hit it with fist, if it breaks and crack, it is plaster,
if it hurts your fist ( almost breeding, and bruise), likely it is concrete.
To double confirm, ask your agent to hit it again, see if both experience the same thing.
Don't try the above. just kidding, best go for a builder report, it will give you a better answer. 作者: 冬天的风 时间: 2016-4-17 20:04:30