The county superintendent of education shall recommend to the county board of education for condemnation school buildings which are unsanitary and unfit for use. He shall recommend in writing all repairs, purchase of playgrounds and school sites and buildings to be erected with state, county and local aid and shall see to it that the plans and specifications and the rules and regulations of the State Board of Education, with reference to the erection, repair and equipment of the school buildings, are carefully followed. He shall approve in writing all contracts of whatever kind entered into by the county board of education.