Garage door threshold seal installation should always take place under warm and dry conditions. If you have trouble with rain water leaking into the garage you should consider using garage door threshold seal. Unlike other seals, threshold seal adheres directly onto the concrete floor. Liquid nails and outdoor caulking provide a water tight seal that can keep out water and other debris. Threshold seal comes in a kit made to fit all standard garage door sizes. Always be sure to measure the width of your garage door opening. Threshold seal is  always best used in combination with bottom astragal.  Here are some basic installation instructions to get you started.

Installation Instructions

Threshold seal should be installed on a clean and dry surface. If necessary, use an angle grinder to clear dirt and other debris from the floor. Make sure the temperature is at least 40 degrees before installation and always make sure you have a smooth surface. This product should not be installed over cracks, asphalt, painted or finished surfaces. An angle grinder can be used to notch and clean off the surface.

  1. Move the garage door into the open position , centering the threshold seal between the vertical tracks. Trim the seal down to meet the correct door width. Make sure the bump side of your threshold is on the inside of the garage door. That will allow the bottom seal on your garage door to hit the outside edge of the hump. This allows rainwater to run down off the face of the door.
  2. Lower your garage door down onto the threshold seal. Push the seal up against the back of your garage door. You may need to notch out the seal on each side of the door to get ensure a tight fit. The 45 degree hump should be tucked up against the back of the garage door in the closed position.
  3. Using a pencil trace around the outside of the threshold seal from end to end. Carefully raise your garage door into the open position without moving the threshold seal.
  4. Remove the threshold seal and apply the supplied adhesive to the concrete floor. Liquid nails from your local hardware store can be used if nothing is supplied in your kit.
  5. Place your threshold seal on top of the adhesive and between the pencil lines. Press the seal firmly into place and apply continuous pressure. Inspect the seal to make sure it is in the correct position again.
  6. Close the garage door on top of the threshold seal. Make sure the bottom of the garage door is hitting on the inside edge of the hump on the seal. You can adjust the position for a short period of time.

Leave the threshold seal in place for at least 24-hours. Keep the garage door closed during this time with constant pressure on top of the seal. It is not recommended that you drive over the seal while the adhesive sets. You also need to make sure you have a dry weather forecast to let the adhesive dry properly. For extra water protection consider caulking both the inside and outside edge of the garage door threshold seal. Lastly, you may need to adjust your limits, forces and locks to compensate for the new garage door position.