Structural racking
Built for the aislesthat get hit
Hot-rolled sections, bolted rather than hooked. It costs more per bay and it is the wrong answer for most of a warehouse — but there are five rooms where it is the only one, and this page is about telling them apart. OTS designs it, supplies it, installs it and certifies it.
The cases
Five rooms that ask for it
CSA A344 keeps a short list of applications that need a special study before racking is specified. Most of this page is that list, read as a buying decision rather than as a clause.
- Heavy or concentrated unit loads
- Coil, casting, block, batteries, drum, stone — anything that arrives dense. The minimum capacity of a component is the sum of the maximum weight of everything it supports, with no reduction for average weights or fill factors. A bay is sized on the heaviest pallet that will ever sit in it, and that arithmetic is where a heavier section starts paying.
- Lanes the truck drives into
- In drive-in and drive-thru the truck enters the structure carrying a raised load. Contact is the operating mode rather than an accident, and column guards inside the lanes have to be anchored to the floor. No layout asks the joint question more often.
- Cold, wet and washed down
- Freezer and chill rooms, and food processing that hoses the floor at end of shift. Applications needing special sanitary provisions are on the standard's special-study list in their own right — and where the air is corrosive the standard stops recommending and starts requiring.
- Racking the public walks past
- Retail where customers are present raises the consequence of any failure, so the damage limits the engineer sets have to account for it. The standard adds a practical note for these areas: it may be advisable to bolt the lower beam levels, to discourage anyone lifting one out.
- Outdoors, or on a surface that is not level
- Racking installed outside a building, where the surface may not be level or may not give enough support and where wind and snow become forces on the structure, is on the same list. A calculation before it is a finish.
Notice what is not on that list: an ordinary dry, heated building with the truck staying in the aisle. That is most of Québec's warehousing, and there Roll-Formed Racking is the right answer, at less steel per bay. Paying for structural where the operation will never call on it is not caution — it is money that does not come back.
In a corrosive environment, galvanizing is not an upgrade.
CSA A344 is written almost entirely as recommendations. Here it changes register: racking installed in corrosive environments must be protected by galvanizing, to preserve its service life and its structural integrity. That holds for either family of steel, and it is settled when the rack is specified — not after the first inspection report explains why the columns look like that.
Ordered with the steel
Half of rack protection is the frame
The standard lists eight measures commonly used to protect racking from damage. Most of them are not accessories — they are decisions taken while the frames are still a drawing, which is where a structural conversation usually starts.
- Cant-leg frames — the aisle-side foot of the frame is cut back and replaced with structural steel, clearing floor space in front of the aisle so trucks have room to manoeuvre
- Doubled columns, usually the front columns only, up to the second horizontal brace or the first beam level
- A heavy bottom horizontal brace, its section width matched to the columns
- A heavy bottom diagonal brace
- More anchors, or larger ones
- Column guards, fitted at the factory or ordered separately
- Row-end protectors where the aisles open
- Mechanical rail guidance for the trucks, or electronically guided handling equipment
Which of the eight you need is not a taste question, and it is not answered here. It is answered by where the damage is actually landing in your building and at what height — a guard fitted where the impacts are not is decoration. Protection goes through that properly.
The other side of it
A bolt is a maintenance item
Structural buys you a joint that does not depend on a hook staying seated. It also buys you a joint with a specification, and a specification is somebody's job.
- Tightening is specified, and inspected
- Where beams connect to columns with bolts, the installation requirements — including any inspection and tightening requirements — should be stated in the document that establishes the rack's capacity. Ask for them at handover. A bolted rack whose tightening requirements live nowhere is a bolted rack nobody can verify.
- Bolts and nuts are not reused
- Not unless the manufacturer's specification specifically allows it. The clause matters most on the day it is least convenient — a member coming out for repair, with the aisle closed and a crew standing in it.
- A damaged member comes out
- A damaged component may be replaced by an equivalent structural member, provided the engineer certifies the resulting structure. What is not acceptable is certifying a repair kit or individual components in isolation: how the piece integrates into the frame it went into has to be fully accounted for.
- The rating still moves with the geometry
- Bolted does not mean fixed. Moving beams or reconfiguring a run needs an engineer's approval or certified documents first and re-certification of the structure after — the same clause that governs the cold-formed rack in the next aisle. Relocating a run is certified as a new installation.
The heavier section does not buy an easier file, either. Structural racking is inspected on the same cycle and graded against the same categories as everything else in the building — Inspection covers what that involves.
FAQ
Questions we get
Not as a family. What a bay carries is set by the section shape, the width, the gauge, the properties of the steel, the forming process and where the beam attaches — a designer can reach a given load with either. The honest difference is what happens around the load: a bolted joint in a hot-rolled section behaves differently under contact than a connector hooked into a thin-wall cold-formed column. Buy it for the aisle, not for the adjective.
It is one of the places it is most often specified, and two things get settled at design rather than on site. Racking in a corrosive environment must be protected by galvanizing, to preserve its service life and its structural integrity. And applications needing special sanitary provisions — food processing among them — call for a special study before the racking is specified. Neither is a finish you add afterwards.
Treat it as no until an engineer says otherwise. The two families are told apart by section shape, width, gauge, steel properties, forming process and where the beam attaches — and that last one is exactly what would have to match. Wherever mixed or used components are involved, each has to be examined by a competent person, anything of doubtful compatibility set aside, and the capacities determined before anything is loaded.
Usually yes, and the reasoning does not change with the steel. All rack damage reduces a structure's real capacity, and damage that keeps returning to the base of the same columns is the standard's own signal that guards, or a change to the layout or to operating practices, are needed. What structural gives you is more ways to answer that inside the frame — doubled columns, a cant-leg frame, a heavier bottom brace.
Related
Next step
Describe the aisle before the rack
Book a call with an advisor. The loads, the trucks, the temperature and the traffic decide whether this page is about your building — and one conversation settles it.