In even the most violent tornadoes, there is only a pressure drop of about 10%, which is about . Not only can this difference be equalized in most structures in approximately three seconds, but if a significant pressure differential manages to form, the windows will break first, equalizing the pressure. Additionally, as the windows are the most fragile parts of a house, in a significant tornado flying debris will likely break enough windows to equalize any pressure difference fairly quickly. Regardless of any pressure drop, the direct effects of a tornado's winds are enough to cause damage to a house in all but the weakest tornadoes.