The Importance of Water and Heat Insulation in a Potential Istanbul Earthquake

The Importance of Waterproofing and Thermal Insulation in a Potential Istanbul Earthquake Emrullah Eruslu, Chairman of the Board of Directors of İZODER - Association of Thermal, Water, Sound and Fire Insulators, made statements on the occasion of the 24th anniversary of the 17 August Marmara Earthquake, saying the following on the matter: "As İZODER, earthquakes are a sensitive point for us. Since 1999, we have continued to issue necessary warnings to relevant institutions and our citizens about the measures that should be taken against earthquakes at every opportunity. Because we know that structures collapse not from earthquakes themselves but from faulty applications and lack of supervision. As we frequently repeat, one of the most important causes of destruction caused by earthquakes is corrosion that negatively affects the load-bearing capacity of the structure. Water sensitivity constitutes one of the weakest points of reinforced concrete structural systems. Rain, snow, groundwater, moisture in the soil, water leaks from wet areas such as kitchens, bathrooms and toilets, pressurized or non-pressurized groundwater beneath the building site—buildings can be continuously exposed to water due to these factors. Water penetrating into load-bearing structural elements causes rust on the steel inside the concrete, that is, corrosion. Corrosion reduces the load-carrying capacity of the structure. For reinforced concrete structures to maintain their functions in a healthy manner throughout their design life, the entire structure must be protected from corrosion with waterproofing and thermal insulation in accordance with standards. In short, we can make our buildings safe against earthquakes by protecting iron and concrete, the main components of structures, from the adverse effects of water through insulation."

Buildings without waterproofing lose 50 percent of their load-bearing capacity in 5 years due to corrosion

Sharing data from the research of Prof. Dr. Şakir Erdoğdu, Faculty Member at Karadeniz Technical University, which reveals the relationship between reinforcement and corrosion, İZODER Chairman Emrullah Eruslu continued his remarks as follows: "A reinforcement exposed to water loses 50 percent of its load-bearing capacity after 5 years, 90 percent after 15 years, and all of it after 24 years. That is, the collapse of a structure due to reinforcement corrosion alone is possible, even without any earthquake or external factor. Following the 17 August 1999 Marmara Earthquake, inspections conducted by the Istanbul Metropolitan Municipality Damage Assessment Commission found that of 55,651 residences and commercial properties, 79 percent of which were damaged, corrosion was detected in 64 percent." [caption id="attachment_155848" align="aligncenter"] İZODER Chairman Emrullah Eruslu[/caption]

The number of waterproofed buildings in Turkey does not even constitute 2 percent of the building stock

Saying that insulation makes buildings energy-efficient, healthy, comfortable and safe, Emrullah Eruslu continued his remarks: "The Building Waterproofing Regulation, which is vital for buildings to withstand destructive factors such as earthquakes, came into force only 5 years ago. From now on, correct waterproofing application in all buildings is of great importance. We can protect our buildings by properly and completely applying waterproofing to areas of the building directly exposed to water, such as roofs, foundations and wet areas, and thermal insulation applications that prevent condensation, known colloquially as sweating. Today, 30-year-old buildings in our country are considered to have completed their lifespan, whereas our buildings should have a lifespan of at least 80-100 years. The number of buildings constructed and mandatorily waterproofed from 1 June 2018, when the Building Waterproofing Regulation came into force, constitutes only 1.5-2 percent of the total building stock. In our country, which has approximately 10 million buildings and over 22 million residences, these figures unfortunately show that we are far from where we should be in terms of the number of safe buildings," he continued.

It is estimated that 194,000 buildings in Istanbul will suffer damage in a potential earthquake

Saying that "In a scenario earthquake of 7.5 magnitude, it is estimated that an average of 17 percent of buildings in Istanbul (approximately 194,000 buildings) will suffer moderate to severe damage," Emrullah Eruslu continued his remarks as follows: "The results contained in the 'Istanbul Province Potential Earthquake Loss Prediction Update Project' report, prepared by the Istanbul Metropolitan Municipality and Boğaziçi University Kandilli Observatory and Earthquake Research Institute Earthquake Engineering Department and shared with the public on 20 October 2020, reveal the seriousness of the situation; in a scenario earthquake of 7.5 magnitude, it is expected that an average of 26 percent of buildings in Istanbul will suffer light damage, 13 percent moderate, 3 percent severe and 1 percent very severe damage. In the scenario earthquake, very severely and severely damaged buildings sustain earthquake damage that cannot be repaired, and there is a need to demolish and rebuild buildings at these damage levels. On the other hand, it is noted that for moderately damaged buildings, demolition and reconstruction is mostly more appropriate than repair."

There must definitely be waterproofing and thermal insulation

Drawing attention to the fact that urban renewal to be carried out throughout the country, in particular in regions covered by the Marmara Earthquake, which scientists have pointed out is likely to occur in the near future, contains an important opportunity to construct safe buildings, Eruslu expressed his view: "In newly constructed buildings, soil investigation must be conducted correctly, the structure must be designed in accordance with its engineering requirements, it must be protected through insulation from internal and external factors, and all processes must be supervised in accordance with engineering standards."

Eruslu also issued warnings to those who will rent or purchase a new house, saying the following:

"As a first step, inquire about your building's permit status and date. Knowing that thermal insulation has been mandatory since 14 June 2000 and waterproofing since 1 June 2018 in order to obtain a building permit in our country, you can inquire about the building's insulation status. Water marks on the outer walls of the intermediate floors of the building, plaster swelling, mold and mildew formation indicate lack of thermal insulation in the structure. When walking through the residence you will rent or purchase, check all walls, particularly the north-facing ones. If you will live on the top floor, check the ceilings and also the ceiling and outer wall junctions for water marks, plaster swelling and structural cracks. If you encounter these problems, they indicate lack of thermal insulation and/or waterproofing in the building. It is not sufficient to check only your apartment. Ask whether there is a drainage system to divert water coming to the building. Always check whether there are structural cracks and whether reinforcements have been exposed. Ensure that load-bearing elements such as columns and beams have not been damaged. Inquire whether waterproofing has been done in the building's foundation. Water marks, cracks, black spots or efflorescence caused by water and moisture on curtain walls, beams or columns in the building's basement indicate a waterproofing problem in the foundation. It is possible to subsequently apply waterproofing to the building's roof and wet areas where water is used, such as toilets and bathrooms, and external thermal insulation to the outer facades. However, it should not be forgotten that it is not possible to protect the building from the harmful effects of water by subsequently applying waterproofing to the building's foundations."   You can access the 'Waterproofing Regulation Guide' prepared under the leadership of İZODER, with contributions from the insulation industry and support from the Ministry of Environment, Urbanization and Climate Change at www.izoder.org.tr.