Siqueira – 131 Proceeedings of the RCI 21st International Convention Roof Consulting in Brazil Roof Consultants Institute Firmino S. de Siqueira Filho Rua Canoas, Brazil ABSTRACT Construction and roofing in Brazil have a strong influence from southern European culture, due to the colonial influence from Portugal, Spain, Italy, and France since the 1500s. The early 20th Century brought in reinforced concrete technologies rather than steel structures. Typical constructions are: • Urban concentration of concrete structured high rises. • Densely populated coastal cities with waterfront buildings most valued. • Local codes meant to avoid greater damage to city centers, determined from the 1970s that construction be restricted. Large concrete decks forming plazas and playgrounds over basements and garages were a consequence. • Garden and rooftop leisure areas are typical, as in most of Brasil it’s summer all year long. • Leaks and concrete deterioration developed as poor practies were used. • Design and consulting have grown as a consequence of problems owners and developers faced. New products also required expertise to be specified. This paper will give examples of this development and show the state of the art in 2006. Slides from typical Brazilian skylines and typical buildings will be shown. SPEAKER FIRMINO S. de SIGUEIRA FILHO is a civil engineer, having graduated in 1975, and since dedicated hiscareer to roofing and waterproofing. In 1977, he founded a roofing contracting business that has installed over 3000 roofs throughout Brazil, from the Amazon to the very south; from the coast to the pre-andean plains in the west, including shopping centers, hydroelectric generation power houses, underground structures, and common rooftops in urban areas. In the past 20 years as a consultant, he has designed and inspected roofs all over Brazil, mostly in the southeastern cities of Rio, Sao Paulo, and Belo Horioznte, as well as in Brazil’s capital, Brasilia. Siqueira – 132 Proceeedings of the RCI 21st International Convention INTRODUCTION: To understand the Brazilian market, one needs to know the difference between how roofing and waterproofing are dealt with there. Many aspects of the country lead to a different approach compared to what is current in the U.S. These aspects are: Geography Brazil is a large country, stretching from the parallel 10 north to 37 south. The tropic of Capricorn crosses the city of Sao Paulo in the south, leaving only 10% of the territory under a mild temperate climate. The other 90% is tropical, from a dry northeast to flood plains in the lowlands at the western central states. In the tropical heights to the southeast, it is torrid in the northern rain forests of the Amazon, where the world’s largest rainforest lies. In the south, one can find cold weather, where snow may fall a few times a year up in the mountains, though it does not stay. Temperature may reach -10°C (14°F) on the coldest days. This means that in most of the country, roofs are built only to shed water and not to accomplish other functions, such as provide heat and supply vapor barriers. Ceramic, cement, and metal tiles perform this simple task fairly well, resulting in basic assemblies, low-cost materials, easy maintenance, and light structures. Naturally, most roofs are pitched, with or without gutters and appropriate piping and drain work. Any observer will notice that these pitched roofs do not require insulation materials nor utilize any kind of waterproofing membrane, as they simply shed water. High ceilings or ventilation provide internal heat comfort. As a consequence, anyone involved in these kinds of roofs does not deal with any waterproofing, which is completely associated with the flat roof trade, where waterproofing membranes are installed, and sometimes insulation is used. Materials and techniques So what we refer to when we discuss waterproofing in Brazil is the flat roof, dead level, or low slope, where APP and SBS-modified bitumen membranes or synthetics (such as PVC, EPDM, Butyl, etc.) are used. Roof construction and assembly are not a part of the waterproofing market, reducing their share of the construction market mostly to membrane installation and protection layers. Different professionals design, inspect, manufacture, and install each kind of roofs. Types of structures Most residential high rises, housing, and small buildings are constructed of clay or concrete bricks, concrete structures and decks, ceramic, metallic, or fibercement tiles. These are of metal and industrialized concrete for industrial or large commercial buildings, such as shopping centers. Construction involving waterproofing materials is mostly lowslope or dead-level reinforced concrete decks and structures. Slowly, steel and industrialized concrete structures are appearing, pointing to the need for new solutions in the coming years. CONSULTING AND DESIGN – ING Until the 1960s, most Brazilian decks were waterproofed with felt-reinforced, hot-mopped, oxidized bitumens imported from England or the U.S. Proceeedings of the RCI 21st International Convention Siqueira – 133 Roof Consulting in Brazil Picture 1 – National Theatre, Brasilia. At that time, construction of the subway networks of São Paulo and Rio de Janeiro, plus the modern architecture of Oscar Niemeyer, one of the world’s leading 20th century architects, culminating with the construction of Brazil’s new capital, Brasilia, as an upand- coming modern city and a landmark in urban planning and design. This brought innumerable new and unusual types of roofs with their challenges to our technicians, because materials used up to that point did not perform well enough to provide safety and leak protection. As a consequence of this evolution, in the late ’60s and early ’70s, new materials were introduced into the market: • Butyl rubber membranes. • Liquid-applied Neoprene and Hypalon membranes. • Modified bitumen pre fabricated membranes. • Polymeric admixtures to concretes and mortars. • Epoxy resins. • Others. This is the period known as the Economic Miracle of Brazil, due to easy international credit and strong economic growth supported by military dictatorship. It lasted for around ten years. Construction experienced a boom of 8-10% growth per year. As waterproofing technologies were primitive and contractors were outnumbered by work and inexperienced in new technology, technical needs were not met due to a lack of supply. Countless roof failures were therefore registered in the following years. Roofing contractors, a few knowledgeable professionals, and some manufacturers were the only source of support for owners facing leakage problems. And since there were so few of them, new mistakes were committed. This was the root of the roof consulting activity in Brazil. Some landmarks were then established: • The first work group to discuss standards for waterproofing was formed in 1970. • The first Brazilian standards, NB 279, were published in 1975. • In 1975, the Instituto Brasileiro de Impermeabilização (IBI – Brazilian Institute of Waterproofing), was formed. • In 1978, the first Symposium of Waterproofing in the country was held in São Paulo. It issued a resolution determining that all construction had to have a specific project for waterproofing. • New symposia followed every two years, stressing Siqueira – 134 Proceeedings of the RCI 21st International Convention Picture 2 – The world’s second largest hydroelectric plant, in Tucurui, Amazonia, Brazil. Picture 3 – Business complex in Sao Paulo. the importance of a specific design, and generation data to support the designers. So far, 12 symposia have been held, some with significant international participation, and all under IBI’s organization. As an immediate consequence of this growth, new industries were established, and new products came to the market. Owners and general contractors were facing the problem of choosing among the many options available. Professionals with the skills to provide this support were found in the crews of roofing contractors and from industries as they left their jobs and became independent advisors. Engineering schools started holding conferences on topics relating to waterproofing and the losses caused by leaks. One university created a full course for waterproofing in the Civil Engineering graduation course as an independent discipline (Universidade Fumec, Belo Horizonte, MG Brazil). Industries kept pace with international technologies and through participation in NRCA and IWA events, local industries remained updated. The more it developed, the more consultants grew in importance. Again, unprepared professionals came into the market as there were not enough skilled people to respond to the demand. New problems were generated on a lesser scale, and the importance of independent, thorough advice was clearly identified by the construction industry. HOW DESIGNING IS CONDUCTED IN BRAZIL: Different professionals, different approaches. Standards try to link these differences to a specification that can be read and understood by all. Despite all the differences, after living through many different projects and professionals in all kinds of jobs, we can identify a pattern that is present in most cases. We dare to call it a “Method,” empirical as it may be, and it is now undergoing study for a dissertation for a master’s degree at the University Fumec. We shall describe it as follows: 5 Q METHOD Description An approach by which it is possible to reach a very accurate response to specifying how to waterproof an area, considering all aspects – technical, legal, and economic, by formulating five basic questions. How it is Formulated Five questions are proposed. By searching for the answers, we reach one that best fits the needs of the case under study. They are: • Q1 – Where? • Q2 – When? • Q3 – How Long? Proceeedings of the RCI 21st International Convention Siqueira – 135 Picture 4 – Pool at beach resort on tropical northeastern coast. Picture 5 -Rooftop garden on a house. • Q4 – How? • Q5 – How Much? By short analysis of each, giving directions on the technical basis one must use to support the answers, we arrive at the following descriptions: Q1 – Where? Brazilian standards define waterproofing as a “building protection against humidity.” The presence of water on unprotected areas or its passage through structures causes deterioration. So, by analyzing where water cannot be present in a defined building, one can determine where to install waterproofing and justify it in solid argument. Q2 – When? The timing of the installation is another key aspect for definition, as any membrane may be placed under greater or less stress according to the order it is installed in the construction. Obviously, if the installation takes place at the early stages of a construction, much more interference will be expected, and many loads, other than those the building is planned for, will be active for a certain period of time. Cranes, material transportation, scaffolding, material falls, etc., may be placed over the membranes, and different resistance or protection layers will be required. On the other hand, if the membrane is the last product to enter the jobsite, much less is expected to put it at risk, meaning different solutions. Q3 – How Long? How many years of service life should be the ideal for the building? However polemical this topic may be, some of them can be clearly defined with a strong influence on the material choice. For instance, public buildings (i.e. schools, hospitals, court houses, bridges) or any construction financed by taxes should last so that it doesn’t have to be continually redone. On the other hand, commercial, industrial, and residential constructions are likely to be retrofitted much more often, whether ifor technical or aesthetical purposes. This will greatly influence the choice of material, as service life varies from material to material. Ease and cost of maintenance will also be strong factors for a specification. And last but not least, environmental aspects have to be taken into consideration, as it requires a deep analysis according to the CIB/ RILEM WG 83 report. Q4 – How? Based on the responses to the first three questions, regarding adding structural considerations such as the type of structure (concrete, steel, wood, etc.,) and the movements and loads structural engineers consider in their calculations, we can have information on which properties waterproofing materials need to have to perfectly match these solicitations. Tensile strength, ultimate elongation, adherence, puncture and compression resistance, shear resistance, and aged testing are properties laboratories can provide as routine testing is conducted on waterproofing materials. By confronting properties with structural solicitations, we can reach a very close result to what is needed. This item will require engineering knowledge and a very sound formation from the consultant, not only with expertise in waterproofing, but engineering as well. Q5 – How Much? If at this point of the study we still have more than one possible choice, the time comes to refer to costs. Then and only then will the lowest price criteria apply, solidly based on technical background. The best price will be the best choice, and it is very important to have in mind that no names or brands of materials have been necessary to reach this level of decision, which makes a reliable, if not scientific approach to a very important decision. Quite frequently, we will face situations when owners spend money without accounting for waterproofing. We can, in these cases, reverse our process, and start from the Q5 by checking what can best be done with the cash available, and clarifying what the life span and Siqueira – 136 Proceeedings of the RCI 21st International Convention Picture 6 – Holes punched by ants in a membrane. performance of materials may be. In a document where this will be boldly stated, one will be aware of the benefits and risks involved CONCLUSION Consulting and designing roofs in Brazil, although quite a young activity, relies on sound concepts, a method that is taking a scientific aspect and that is a growing and promising field for qualified professionals. It best suits those with solid engineering backgrounds who are able to understand structures and are knowledgeable of the physical and chemical properties of waterproofing materials, construction planning, and roofing contracting jobsite challenges, such as other trade interference, mobility, accesses to roof, on-site modifications and other situations. 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