Centre Wellington Garage Door Pros · Centre Wellington
Garage Door Bottom Seal Replacement: how the work is done
Garage Doors · Centre Wellington, Ontario
The bottom seal, called an astragal in the trade, is the flexible strip along the underside of the lowest door section that squashes against the floor when the door closes. On most steel doors it is a U-shaped vinyl or rubber profile whose two edges slide into the channels of a retainer fixed to the bottom rail; on wood doors it is often a flat angled strip nailed in place. Replacing it means matching that retainer and profile, fitting a fresh seal the full width of the door, and confirming it meets the floor in one continuous line so light, drafts, water and pests lose their route in.
Is the door hanging level?
A gap that is wider at one corner is often the door rather than the seal. The technician checks that the door sits square in the opening by comparing the bottom edge to the floor at both ends and looking at how each lift cable wraps its drum. A stretched cable, a drum that has crept on its shaft or uneven spring tension drops one corner a centimetre or two, and setting the door level is what closes that wedge. If the door is out of level, the adjustment is explained as its own item and done first, and the seal is then sized to the gap that remains. Getting the order right saves fitting a seal twice.
Securing the door before work begins
The opener's release cord is pulled so the motor is out of the picture, and the door is raised by hand to a height where the bottom rail sits at a comfortable working level, usually around chest height. A clamp goes on each vertical track just below a roller so the door cannot drift down while the retainer is exposed. The bottom brackets in each corner stay untouched throughout, because they carry cable tension whenever the springs are wound. With the door held and the floor in front clear, the seal and retainer can be handled like any other piece of hardware.
A clear threshold through winter
The seal closes onto whatever is on the floor, so the threshold deserves a moment when you clear the driveway. Push packed snow and the ridge of ice that forms where the door meets the slab away from the opening before running the door, and sweep salt piles and grit clear of the line so they are not ground into the strip. Park a little further in, if the garage allows, so drips from the car fall on the floor rather than at the seal. These are the same habits that protect the bottom brackets and cables in the corners.