Alan owns an investment property from which he derives rental income. The investment property was constructed by a main building with a separated garage adjoined to the building. The current old iron roof on the main building had been repaired number of times during past years, therefore; Alan has decided to replace the entire old rusty iron roof on the main building only with CHEAPER cement tiles. Explain, with reasons, whether the replacement of the rusty iron roof on the main building with cheaper cement tiles is deductible as a repair expense. Make reference to the relevant sections of Income Tax Assessment Act or any common law case if available in your explanation.