Short answer: yes, and it usually looks excellent, because steel framed units have the ceiling height and open span that a hexagon grid suits.
The complications are all in the fixing. You cannot treat a profiled steel roof like a plasterboard ceiling, and the most common mistake creates a leak that does not show up until the first proper downpour.
The one rule: never fix into the roof sheet
This is the mistake to avoid above everything else.
Profiled steel roof sheeting is a weather skin, not a structural element. Drill a hole in it to hang something and you have made a penetration in the only thing keeping water out. Even sealed, the hole sits under load from a hanging fitting, the sheet flexes with temperature, and the seal fails. You will find out in about eight months.
Everything hangs from the steelwork, not from the sheet.
Where the fixings actually go
Purlins
The horizontal steel members running across the building between the main frames. These are what the roof sheet is fixed to, and they are the natural mounting point for lighting.
Purlins are usually at fixed centres, often somewhere between 1.2m and 1.8m apart depending on the building. That spacing is a genuine design constraint, because it determines where you can fix without adding secondary steel.
Beam clamps and girder clips
Usually the best answer. These grip the flange of a purlin or beam mechanically with no drilling at all.
Two big advantages. First, no holes in anything, so no corrosion risk and no compromised coating. Second, if you are leasing the unit, a clamped installation is far easier to remove at the end of the term, and many leases prohibit drilling the structure anyway. Check yours before you buy anything.
Unistrut or channel spanning purlins
If your grid does not conveniently line up with purlin positions, run channel across two or more purlins and hang the lighting from that. This gives you continuous freedom to position panels wherever the layout wants them rather than wherever the steel happens to be.
For any grid of reasonable size in a commercial unit, this is usually how it gets done properly.
Self drilling screws into purlins
Acceptable where the purlin is accessible and the load is light, using fixings rated for the job. Less ideal than clamps because you are penetrating coated steel, which introduces a corrosion point in a building that already has a condensation problem.
What not to use
- Magnets. Fine for a temporary work light, not for a permanent ceiling installation at height.
- Adhesive fixings. Steel roofs swing through a wide temperature range and adhesives creep.
- Anything fixed to the sheet alone. Covered above, but worth repeating.
Height, and why you almost certainly need suspension
Steel framed units are tall. Eaves heights of 4m to 6m are normal, and the underside of the roof can be higher still at the apex.
Light falls off with distance. A grid mounted tight to a 5m roof produces a fraction of the useful light at working height that the same grid would at 2.4m. People try to solve this by buying more panels, which is the expensive answer.
The cheap answer is to drop the grid. A suspension kit brings the lighting down to a sensible working height, typically somewhere between 2.5m and 3.5m depending on what needs to pass underneath. Suspending from purlins with wire or chain is standard practice in industrial lighting.
Check your clearances first. Vehicle heights, any lift, any crane or gantry, and the arc of the roller shutter all dictate how low you can go.
Condensation, and why IP rating matters here
Uninsulated steel buildings sweat. The roof sheet drops below dew point overnight, moisture condenses on the underside, and it drips. Anyone who has worked in one in February knows exactly what this looks like.
Three consequences for lighting.
- Pick an appropriate IP rating. IP20 fittings under a sweating roof are a poor idea. Splash resistance at minimum.
- Do not put the driver where drips land. Mount it somewhere sheltered and ventilated, ideally on a wall rather than up in the roof space.
- Expect earth leakage problems if moisture gets in. This is a common cause of RCD tripping in metal buildings.
If the building is insulated, or has an anti condensation coating or membrane on the underside of the sheet, most of this goes away. If not, factor it in.
Cabling in a metal building
- Run cables in trunking or conduit rather than loose. Cut steel sheet edges are genuinely sharp and will damage insulation over time.
- Use grommets anywhere a cable passes through steel.
- Leave slack. Steel buildings move with temperature far more than masonry ones, and a taut cable run in July is a tight one in January.
- Support cables at proper intervals rather than letting them hang.
- Earthing and bonding of the structure is an electrician's decision, not a DIY one. Metal framed buildings have specific requirements.
Designing the layout around the steel
In a plasterboard garage you decide the layout and then find fixings. In a steel building it works the other way round, at least partly.
Measure your purlin centres first, then design the grid to suit. Hexagons are more forgiving here than square panels because a honeycomb can be stepped and offset without looking wrong, but you still want your suspension points landing on steel rather than in mid air.
If the layout you want fights the structure, span the purlins with channel and stop fighting it.
Frequently asked questions
Can I fit hexagon lighting in a leased industrial unit?
Usually yes, but check the lease for restrictions on drilling the structure and for reinstatement obligations at the end of the term. Clamped fixings are often the acceptable route.
How high should I hang lighting in a steel workshop?
Low enough to be effective and high enough to clear everything that moves underneath. Somewhere between 2.5m and 3.5m suits most workshops, subject to vehicle and equipment clearances.
Will condensation damage LED panels?
It can, if the IP rating is not suited to the conditions. Water reaching a driver or a connection is the usual failure, not the panels themselves.
Do I need an electrician?
For a plug in kit connected to an existing socket, not necessarily. For a hardwired installation in a commercial premises, yes, and you will want the certification for insurance regardless.
Send us your purlin spacing and eaves height through our contact page and we will suggest a layout, or browse the hexagon lighting range and suspension accessories.