- Foam dock seals compress against the back of the trailer for a tight closure, but suit a consistent fleet and can narrow access at the edges of the opening.
- Retractable shelters drape curtains around the trailer, accept a wide mix of vehicle sizes and leave the full trailer opening clear for loading.
- Inflatable shelters inflate cushions around the docked trailer for a close seal across mixed fleets, at a higher price and with a fan to maintain.
- Bumpers, wheel guides and careful docking protect any shelter or seal, because trailers that dock off-centre or too hard tear curtains and wear pads quickly.
What is the difference between a dock shelter and a dock seal?
A dock seal is a set of foam pads that the trailer compresses as it reverses in, while a dock shelter is a frame with curtains or cushions that closes around the trailer without being crushed by it. Both reduce the draughts, weather and heat or cold that pass through the gap between trailer and building.
- Dock seals press against the rear and sides of the trailer body. Guide price £1,100–£2,600 per set, ex VAT.
- Retractable dock shelters use side and head curtains on a sprung or flexible frame. Guide price £1,900–£4,400 per shelter, ex VAT.
- Inflatable dock shelters use air-filled cushions that inflate once the trailer is docked. Guide price £6,800–£12,800 per shelter, ex VAT.
The choice affects how well the bay holds temperature, how much of the trailer opening is usable and how much maintenance you face. Size, fabric, head curtain depth and, for inflatables, the fan and controls move the price within each range.
How do foam dock seals work?
Foam dock seals work by compression: the trailer reverses into foam pads fixed to the building, and the pads squeeze against the back of the trailer to close the gap. The result is a tight closure, which makes seals a strong option for temperature-controlled loading where the fleet is consistent.
Seals have limits worth knowing:
- They suit a fleet of similar vehicles. A pad set sized for one trailer may leave gaps on a narrower vehicle or be overloaded by a wider one.
- The pads sit against the trailer's rear frame and can project slightly into the opening, narrowing access at the edges.
- Every docking compresses the pads, so the cover fabric wears with use, especially when trailers dock off-centre or too hard.
- Bumper projection has to be set so the pads compress enough to seal but are not crushed.
Seals are a good fit for dedicated fleets and chilled goods where the vehicle type rarely changes.
How do retractable and inflatable dock shelters differ?
Retractable shelters use fixed curtains on a frame that flexes as the trailer reverses in, while inflatable shelters use cushions that stay deflated until the trailer is in position and then inflate around it. Both leave the full trailer opening clear for loading.
Retractable shelters have side and head curtains that drape over the trailer body. The sprung frame gives way if a trailer clips it and returns to shape. They accept a wide range of trailer widths and heights and are the lower-cost shelter option. The closure is less tight than a seal or an inflatable, so some air still moves at the curtain edges.
Inflatable shelters have a fan that inflates side and head cushions once the trailer is docked, pressing them against the trailer body. Because the cushions are deflated while the trailer reverses in, there is less contact during docking. They give a close seal across mixed fleets, which suits chilled and frozen operations, but they cost more, and the fan, airbags and controls need regular checks.
How does fleet mix affect the choice?
Fleet mix is often the deciding factor: seals suit a consistent fleet, while shelters cope better with vehicles of different widths and heights. Before choosing, list every vehicle type that uses the bay, including occasional deliveries.
- One trailer type, same dimensions. Seals can be sized precisely and give a tight closure.
- Mixed articulated trailers, curtain-siders and refrigerated units. A retractable or inflatable shelter adapts to the differences.
- Double-deck trailers or container chassis. Check the height of the head curtain or head pad so tall vehicles are covered without striking the frame.
- Rigid lorries and vans. Small vehicles may not reach seals or curtains set for trailers, so a separate bay may work better.
If one bay serves several customers or hauliers, assume the fleet will change over time and lean towards a shelter. A shelter or seal that matches today's vehicles but not next year's will leak air and wear quickly.
What is the trailer door hinge gap and why does it matter?
The hinge gap is the space between the trailer body and its rear doors when they are swung open, and it is a common point for air to leak at a dock. Trailers with swing doors normally have them opened and folded back before reversing in, which leaves a vertical gap at each hinge line.
Shelters and seals handle it differently:
- Foam seals press against the rear frame of the trailer. With the doors folded back, the hinges and door edges sit close to the pads and can tear the cover if the trailer docks off-centre.
- Retractable shelter side curtains need enough depth to reach over the open doors and close the hinge gap.
- Inflatable shelter side cushions inflate against the trailer body and doors, filling the gap more closely.
At survey we check the hinge positions and door arrangements of the vehicles you handle, so the shelter or seal is sized for them rather than for an average trailer. Trailers with roller rear doors avoid the hinge gap but need enough headroom inside the shelter or seal for the door to open.
Which option is best for temperature control?
For chilled, frozen or heated buildings, a seal or an inflatable shelter generally gives the closest fit around the trailer, while a retractable shelter gives general weather protection with more air movement at the edges. The mechanism is simple: any gap around a docked trailer lets heated or chilled air escape and outside air in.
To keep temperature loss down at the bay:
- match the shelter or seal to the vehicles so gaps are small
- use an insulated or cold store dock door and close it whenever no trailer is docked
- seal the leveller edges in cold stores
- repair torn curtains and flattened pads promptly, as damaged covers stop sealing
In ambient warehouses the priority is usually keeping rain, wind and debris out of the dock, which a retractable shelter does well at a lower cost.
We do not quote energy savings as figures, because they depend on the building, the temperature difference and how long doors stay open.
What size of dock shelter or seal do I need?
The shelter or seal must be sized to the door opening and to the range of vehicles that use the bay, with the head curtain or head pad set for the tallest vehicle and the sides set for the widest. Getting this wrong leaves gaps or causes damage.
At survey we measure and check:
- the door opening width and height, typically about 3.0 m by 3.0 to 3.5 m
- the tallest and lowest trailer roofs you receive
- trailer widths and rear door arrangements
- the projection of the dock bumpers, which sets how far the trailer stops from the wall
- the wall above and beside the opening, to confirm it can carry the frame
Shelters are generally wider and taller than the opening so the curtains or cushions can reach the trailer body. Seals are sized more tightly to the vehicle, which is why they work best when the fleet is consistent.
What damages dock shelters and seals?
Damage commonly comes from trailers docking off-centre, at an angle or too hard, which tears curtains, splits pad covers and bends frames. Weather, sunlight and age also wear fabrics over time.
- Dock bumpers stop the trailer at the right distance so seals are compressed but not crushed. See dock bumpers.
- Wheel guides and markings centre the trailer on the bay.
- Retractable frames flex when clipped, which limits damage compared with a rigid frame.
- Inflatable cushions sit clear of the trailer until inflated, but punctures, fan faults and control problems need prompt repair.
Replacement curtains, pads, airbags and frames are handled through dock shelter and seal repairs. Repairs are chargeable, with the price agreed before anyone attends. Including shelters and seals in routine servicing means small tears are found and repaired before they spread.
Which should I choose: a dock shelter or a dock seal?
Choose a seal for a consistent fleet and tight temperature control on a budget, a retractable shelter for mixed fleets and general use, and an inflatable shelter for mixed fleets where temperature control matters most. Use this as a starting point:
- Consistent fleet, chilled goods, tighter budget: foam dock seals.
- Mixed fleet, ambient goods, general weather protection: retractable dock shelter.
- Mixed fleet, chilled or frozen goods: inflatable dock shelter.
- Full trailer width needed for wide loads: a shelter rather than a seal.
- Frequent hard or off-centre docking: retractable shelter, plus wheel guides and bumpers.
- Tall vehicles such as double-decks: a shelter or seal with a head curtain or pad set for the tallest vehicle.
We confirm the choice at a free site survey, after measuring the opening and checking the vehicles that use it.
Questions
Are dock seals or dock shelters better for cold stores?
Both can work. Foam seals give a tight closure when the fleet is consistent, and inflatable shelters give a close seal across a mix of trailer sizes. Retractable shelters are better suited to general weather protection, as some air moves at the curtain edges. Whichever you choose, pair it with an insulated cold store door and sealed leveller edges.
How much do dock shelters and seals cost?
Guide prices for supply and fit, excluding VAT, are £1,100–£2,600 per set for foam dock seals, £1,900–£4,400 for a retractable dock shelter and £6,800–£12,800 for an inflatable dock shelter. Size, fabric, head curtain depth, the frame and the fan and controls for inflatables move the price. The written quote after survey is the fixed price.
Can a dock shelter be fitted to an existing loading bay?
Yes, in most cases. Shelters and seals fix to the outside wall around the door opening, so they can usually be added or replaced without changing the door or leveller. At survey we check the wall construction, the opening size, the bumper projection and the vehicles using the bay, because those decide the size and type of shelter or seal that will fit.
Why do dock seal covers wear out?
Every docking compresses the pads, and trailers that arrive off-centre, at an angle or too hard scuff and tear the covers. Hinges and door edges can also catch the fabric. Worn covers stop sealing properly, letting air and weather through. Wheel guides, correctly set bumpers and good driver practice slow the wear, and covers or pads can be replaced as a chargeable repair.