Our own facade sign: 16 magnets instead of drilling
When we moved to Nuenen, we got a new illuminated facade sign. We did not screw it on, but hung it with 16 rubber pot magnets of Ø88 mm. Why so many? We explain it here.
When we moved to our new premises on the Spegelt in Nuenen, it came with a new facade sign: a panel of 2.25 by 0.65 metres, with our logo and name in backlit channel letters. The facade is made of steel cladding. For a magnet specialist the question was obvious: why drill, if it can also be done magnetically?
The sign was made by Geert-Jan Worst of Worst Reclame from Den Hoorn, who has been ordering magnets from us for his sign projects for years. It was mounted by our own colleague Marcel. Fixed with 16 rubber pot magnets of Ø88 mm with M8 threaded stud.
Why magnetic?
- No holes in the facade. The cladding stays intact and watertight, without rust-prone drill holes.
- No scratches. The rubber coating protects the finish of the facade panels.
- Quick to mount and align. The sign can be shifted until it hangs perfectly straight.
- Easy to move or replace later. Handy for a new corporate identity or a move.
Why 16 magnets, and not 4?
A rubber pot magnet of Ø88 mm has a holding force of approx. 55 kg. Four magnets together are over 200 kg, plenty for a sign of a few dozen kilos, you would think. In practice it works differently, which is why we deliberately chose more magnets.
1. Sideways force
The stated holding force applies when you pull the magnet straight off a thick, flat steel plate. A sign on a vertical facade, however, pulls downwards, along the steel. A magnet then slides away at about 15 to 20% of its holding force. Rubber adds grip, but to be safe count on about 10 kg per magnet. Read more about the difference between holding force, pull force and working load.
2. Thin, profiled facade sheet
Facade cladding is thin steel with ribs. A magnet has less contact surface and less steel to grip than on a thick plate. That also reduces the holding force considerably.
3. Wind
This is the most often forgotten. In a strong storm, a sign of almost 1.5 m² catches wind that can pull it straight off the facade, easily tens to over a hundred kilos. That comes on top of the weight of the sign and the lighting.
The calculation
| 4 magnets | 16 magnets | |
|---|---|---|
| Holding force on paper | approx. 220 kg | approx. 880 kg |
| Sideways (approx. 10 kg per magnet) | approx. 40 kg | approx. 160 kg |
| Reserve for wind and thin facade sheet | tight | ample |
With four magnets the sign would probably stay up in calm weather, but in a storm the margin is too small. With sixteen magnets you spread the weight and wind force over many more points, and you have ample reserve. For a facade mounting, choose too many magnets rather than too few.
Tips for your own facade sign
- Choose a pot magnet with rubber coating. It grips on a vertical wall and protects the facade. With an M8 threaded stud you easily fix it to the frame or the back of the sign.
- Spread the magnets evenly across the back, including along the edges, so the wind gets no grip anywhere.
- Check the surface. Does a magnet work on the facade? Test it first. A magnet does not stick to aluminium or most types of stainless steel. See is stainless steel magnetic?
- Above walkways, always use an extra safety, for example a thin steel cable. Magnets are an excellent fixing, but the holding force is not a permitted working load.
- Unsure about the number? Calculate it with the Magnet Advisor, or contact us. We are happy to help.
Want to know more about signs on facades? Also read magnetic mounting of facade signs. Are you a sign maker or do you regularly mount signs, like Worst Reclame? Then see our business options, with volume discount and ordering on account.
