A man may not place an oven in a house unless there is a height of four cubits above it. [If] he wished to place it in the upper story, there must be a [layer of] plaster three handbreadths [thick] beneath it, and for a stove, one handbreadth. If it caused damage, he must pay for the damage. R' Shimon says: They stated all these measurements only so that if it caused damage, he [should be] exempt from paying.