House Sign Materials Compared: Slate, Acrylic, Wood and Metal

The short version: slate and stone suit period properties and weather beautifully but are heavy and brittle. Acrylic is light, colour-fast and completely weatherproof, and works best on modern frontages. Hardwood brings warmth to brick but only certain species survive outdoors untreated. Metal is durable and expensive, and some finishes weather more than buyers expect. Contrast and fixing method matter more than the material itself.

Material is usually the first thing people choose and the last thing they research. This is an honest comparison of the five materials you will actually encounter when shopping for a UK house sign — including the ones we do not make.

Slate and natural stone

Slate is the traditional British house sign material, and for good reason. It is a dense metamorphic rock, effectively waterproof, resistant to frost damage, and it will not fade in sunlight. Engraving cut into it lasts as long as the stone does.

Strengths: exceptional longevity, no maintenance, and a natural variation that suits cottages, stone properties and period homes.

Weaknesses: heavy, which limits fixing options and rules out most adhesive mounting. It is also brittle — slate does not forgive being over-tightened onto an uneven wall. The palette is narrow, and engraved text on dark slate can be hard to read at distance unless it is painted or gilded.

Acrylic (Perspex®)

Cast acrylic is the dominant material in contemporary signage, and the one most modern house signs are made from. It is dimensionally stable, UV-resistant and genuinely weatherproof, and it comes in a far wider range of finishes than any other option: clear, matte, frosted, gloss, pastel, transparent and mirror.

Strengths: light enough for adhesive fixing, available in almost any colour, and it holds a crisp edge — which is why layered 3D lettering is usually acrylic. Matte finishes eliminate glare; mirror and gloss catch available light after dark.

Weaknesses: it can be scratched by abrasive cleaning, so it wants a soft cloth rather than a scourer. Very cheap extruded acrylic is less stable than cast acrylic, so it is worth knowing which you are buying.

Carvica uses cast Perspex® acrylic for colour and detail work, and extruded acrylic where a mirror finish is called for.

Hardwood

Timber brings a warmth that no synthetic material quite replicates, and it sits particularly well against brick and stone. The critical question is species. Softwoods and most furniture hardwoods will not last outdoors in the British climate without regular treatment.

African Iroko is the exception most often used for exterior work. It is dense, naturally oily and used for boatbuilding and exterior joinery precisely because it resists moisture and movement. Left untreated it silvers gradually; oiled, it keeps a deep golden-brown.

Strengths: warmth, natural grain variation, and a material that ages rather than degrades.

Weaknesses: timber is a natural material, so grain and tone vary between pieces. If you want two signs to match exactly, say so when ordering. Wood also benefits from occasional re-oiling if you want to preserve the original colour.

Carvica signs use African Iroko, usually layered with acrylic so the numerals sit proud of the timber.

Metal

Stainless steel, brass, bronze and powder-coated aluminium all appear in house signage. Stainless and aluminium are stable and low-maintenance. Brass and bronze develop a patina — which is either the appeal or the problem, depending on what you were expecting.

Strengths: durability, weight and a sense of permanence. Individual cut metal numerals fixed directly to a wall are a strong modern look.

Weaknesses: cost, and the need to keep dissimilar metals apart at the fixing point to avoid corrosion. Polished finishes show water spotting in hard-water areas.

Composites and printed panels

You will also see aluminium composite, HPL and printed PVC at the budget end. These can look perfectly good on day one. The variable is the print: UV-cured printing on a stable substrate holds up reasonably well, while cheaper inks and laminates fade or delaminate within a few British winters. If a printed panel is very inexpensive, the print is usually the reason.

Side by side

Material	Weatherproof	Weight	Colour range	Best suited to
Slate / stone	Excellent	Heavy	Narrow	Cottages, period and stone properties
Cast acrylic	Excellent	Light	Very wide	Modern frontages, render, any colour scheme
Iroko hardwood	Very good	Moderate	Natural tones	Brick and stone, warm palettes
Metal	Very good	Heavy	Narrow	Contemporary and architect-designed homes
Printed composite	Variable	Light	Wide	Budget and short-term use

The thing that matters more than material

Contrast. A beautifully made slate sign with engraved, unpainted lettering on a dark stone wall is far harder to read than a modest acrylic plaque with white numerals on black. Before you choose a material, decide which element is going to be light and which is going to be dark, and check that decision against the wall itself in daylight.

Fixing is the second thing. Heavy materials narrow your options — slate and metal generally need mechanical fixing, while acrylic and timber can be mounted with standoffs or, on smooth surfaces, industrial adhesive. If you are not permitted to drill, that constraint should drive the material choice, not the other way round.

Maintenance, realistically

• Acrylic: warm soapy water and a soft cloth. Avoid solvents and anything abrasive.
• Iroko and hardwood: wipe clean; re-oil every year or two if you want to hold the original tone rather than let it silver.
• Slate: effectively nothing. Occasional rinse.
• Brass and bronze: polish if you want it bright, leave it if you want the patina. Decide early, because reversing a deep patina is work.

How each material behaves in a British winter

Weather resistance is usually described in general terms. What actually matters in the UK is a specific combination: persistent damp, repeated freeze-thaw cycles, and low winter light.

• Freeze-thaw. Water that gets behind a sign and freezes expands. This is what cracks brittle materials and pushes fixings loose. It is an argument for standoff mounting on any material, because it lets the wall breathe and water drain.
• Persistent damp. Rarely damages acrylic, slate or Iroko. It is the enemy of untreated softwood, MDF and cheap laminated composites, which swell and delaminate.
• Low winter light. The reason contrast matters. Between November and February a subtle tone-on-tone sign can be effectively invisible from the road by four in the afternoon.
• Salt air. On the coast, avoid dissimilar metals in contact at the fixing point, and rinse metal signs occasionally. Acrylic and Iroko are indifferent to salt.

What to ask before you buy

Product pages rarely state everything that matters. Five questions worth asking any supplier:

1. Is the acrylic cast or extruded? Cast is more stable and holds edges better. Extruded is cheaper and fine for some uses, such as mirror finishes.
2. Is the text engraved, printed, or applied as separate letters? Engraved and separate-letter construction outlast surface printing.
3. What timber species, specifically? "Hardwood" is not an answer. Iroko, teak and oak behave very differently outdoors from generic hardwood.
4. What is the numeral height, not the plaque size? The dimension that determines legibility is rarely the one advertised.
5. What fixings are included? Some signs arrive with nothing at all.

Common questions

Which house sign material lasts longest outdoors?

Slate and stone, followed closely by cast acrylic and quality metal. All three will comfortably outlast a printed composite panel. Hardwood lasts very well if the species is right for exterior use.

Is acrylic as durable as slate?

For practical purposes outdoors, yes — cast acrylic is weatherproof, UV-stable and colour-fast. Slate wins on sheer hardness and indifference to scratching; acrylic wins on weight, colour range and fixing flexibility.

Does Iroko wood need treating?

Not to survive. Iroko is naturally oily and weather-resistant. Oiling is about appearance: untreated, it gradually silvers; oiled, it keeps its golden-brown colour.

What does Carvica make its signs from?

African Iroko hardwood and Perspex® acrylic, usually layered together, with cast acrylic for colour work and extruded acrylic for mirror finishes. We do not make slate or metal signs.

See the full range of materials and finishes on our materials page, or browse house number signs and address plaques. If you have not settled on a size yet, start with what size a house number sign should be.