How to Seal a Garage to Prevent Flooding

Things You'll Need

  • Threshold strip

  • Wire brush

  • Stiff broom

  • Measuring tape

  • Utility knife

  • White chalk

  • Heavy-duty adhesive

Using threshold seals on the bottom of garage doors will keep water out.

Flooding can cause costly and vast damage to your home. A commonly overlooked space within the garage is the bottom door seal located on the garage door. This section of the garage door typically has a small rubber seal. Although this rubber seal is in place, it is not adequate protection for keeping out excessive rainwater. When water from heavy rains breaches this thin seal, the entire garage can become flooded in a short amount of time, damaging belongings within. You can easily seal the garage by installing a threshold strip that prevents water from coming into this area.

Step 1

Raise the garage door to the open or up position. Clean the area of the garage floor that is in between the two door tracks with a wire brush. Use a stiff broom to sweep the loose particles and debris out from this area.

Step 2

Stretch a measuring tape between the two garage door tracks and measure the width of the floor threshold. Measure this space twice to ensure proper measurements. Write the measurements on paper and transfer these measurements to the threshold piece. Cut the threshold piece with a utility knife according to marked measurements.

Step 3

Set the threshold piece on the garage floor, in the space between both door tracks. Close the garage door so it closes over the threshold. Push the threshold piece away from you so the hump sits up against the door.

Step 4

Trace the threshold's edge onto the garage floor with a piece of white chalk. Raise the garage door, making sure not to move the threshold piece out from its position. Use the white chalk to trace the opposite edge of the threshold onto the garage floor.

Step 5

Remove the threshold piece and set aside. Squeeze a 1/8-inch-thin bead of heavy-duty adhesive within each inside edge. Use a zigzag motion to apply more adhesive in between the two thin lines of adhesive.

Step 6

Set the threshold piece on top of the adhesive beads, keeping the edges lined up with the chalk lines. Push the threshold piece firmly down onto the adhesive for an even spread. Adjust the threshold with your hands to make sure it sits between the chalk lines.

Step 7

Close the garage door and allow the adhesive to dry for 24 hours. Do not drive over the new threshold until the adhesive has fully dried, after the 24 hours.