STRATEGIES FOR CONTROLLING CRACKS IN RESIDENTIAL BUILDINGS
The study was designed to find out strategies for controlling cracks in residential building, in Niger south senatorial district. Among the specific purposes of the study were determining the availability to facilities for controlling cracks in residential building, determine the methods of detecting cracks in residential building, and determining the availability of personnel for detecting cracks in residential building and also the strategies adopted to improve the control of cracks in residential building in Niger south senatorial district. The study adopted description survey research design and the area of the study is Niger south senatorial district. The population of the study includes 258 respondents made up of 120 building team, 50 clients, 50 engineers and 38 supervisors. The instruments for data collection a 25-item structured questionnaire designed to elicit responses to the research questions. The instrument was validated by three experts who embellished it in term of both face contact validity while the reliability coefficient of the instrument was established using test re-test which yielded the coefficient of 0.78. Data for the study were personally collected by the researchers and three trained research assistances. While mean statistics was employed to analyze relating to research questions.1-4 based on the findings of the studies. The following recommendations were made, Correct mix ratio should be properly follow to avoid building cracks. Walls and other parts of the bridling should be properly cured after being constructed. Soil test should be conducted so as to ascertain the strength of the soil. There should be proper design to avoid building cracks. Use of unclean materials should be avoided.
1.1 Background of the study
Modern building of engineering structure are complex and require Architect, structural engineers, quantity surveyor, good contractor and supervisors for detailed planning, safe design and efficient use of appropriate material. When these requirement are not made adequately, failure becomes more probable? According to Evelyn (September – 2004) cracks in building elements may constitute a defect in a variety of ways. In many cases a particular crack occurrence may result in more than one type of defect. A serviceability defect and an appearance defect. And according to Shri M.M Goyal (2004) occurrence of various crack patterns in the building during construction and after completion, when it is subjected to super imposed loads and during service life, is a common phenomenon. A building component develops cracks whenever the stress in the components exceeds its strength. Stress in the building components caused by external applied forces, such as dead, live, wind or seismic leads, foundation settlement e.tc or it could be induced internally due to thermal movements, moisture changes, elastic deformation, chemical action e.t.c
The occupants of buildings may served as good tenants or occupants, Since their knowledge of the facility in many ways have contributed in checking failure and defects in residential buildings. It is important for the tenants to understand the causes of cracks in structures e.g.
Non structural cracks – these are mostly due to internally induced stresses in building material and do not endanger safety of a building but may look unsightly. Or may create an impression of faulty work or may site a feeling of insatiability. In some situation due to penetration of moisture through them, non structural cracks may spoil the internal finishes thus adding to the cost of maintenance or corrode the reinforcement, thereby adversely affecting the stability of the structure in long run, e.g vertical crack in a long compound wall due to shrinkage or thermal movement.
Cracks may appreciably vary in width from very thin hair crack barely visible to naked eye to sapling crack. Depending upon the crack width cracks are classified as: thin crack – less than 1 mm in width, medium crack- 1 to 2mm in width, wide crack – more than 2mm in width and crazing – occurrence of closely spaced line cracks at the surface of a structure or material.
The cracks that occur are of uniform width some are narrow at one end gradually widening at the other, the above pattern of cracks usually occur on the surface of plaster or rendering of the structure of building, and those patterns some occur on the walls of the building such as; straight, toothed, stepped or map pattern. The random type crack may be vertically or horizontally or diagonally e.t.c
Therefore, there is need for the occupants of the residential buildings to periodically examine and critically assess the stability and ability of the structure of their buildings.
1.2 Statement of the Problem
Crack is a kind of universal problem of building and if not checked may destroys the foundations or walls and affects the building artistic. It also reduce the durability and stability of the structure of the buildings.
Purpose of the Study
The purpose of this study is to identify strategies for controlling cracks in Niger south senatorial district. Specifically, the study is to;
i. Determined the conceptual frameworks on cracks in buildings.
ii. Determined the factors that contribute to the causes of cracks in residential buildings in Niger South Senatorial district.
iii. Determine ways of eliminating cracks in residential buildings in Niger South Senatorial district.
1.3 Significance of the Study
The findings of this study will be beneficial to professional in the building industry such as builders, quantity surveyor etc The study will also be useful to contractors, designers of buildings and the society at large.
Show-et’ al (June 2006) maintained that a mixture or mix that is richer in cement may be necessary in order to meet the requirement of comfort ability, surface finish or long term durability
The study is also importance as it would led to better understanding of how to control cracks in residential buildings in Niger south senatorial district municipal such as: Bida,lavun, Lapai, Mokwa and surroundings and to have the better knowledge of the constituents and materials and types of foundation that will suit particular type of soil.
1.4 Research Questions
The study of the crack in buildings is of importance, because it help the builder and civil engineers to know the causes and manifestation of cracks and how they can be avoided.
The following are research questions:
i. what are the conceptual frameworks on cracks in buildings?
ii. What are the factors that contribute to the causes of cracks in residential buildings in Niger South Senatorial district?
iii. What are the possible ways of eliminating cracks in residential buildings in Niger South Senatorial district?
1.5 Scope of the Study
This research is limited to strategies of controlling racks in residential buildings in Niger South Senatorial district which covered the following: Bida, Lavun Lapai and Mokwa local government area of Niger State.
The study is restricted to technical ways of controlling cracks its causes, remedies and possible ways of eliminating them.