Some door models have guide tracks made of high-impact plastic. These doors offer superior durability over standard doors, but can also prevent the transmission of heat from the outside, preventing chilled air from condensing and creating moisture on the floor.
Even when the doorway is completely covered, moisture can still form on the dock floor through condensation, especially in cold-storage warehouses. It’s important that the dock door match the thickness of the dock walls. Utilizing a thicker, insulated impactable dock door is the ideal defense in cold storage applications.
Levelers – the welcome mat to infiltration. Standard pit-mounted dock levelers provide safe trailer access for forklifts, but the pit cut into the concrete dock floor includes small gaps that act as a passageway for the weather. This presents a challenge because the loading dock, even with a closed door, is often not properly sealed off.
There is a solution for this energy loss, however. Both new and existing pit-style dock levelers can be outfitted with an advanced weatherseal system, a combination of durable open-cell foam and heavy-duty vinyl. This effectively fills the gaps around the sides and rear of the dock leveler and provides a superior seal around the perimeter.
As an alternative to pit-style dock levelers, vertical-storing powered levelers and modular dock bridges store upright when not in use. This design allows the dock door to close tightly against the concrete floor to seal in the energy and lock out the elements. Vertical levelers and dock bridges provide the added benefit of a full perimeter seal while also acting as a steel barrier when stored, protecting overhead doors from forklift assaults.
Door seals – is the parked truck bringing in more than product? Even when a forklift is working as fast as it can to load or unload, a trailer can be parked at the dock for hours at a time. Docks depend on seals and shelters to close off the gap between the dock wall and the trailer and prevent the invasion of outdoor moisture. As with damaged dock doors, a poorly specified seal or shelter also permits considerable infiltration.
Dock seals have fabric-covered foam pads that compress when the trailer backs into them, providing a tight seal around the sides of the trailer and closing the gaps between the trailer’s door hinges. Dock shelters consist of fabric attached to side and head frames to create a canopy around the perimeter of the trailer, allowing full, unimpeded access to the interior.
Galvanized steel backing offers many advantages over wood backing that is used on some models of dock seals and shelters. Wood backing has a solid mass (1-1/2" thick) that does not yield when the seal is compressed, often resulting in damage to the building. With steel backing, the solid mass is replaced with compressible foam on a steel frame. Steel backing also offers superior durability because it does not rot, split, crack, or warp. It uses plated screws with load-spreading washers in the steel to provide a stronger, more durable hold on the fabric.
Because rain and snow can build up on the roof of a truck, moisture can also spill into the dock through the top of the doorway. Dock seals and shelters can be combined with rain-sealing systems to literally wipe off moisture from the roof of backing trailers to keep it out of the dock area. These rain-sealing systems attach to the top or header of the dock seal/shelter and are fitted with a special wiper pad that sweeps rain, snow, and condensation off the roof of the trailer.
Many docks use rubber wheel chocks in an attempt to hold trailers in place during loading and unloading, but rubber wheel chocks are no match for the forces exerted by forklifts driving in and out of trailers. This force can gradually cause a trailer to “walk” away from the dock, forming a doorway gap. A powered vehicle restraint ensures that the trailer is held snugly to the dock, with the back end of the trailer fully enveloped by the dock seal or shelter.