My garage letting in water under the up and over, sheet metal door has become more of a problem since adding new tools which I'm extra keen to protect. I did see on line a synthetic strip with a hump to stop the water and a Yellow stripe as a trip warning. Trouble is the gap between the bottom of the door and the floor is too large for the bottom of the door to meet the hump as it should. There are larger version of this strip but it would be too wide to stick down properly because of variations in ground level.
My question: Is there usually a way of decreasing the distance between the bottom of these doors and the floor without major turmoil?