In a pinch, a pile of bricks or water pipes can be used in place of jack stands when using hydraulic jacks true or false?

A pile of bricks can be used in place of jack stands because they will stack neatly against each other, making a solid base to hold up what the jack stands were intended for ... Water pipes are not recommended because they are round and when stacked together, or singly for that matter, would roll. Water pipes would NOT be a steady base. A pile of bricks is acceptable; water pipes are not.