I hate bosses like yours. He seems to want to keep his bill simple at your expense.
The worker himself in most cases would not be responsible for the durability of the built wall, but the foreman. He will stop reemploy someone whos walls fall apart, but there would hardly be a way to force him fix the wall on his own expense in Austria. Margin for errors comes with an price, the price here is a higher price for building. There are enough ways left to exploit workers.