Loading Bays and Docks in a New Warehouse: Plan the Vehicle Flow Before the Slab Is Poured

Ask a warehouse owner what slowed the building down after move-in and the answer is rarely the roof or the racking. It is the doors. Lorries queue on the apron because there is nowhere to wait, the bay that was meant for the big vehicle only suits the small one, or a forklift has to cross a joint in the slab every time it goes out. On our commercial warehouse construction page we put it in one sentence: getting the loading bays wrong slows every inbound and outbound move for the life of the building.

This is about the loading-bay decisions that have to be made on paper, before the slab is poured and the frame is ordered, because they are the ones you cannot undo cheaply afterwards. The question behind it is the one owners actually type: how do I plan loading bays and docks for a new warehouse in Singapore?

Start with the vehicles, not the doors

A loading bay is not a door. It is a door, the apron outside it, the space a vehicle needs to get onto that apron and the space your forklifts need inside to pick up from it. The number of doors is the last thing to settle, not the first.

The first thing is a plain list of the vehicles that will actually arrive, written down by whoever runs your inbound and outbound:

• Which vehicles. Vans, small lorries, larger lorries, trailers, containers on a trailer. Each sits at a different height and needs a different amount of room to turn and reverse.
• How many at once. The busiest hour, not the average day. One vehicle loading while two wait is a different building from one vehicle at a time.
• How they load. From the back or from the side, by forklift or by hand, pallets or loose cartons. A bay planned for pallets on a forklift is the wrong bay for a hand-loaded van.
• Whether the mix will change. If a bigger vehicle type is likely within a few years, say so now. A bay is designed around the vehicle it was drawn for.

We plan dock levellers, loading-bay height and position, and the apron and turning space against your real vehicle flow, not a generic layout. That matters because a dock that suits a small lorry and not a larger one cannot be fixed by good management, only by cutting into the building.

The apron decides how the bay works

Most of the trouble sits outside the building. An owner looks at the floor plan, sees four doors and thinks four vehicles can load at once. They can only if there is space in front of each door for a vehicle to arrive, line up and leave without blocking its neighbour.

Walk through it as a vehicle would. Where does it enter the plot? Where does it turn? Does it reverse in, and if so in a straight line or across the path of the next one? Where does the driver wait if the bay is busy — on your apron or on the public road? If the answer to the last question is the road, you have a building that works only when the bays are empty.

This is why the site matters before the building does. The plot and its access govern how much apron you can give the doors, and we list the site constraints as one of the four things we establish before we quote. If the plot is tight, the honest answer may be fewer doors with better space in front of them, rather than more doors that cannot all be used.

Dock height or ground level: decide by what comes through the door

The choice between a raised dock and a ground-level door follows the vehicles and the loads, not fashion.

• A raised dock with a dock leveller lets a forklift drive straight from the floor onto the bed of a lorry whose floor sits at roughly dock height. It is the usual answer for pallet traffic from the same type of vehicle all day.
• A ground-level door suits vehicles that load from the ground, mixed fleets and loads that are not palletised.
• Where both kinds of vehicle arrive, you may need both kinds of door, and that has to be in the brief, because it changes the slab around each one.

The part owners miss is that a dock leveller sits in the floor. It is built into the slab and the structure around the opening, so its position is set when the slab is designed, not when the equipment is bought. A dock bought later has to go where the slab already allows it.

Where the doors sit against the frame and the racking

Three layouts have to agree, and they are usually drawn by three different people: the frame, the racking and the doors.

The column grid sets where the structure can and cannot be opened. A column cannot stand in a door opening, so the doors have to fall between columns, or the grid has to be arranged around them. The racking layout sets where the aisles run, and the best door position is usually the one in line with an aisle, so a forklift comes off the racking and goes straight out rather than turning in a tight space. And the floor slab around the doors has to carry a loaded forklift going in and out of the same place hundreds of times, which is the hardest work the floor does.

If the three are only reconciled after the frame is ordered, someone is going to move something. Moving a door after the structure is set means cutting an opening into a finished wall. That is why, in our design-and-build brief, the door and dock positions are one of the four sign-off points we fix before the design freezes: checked against the vehicles that will really use them.

Inside the door: the space a forklift needs

A bay needs staging room behind it. Pallets coming off a vehicle have to land somewhere before they go to the racking, and pallets going out have to be gathered somewhere before they go on. If the first row of racking starts at the door, there is no staging area and the aisle becomes the staging area, which means every move through that door blocks the next.

Ask for the staging depth to be drawn on the floor plan as its own rectangle, behind each door, and kept free of racking in the drawing. If that costs you a bay of racking, it is cheaper than a warehouse where the forklifts cannot get past each other.

Rain, shelter and the Singapore factor

Goods that are loaded in a downpour get wet, and the floor at the door turns slippery. Whether the bay needs a canopy or an overhang, and how far it should reach beyond the door, depends on what you store and how it is packed. Water-sensitive goods make it a requirement; durable goods may make it a convenience. Either way it is a structural item, because a canopy hangs off the frame or stands on its own columns, and that has to be in the design from the start. Adding it later means adding structure to a building that was not designed for it.

Surface water also has to go somewhere. Slab falls and drainage at the doors should be part of the slab design, so that water runs away from the building rather than into it when a vehicle opens the door. Ask whoever is designing the slab to say how the area outside the doors drains.

What to put in writing before the quotes come back

If you are comparing quotations, loading bays are one of the easiest places for two bidders to describe two different buildings, because the brief rarely says enough. Give every bidder the same one-page answer to these:

1. The vehicle types, and the most that will be at the bays at once.
2. How the goods are loaded — by forklift, by hand, pallets or loose.
3. Dock-height doors, ground-level doors, or both, and how many of each.
4. Whether the vehicle mix may change, and to what.
5. Where vehicles will wait, and where your plot allows them to turn.
6. Whether the bays need cover from the rain.

Then ask each bidder to draw the apron and the turning path against your plot, not just mark door positions on the elevation. A bidder who has drawn the vehicle path has thought about the bay. A bidder who has only put four door symbols on a wall has not, and the price will not include what that costs to put right later.

If the building already exists

Everything above is about a new build, where the doors are still lines on paper. If you already have a unit or a shed, the sequence changes: you are working around fixed door positions and a slab that is already poured. Before spending on a bigger building, read how to get more out of the shed you already have. For the frame side of the same conversation — what the steel package covers once the layout is settled — see the steel package in a warehouse build.

The short version

• A loading bay is a door, an apron, a turning path and staging room, not just a door.
• Start from the vehicles you will really have, how many at once, and how they load.
• Give the apron as much thought as the doors; if vehicles wait on the road, the bays only work when they are empty.
• Choose dock-height or ground-level doors by what comes through them, and remember a dock leveller is built into the slab, so its position is set early.
• Reconcile the column grid, the racking layout and the door positions before the frame is ordered.
• Draw the staging area behind each door.
• Ask every bidder to draw the apron and turning path, not just mark doors on an elevation.

If you are planning a warehouse and want the loading bays looked at before the layout is fixed, WhatsApp us on 9107 2601. Send us the vehicles, the plot and how the goods move, and we will tell you what the layout is missing. Wong Lye Pte Ltd holds a BCA General Builder Class 2 (GB2) licence and builds commercial warehouses in Singapore, with the BCA structural submissions handled as part of the build. Commercial and industrial work is where Wong Lye began: over 1,500 commercial and industrial clients since 2014, building warehouses, before we ever took on a landed home. See commercial warehouse construction.