When we moved to this suburban house in 2001, there were countless repairs starting from the roof down to the fence. It was a learning stage for us since we were not used to hiring people to do such repairs. And in the process of the continual house repairs, we learned that carpenters, masons and other repairmen has the penchant for buying excess materials. We are always left with extra hollow blocks, galvanized sheets, sacks of cement, etc. After years of such experience, my husband had learned to double check the estimated count of the needed materials for the house repairs. There was even a time when the worker argued with my husband why he listed 50 hollow blocks when only 20 were needed.... the 30 was allowance for breakage, huh. That's the style of the workers here.