Rigid boards for outdoor signs
Time outdoors is the question that settles this. Tell us whether the sign has to last a fortnight, a season or indefinitely, and most of the choice is made.
Pick by how long it stays out.
| Time outside | Usual choice | Why |
|---|---|---|
| Days or weeks | Corex | Waterproof, light and low in cost |
| A season, on a sheltered wall | 5mm Foamex | Smoother face and neater look than Corex |
| A season, somewhere exposed | 3mm Dibond | Stays flat in sun and wind |
| Long term, or at a permanent site | 3mm Dibond | Will not soak up water, swell or sag |
Two boards drop out straight away. Polyboard has a paper face and will warp when it gets damp. MDF swells. Neither should go outside.
Sun does as much damage as rain
People worry about rain, but direct sun is often the harder test. Dark artwork on a south-facing wall gets hot, and plastic sheet expands as it warms. If a Foamex sign is screwed down tightly at every corner, it has nowhere to go and it can ripple. Leave the holes a little larger than the screws, and do not overtighten. Stiffer aluminium composite is less affected, which is why it is the board for long stays.
The board is only half of a weatherproof sign
A rigid backing does not protect the image. Outdoors, the face should be a printed vinyl, not paper, and a protective finish helps against scratches and weather. Ask us what suits your site. Our page on weatherproof signs looks at the whole sign, and laminate or seal explains the surface options.
Wind and what is behind the sign
A board is a flat plate, so wind pushes hard on it. Fix a sign to something solid, and use more fixings on larger panels. Brickwork, timber cladding and fencing all need different fixings. Fence panels and thin posts may flex and work a board loose, so check them before you pick the size. If the sign is big or close to a public path, get someone competent to look at the fixing.
Prices for the main three
| Board | A1 | A0 | 40in x 30in | 60in x 40in |
|---|---|---|---|---|
| Corex | £10 | £20 | £15 | £30 |
| 5mm Foamex | £14 | £25 | £22 | £37.50 |
| 3mm Dibond | £24 | £35 | £30 | £55 |
Guide prices from our price list. They exclude VAT and delivery and assume print-ready artwork.
Before you put it up
- Some outdoor signs need advertisement consent. Your local planning authority can tell you what applies.
- If you rent the building, ask the landlord before you drill.
- In a conservation area, or on a listed building, expect tighter rules, and check before you order.
- Think about graffiti and theft on low signs in quiet spots: a lower-cost board may make more sense there.
Print out in the weather.
Your questions.
Can 3mm Foamex go outside?
It can for short jobs, but it is thin and moves with heat. If you have chosen Foamex for outdoor use, 5mm holds its shape better on a larger sign.
Do outdoor boards need to be sealed?
It is a good idea for anything staying out beyond a short event, particularly in reach of people. Ask us what suits the print you have chosen.
Can a sign be mounted on a post?
Yes, as long as the post is suitable, but we would need to know how it is fixed. Send a photo of the location and we will advise on what to plan for.