Both of our heavy duty shelving ranges are rated by the weight each shelf can carry: 175kg per shelf on the five-tier RISI175 units, and 400kg per shelf on the four-tier heavy duty units. That one number decides most of what follows, so this guide explains what the rating means, what each range is actually built from, and which one suits the things you are storing. If you already know your answer, go straight to 175kg five-tier shelving or 400kg heavy duty shelving; the full range is on the heavy duty shelving page.
What "kg per shelf" actually means
The rating is the maximum load for one shelf level, with the weight spread evenly across the board. It is not a rating for a single heavy item dropped in the middle. A 175kg shelf carrying 175kg of boxes spread edge to edge is working as designed; the same shelf carrying one 150kg engine block in the centre is not, because the board and the beams under it are taking the whole load in one place.
Two practical rules follow from that:
- Put the heaviest items on the lowest shelves and spread them out.
- Work out the load per shelf, not per bay. A five-tier RISI175 bay has a total of 5 × 175kg = 875kg across its shelves; a four-tier 400kg bay totals up to 1600kg. Neither figure means you can put that much on one level.
The two ranges side by side
| RISI175 five-tier shelving | 400kg heavy duty shelving | |
|---|---|---|
| Load per shelf | 175kg, evenly distributed | 400kg, evenly distributed |
| Shelf levels | 5 | 4 |
| Size (H × W × D) | 1800 × 900 × 400mm | 1830mm high; 1200 or 1800mm wide; 450 or 600mm deep |
| Frame | 0.5mm powder-coated steel, boltless | 1.5mm powder-coated steel, boltless |
| Shelf boards | 3.3mm MDF with a centre support bar under every shelf | 15mm chipboard with shelf support bars |
| Colours | Blue and orange, or black and yellow | Blue and orange |
| Buying options | Single bay, or 3, 5 and 10-bay deals | Single bay in four sizes, or a 3-bay deal |
When 175kg per shelf is enough
For most garages, home workshops, stockrooms and offices, 175kg per shelf is more than the shelf will ever see. Realistic loads on a single 900mm-wide shelf look like this:
- Four or five storage totes of paperwork, seasonal kit or camping gear: roughly 60–100kg.
- A row of paint tins, adhesives and cleaning products: well under 50kg.
- Hand tools, a cordless tool kit and their cases: 20–40kg.
- Cartons of retail stock or archive boxes: typically 8–15kg each, so eight boxes is around 100kg.
Because RISI175 gives you five levels in a 1800mm-high bay, it is also the better choice when you want to store a large number of lighter items and keep everything visible. The blue and orange five-tier shelving unit is the single bay; the 3-bay RISI175 deal, and the 5 and 10-bay deals, bring the price per bay down when you are lining a whole wall. Browse the complete RISI175 range for both colourways.
When 400kg per shelf is the right choice
Step up to the 400kg range when the load is genuinely heavy, dense or awkward, or when the shelving is going into a working environment where it will be loaded and unloaded every day:
- Car and van parts: brake discs, batteries, alloy wheels, gearbox and engine components.
- Boxed stock in a warehouse or stockroom that is picked from constantly.
- Bulk fluids, bags of material, tiles, fixings in trade quantities.
- Workshop machinery, compressors, welders and heavy power tools.
- Tyres, which are bulky as well as heavy and need the 600mm-deep boards.
The frame is three times the steel gauge of the RISI175 (1.5mm against 0.5mm) and the shelf boards are 15mm chipboard rather than 3.3mm MDF, which is where the rating comes from. The trade-off is four shelf levels rather than five, and a bigger footprint. The compact option is the 1200 × 450mm 400kg unit; the largest is the 1800 × 600mm 400kg unit, and there is a 400kg 3-bay deal in every size. See the whole 400kg heavy duty shelving range.
Space and cost: the trade-off
The two ranges overlap in price more than people expect, because a single 400kg bay is not much dearer than a single RISI175 bay once you factor in what it holds. Where they separate is quantity and footprint.
- Footprint. A RISI175 bay is 900mm wide and 400mm deep. The smallest 400kg bay is 1200mm wide and 450mm deep; the largest is 1800 × 600mm. Measure the wall first: three RISI175 bays fill 2700mm, two 1200mm 400kg bays fill 2400mm, and one 1800mm 400kg bay fills 1800mm.
- Cost per shelf level. A 10-bay RISI175 deal gives you 50 shelf levels for less than the price of three 400kg bays. If the load is light, that is a lot more storage for the money.
- Cost per kilogram. If the load is heavy, one 400kg shelf does the work of two-and-a-bit RISI175 shelves, and a 400kg bay's 1600kg total is nearly double a RISI175 bay's 875kg.
- Depth. Only the 400kg range offers 600mm-deep boards. If what you store is deep (tyres, large totes, tool chests), that decides it on its own.
A quick way to decide
- List the heaviest things going on one shelf and add them up. Under about 120kg per shelf with room to spare: RISI175. Over that, or one item over 50kg: 400kg.
- Measure the depth of the largest item. Over 400mm: 400kg range (450 or 600mm deep).
- Measure the wall and pick widths that fill it without a gap: 900mm (RISI175) or 1200/1800mm (400kg).
- Buy bays as a deal if you need three or more of the same size: the 3, 5 and 10-bay RISI175 deals and the 400kg 3-bay deal are priced per bay below the single-bay price.
Still unsure, or fitting out a whole unit? The team quotes mixed runs of both ranges every week: get a trade quote.
Frequently asked questions
Can I mix 175kg and 400kg bays in one run?
They are different frame sizes and do not clip into each other, so they stand side by side as separate units rather than sharing uprights. Many workshops do exactly that: 400kg bays along the wall where the heavy kit lives, RISI175 for everything else.
Does the load rating drop if I move the shelves?
No. Both ranges are boltless, and the shelf positions are adjustable on the uprights. The rating applies to each shelf wherever it sits, provided the load is evenly distributed.
Are the ratings per shelf or for the whole bay?
Per shelf. The bay totals quoted on the product pages (875kg for RISI175, 1600kg for a 400kg bay) are simply the shelf rating multiplied by the number of shelves.
Do I need to fix the shelving to the wall?
Both ranges are free-standing. Fixing to the wall is good practice for any tall shelving in a busy area or where children are present, and is worth doing on 1800mm-plus units that will be heavily loaded on the top shelf.
Which range comes flat-packed?
Both. RISI175 is supplied in one carton per bay with an English assembly manual and protective caps; the 400kg units are boltless and assemble the same way, with shelf support bars and plastic foot mounts included.
Ready to choose? Start with 175kg five-tier shelving for everyday loads or 400kg heavy duty shelving for the heavy stuff, or compare everything on the heavy duty shelving page.