing - Selection and Design

3. Selection:

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Here, we enter the main theme of NBR 9575, which is the selection of the appropriate type of waterproofing to be chosen for the work.

The appropriate type of waterproofing to be used in civil construction must be determined according to the request imposed by the fluid on the constructive parts that require watertightness. The request can occur in four different ways, as follows:

1. imposed by percolating water;
2. imposed by condensation water;
3. imposed by soil moisture;
4. imposed by the fluid under unilateral or bilateral pressure.

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4. Project:

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This is the other central topic of the standard that we are analyzing, which talks about the waterproofing project.

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4.1) Preparation and technical responsibility:

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The basic waterproofing project must be carried out for civil construction works for public, collective and private use, by a legally qualified professional.

The executive waterproofing project, as well as the resulting services, must be carried out by legally qualified professionals.

Thus, in all graphic and descriptive pieces (basic project, executive project and project “as constructed”), the data of the qualified responsible professional must be included.

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4.2) General Requirements:

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The general requirements for a well-done waterproofing project involve several aspects, which we will discuss below.

Basically, when formulating a project, waterproofing must be designed so as to:

1. avoid the passage of fluids and vapors in buildings, through parts that require watertightness, whether or not other construction systems may be integrated, provided that specific performance standards are observed that provide the same conditions of Watertightness;
2. protect building elements and components that are exposed to weathering, against the action of aggressive agents present in the atmosphere;
3. protect the environment from contaminants through the use of waterproofing systems;
4. provide access to waterproofing whenever possible, with minimal intervention in the coatings superimposed on it, in order to avoid it, as soon as system failures are noticed waterproof, the degradation of structures and building components.

In addition, the project must be developed together and compatible with other construction projects, such as architecture (basic and executive design), structural, hydraulic-sanitary, rainwater, gas, electrical, cladding, landscaping and others, in order to provide for the corresponding specifications in terms of typology, dimensions, loads, tests and construction details.

The formulation stages of a waterproofing project can be divided into a preliminary study, basic waterproofing project, executive waterproofing project, and complementary services to the executive waterproofing project.

Regarding the preliminary study, a report must be prepared containing the qualification of the areas and a spreadsheet containing the types of waterproofing applicable to the project, according to the concepts of the contractor designer and developer.

As for the basic waterproofing project, it involves the following steps:

1. definition of the areas to be waterproofed and the equalization of existing interferences between all building elements and components;
2. definition of waterproofing systems;
3. quantitative survey spreadsheet;
4. performance study;
5. cost estimation.

The executive waterproofing project consists of identifying the following characteristics:

1. plans for the location and identification of waterproofing, as well as construction details;
2. specific and generic details that graphically describe all waterproofing solutions;
3. constructive details that graphically describe the solutions adopted in the architectural project;
4. descriptive memorial of waterproofing materials and layers;
5. memorial descriptive of enforcement proceedings;
6. spreadsheet of quantities of materials and services.

In addition to these requirements, there are some complementary services to the executive waterproofing project that must be adopted, namely:

1. methodology for control and inspection of services;
2. methodology for the control and inspection of services and methodology for controlling the technological tests of specified products;
3. guidelines for drafting a user, operation and maintenance manual.

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4.3) Specific Features:

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In this topic, the standard states that the waterproofing systems to be adopted must meet one or more of the following requirements:

1. resist static and dynamic loads acting under and on waterproofing, such as: puncturing, cracking, tensile rupture, wear, detachment and crushing;
2. Resist the Effects of Dilating Movements and Retreenchment of the substrate and coatings, caused by thermal variations, such as: cracking, tensile rupture and detachment;
3. resist degradation caused by climatic, thermal, chemical or biological influences, such as: wear and tear;
4. resist hydrostatic, percolation, water column pressures and Wetness of soil, as well as detachment caused by loss of adhesion;
5. present adhesion, flexibility, resistance and physical and mechanical stability compatible with the requests provided for in the other projects;
6. resist the attack and aggression of ornamental plant roots.

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4.4) Construction details:

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In this last topic, NBR 9575 contains some important details that must be addressed by executive waterproofing projects, namely:

1. The slope of the substrate of the horizontal areas must be defined after flow studies, with a minimum of 1% towards the water collectors. For gutters and internal areas, a minimum of 0.5% is allowed;
2. The collectors must have a diameter that guarantees the maintenance of the nominal section of the pipes provided for in the hydraulic project after the waterproofing has been carried out, with a minimum nominal diameter of 75 mm. The collectors must be rigidly attached to the structure. This procedure must also be applied to collectors that cross inverted beams;
3. a socket must be provided in the vertical planes to embed the waterproofing, for the system that so requires it, at a minimum height of 20 cm above the level of the finished floor or 10 cm from the maximum level that the water can reach;
4. in the border areas between waterproofed outdoor areas and internal areas, there must be a height difference of at least 6 cm and a physical barrier must be built at the limit of the internal line of the subframes, frames and stops, for perfect anchoring of the waterproofing, with a slope to the external area. It must be noted the execution of fittings appropriate to the type of waterproofing adopted and additional seals on the frames, counterframes, stops and other interfering elements;
5. any installation that needs to be fixed to the structure, at the waterproofing level, must have specific finishing details and waterproofing reinforcements;
6. all pipes that cross the waterproofing must be fixed to the structure and have specific finishing details and waterproofing reinforcements;
7. hydraulic, electrical, gas and other pipes that pass parallel over the slab must be run over the waterproofing and never under it. These pipes, when apparent, must be executed at least 10 cm above the level of the finished floor, after the waterproofing and its accessories have been completed;
8. When there are pipes embedded in Masonry, adequate protection must be provided for fixing the waterproofing;
9. the pipes outside the walls must be spaced at least 10 cm apart from each other or from the vertical planes;
10. The pipes that pass through the Waterproofed Slabs they must be rigidly attached to the structure;
11. when there are built-in hot water pipes or floor heating systems, adequate thermal insulation of these must be provided to carry out waterproofing;
12. every encounter between vertical and horizontal plans must have specific waterproofing details;
13. the vertical planes to be waterproofed must be executed with elements rigidly attached to the structures, up to the final end of the waterproofing, with the necessary reinforcements being provided;
14. waterproofing must be performed on all areas under the filling. It is also recommended to execute it over the filling. Fluid flow points must be provided at both levels;
15. sharp edges and corners of the areas to be waterproofed must be rounded whenever waterproofing so requires;
16. the mechanical protections, as well as the rear floors, must have retraction and thermal work joints filled with deformable materials, especially when meeting different plans;
17. As Expansion Joints they must be water dividers, with higher dimensions when leveling the base, and specific details must be provided, especially regarding the folding of their opening in the mechanical protection and on the subsequent floors;
18. All areas where there is a gap must receive Waterproofing on the Slab upper and is also recommended on the lower slab;
19. in places where waterproofing is carried out on a subfloor, it must be perfectly adhered to the substrate.
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Today, we talk about NBR 9575, which deals with waterproofing selection and design, very important steps that must be prepared following all the recommendations established by the standard that we explain here today. Therefore, read carefully and reread it as many times as necessary for the project to be very well done so that, in this way, you can guarantee the best result in your work! And of course, count on Blok For any challenge!