Acrylic Render vs Silicone Render: The Real Differences

What acrylic and silicone render are

Both are thin-coat render systems. On a typical wall, the build-up is the same: beads at corners and openings, a base coat with reinforcing mesh bedded into it, a primer, and a thin through-coloured finish coat, usually just a few millimetres thick. The real difference is in that finish coat.

Acrylic render uses acrylic resins as the binder. Acrylic is a type of polymer, which gives the finish strength, flexibility and good resistance to cracking and impact. See our acrylic render page.

Silicone render uses silicone resins, often combined with other binders. Silicone gives the finish strong water repellency while allowing water vapour to pass through, so the wall can breathe. See our silicone render page.

Both sit within the wider family of modern through-coloured systems described in our guide to exterior rendering. Because the base layers are similar, the two are often offered by the same manufacturers as alternative finishes within the same system. That’s why it’s worth understanding the difference before you choose, rather than leaving it to whichever finish happens to appear on the quote.

Acrylic vs silicone at a glance

indicative Ballpark figures; your wall, access and region matter more than the finish.

Breathability: the key difference

Breathability — more precisely, vapour permeability — is how easily water vapour can pass through the render. It matters because walls take on moisture from rain, from the ground and from inside the house, and that moisture needs a way out. A render that lets vapour escape helps the wall stay dry; one that slows it can trap moisture.

Silicone is highly vapour-permeable for a modern render. It keeps liquid rain out while letting vapour escape, so the wall can dry outwards.

Acrylic is noticeably less breathable. On a modern cavity wall or an external wall insulation system, that usually isn’t a problem, because those constructions manage moisture differently. On a wall that relies on drying through its outer face — especially an older solid wall — it can contribute to moisture building up behind the render.

This is usually the deciding factor in choosing between them. If there’s any doubt about the wall’s ability to manage moisture, silicone is the safer choice. Manufacturers publish technical data on vapour permeability for their finishes, and a good renderer will be able to tell you how the specific products being quoted compare, rather than relying on general claims about either material. If you’re comparing two quotes, it’s a fair question to ask both renderers.

Water repellency and staying clean

Silicone’s other big advantage is water repellency. Rain beads on the surface and runs off, carrying dirt with it, and the surface dries quickly. That makes silicone particularly good at staying clean and resisting green algae, especially on north-facing, shaded or exposed walls.

Acrylic is water-resistant and keeps rain out of the wall well, but it isn’t as strongly water-repellent at the surface. It can attract and hold dirt more readily over time, and on damp, shaded walls it may show algae sooner. On a sunny, sheltered elevation, the difference may be modest; on a shaded or exposed one, it can be very noticeable after a few years.

Both benefit from occasional gentle cleaning with a suitable render cleaner, avoiding high-pressure washing, which can damage the finish. Our guide to algae on render explains the causes.

Toughness, impact resistance and cracking

This is where acrylic shines. Acrylic finishes are tough, flexible and highly resistant to knocks and scuffs, which makes them a good choice for walls that take wear: ground-floor elevations next to paths and driveways, areas where bikes and bins are kept, walls next to play areas, and commercial or communal buildings.

Silicone is also durable and flexible, and well able to cope with normal domestic life, but where impact resistance is the priority, acrylic has the edge. Some homeowners use acrylic on a particularly vulnerable ground-floor area and silicone elsewhere, though using one finish throughout is simpler and gives a more uniform look.

Both acrylic and silicone are flexible finishes applied over a base coat with reinforcing mesh, so both resist cracking far better than traditional cement render. Their flexibility lets them accommodate small movements in the wall without cracking.

In practice, cracking in either system is far more often down to the base layers, the wall or the installation than to the choice of finish: missing mesh at the corners of openings, render applied over unsound surfaces, or movement in the building itself. A well-installed system with full mesh and proper detailing matters much more than acrylic versus silicone here. Our guide to render cracking explains what causes cracks and how each type is put right.

How much more does silicone cost?

Acrylic is usually a little cheaper. As an indicative guide, acrylic typically costs around indicative £60–£90 per m² and silicone indicative £65–£95. Our acrylic render cost guide breaks down what sits inside the acrylic figure.

On a whole house, the difference is often modest, because everything else — scaffolding, preparation, beads, base coat, mesh, primer, sills and fittings — is essentially the same for both. The saving from choosing acrylic is mostly in the finish coat.

As purely illustrative arithmetic: on 100 m² of wall, the indicative ranges work out at indicative £6,000–£9,000 for acrylic and indicative £6,500–£9,500 for silicone — a gap of around £500 at either end. Real quotes are priced for the whole job, including scaffolding and preparation, so use the wall-by-wall bands in our house rendering cost guide for a whole-house picture.

Given that, silicone’s better breathability and cleaner appearance often justify the small premium on a house you plan to live in long term. See our silicone render cost guide for the silicone side in detail.

What about silicone-acrylic hybrids?

Many manufacturers offer finishes that combine silicone and acrylic resins, sometimes called silicone-enhanced or hybrid renders. They aim to combine some of silicone’s water repellency with acrylic’s toughness and lower cost. Their performance sits somewhere between the two, and varies between products.

If you’re quoted a hybrid finish, ask the renderer for the specific product and its technical data, particularly its breathability and water repellency, so you can judge where it sits. On walls where breathability matters, a full silicone or mineral finish may still be the better choice.

Which walls suit which render?

Modern cavity-wall homes. Both are suitable. Silicone is the better all-round choice for appearance and low maintenance; acrylic is a sound value option, particularly on sheltered elevations.

External wall insulation (EWI). Acrylic finishes are widely used on insulation systems, where the construction is designed to manage moisture differently. Silicone is also common on EWI, especially where a cleaner long-term finish is wanted.

Older solid-walled houses. Breathability matters most. Silicone, a mineral (silicate) render or lime is usually more appropriate than acrylic. Our silicate vs silicone render comparison covers a more breathable mineral option; on historic buildings, lime is often the better answer still.

Exposed, coastal or shaded elevations. Silicone, for its water repellency and resistance to algae.

High-traffic or impact-prone areas. Acrylic, for its toughness.

Colours and finishes

Both are available in wide ranges of through-coloured shades, from bright whites through creams, stone and greys to deeper tones, and in similar textures — typically fine scraped or textured finishes in different grain sizes. From the street, a well-applied acrylic and a well-applied silicone in the same colour look very similar.

Over time, the difference shows mainly in how clean they stay. A pale silicone finish usually stays brighter for longer, which is one reason silicone is often chosen for white and cream renders. For strong or dark colours, ask about the specific product’s suitability, as dark finishes absorb more heat from the sun.

Lifespan and maintenance

Both can last many years when properly installed on a suitable wall. The quality of preparation and installation affects lifespan far more than the choice of finish. Maintenance is similar: no painting, occasional gentle cleaning, keeping gutters and sills in good order, and dealing with any damage promptly. Silicone usually needs cleaning less often.

Repairs to either are made by cutting out the damaged area and rebuilding the system, then matching the finish coat. Through-coloured repairs can be hard to colour-match exactly on a weathered wall.

Application, systems and guarantees

The application process is almost the same for both: preparation, beads, base coat with mesh, primer and finish coat, with curing time between stages and protection from frost, rain and strong sun. The finish coats handle slightly differently, and manufacturers specify their own primers and application conditions, so it’s important the renderer follows the specific system’s requirements rather than mixing products.

Because the systems are so similar, many renderers apply both, and a good one will recommend the finish that suits your wall rather than the one they happen to prefer.

Both acrylic and silicone finishes are usually sold as part of a complete render system from a single manufacturer — base coat, mesh, primer and finish — and manufacturer guarantees typically depend on using the full system, applied to their specification, often by a trained or approved installer. Mixing a finish from one manufacturer with base coats from another can void that cover.

Ask which system is being used, whether the installer is trained on it, and what guarantee comes with it. Our render guarantee guide explains the types and what they cover.

Common myths about acrylic and silicone render

“Acrylic is plastic, so it’s low quality.” Acrylic resins are widely used in durable exterior products. Acrylic render is tough and long-lasting on the right wall; its limitation is breathability, not quality.

“Silicone render is waterproof.” It’s strongly water-repellent, which isn’t quite the same thing. It sheds liquid rain while still letting water vapour escape, which is exactly why it’s good for walls. A truly waterproof coating would trap moisture.

“They look completely different.” On the day they’re applied, a good acrylic and a good silicone in the same colour and texture can be almost impossible to tell apart. The differences show in performance and in how they age.

“The finish coat is the whole render.” The finish is only the top few millimetres. The base coat, mesh and preparation beneath do most of the work in keeping the render sound, and they’re the same for both.

How exposure and location affect the choice

Where your house is, and which way each wall faces, can tip the balance. Elevations that face the prevailing wind and rain — often west or south-west in much of the UK — take the most weather, and silicone’s water repellency is most valuable there. North-facing walls get little sun, stay damp for longer and are the most prone to algae, which again favours silicone.

Coastal homes face salt-laden air and driving rain, and homes near trees face shade and organic debris; both are situations where silicone’s cleaner surface pays off. Sheltered, sunny elevations in urban areas are the least demanding, and there acrylic’s small saving may be perfectly reasonable.

It’s worth walking round your house with this in mind. Some homeowners choose silicone for the whole house simply because one or two elevations are demanding, which keeps the finish uniform.

Acrylic and silicone on external wall insulation

External wall insulation systems fix insulation boards to the wall, then apply a reinforced base coat and a thin finish. Both acrylic and silicone finishes are commonly used on these systems. Because the insulation changes how the wall handles heat and moisture, the system manufacturer specifies which finishes are compatible, and that specification should be followed for the system guarantee to apply.

Insulated walls have a cold outer surface, which can make them more prone to algae and dew forming on the finish. That’s one reason many installers favour silicone or silicone-enhanced finishes on insulation, particularly on shaded elevations. Ask your installer which finishes the system allows and what they recommend for your house.

Insulated render systems are a different price bracket from either finish on its own: as an indicative guide, around indicative £90–£150 per m², excluding scaffolding and removal of any old render. Our guide to external wall insulation render explains the system.

Questions to ask your renderer

Which finish would you recommend for my walls, and why? How breathable is the specific product you’re proposing? Are my walls solid or cavity, and does that change your recommendation? Is it a pure silicone, a pure acrylic or a hybrid? What would the price difference be on my house? Is the finish part of a full manufacturer system with a guarantee?

A renderer who answers these clearly, with reference to your house, is likely to recommend the right finish.

Our recommendation

Choose silicone if you want a highly breathable, water-repellent, clean-looking thin-coat finish; your walls are exposed, shaded or north-facing; the house is older or you’re unsure how the wall manages moisture; or you want a pale render to stay bright.

Choose acrylic if the wall is a modern cavity wall or insulation system, the elevation is sheltered, impact resistance matters, and you want to save a little on the finish.

If in doubt, choose silicone. The price difference on a whole house is usually small, and silicone is the more forgiving choice across a wider range of walls. On a pale colour in particular, it tends to keep its clean appearance with less attention.

Three example scenarios

A modern semi re-rendered on a sunny, sheltered street. Either works. Acrylic saves a little; silicone will likely stay cleaner on the shadier rear elevation. Many owners choose silicone throughout for consistency.

A detached house with a north-facing side gable under trees. Silicone, for its resistance to algae and staining on the shaded wall.

A block of flats or a house with a busy side passage used for bikes and bins. Acrylic on the vulnerable ground-floor areas is a sensible, durable choice, or acrylic throughout on a modern construction.

Refreshing an existing acrylic or silicone render

If your house already has an acrylic or silicone render that’s looking tired, you may not need to replace it. A gentle clean with a suitable render cleaner often restores much of the original appearance. Where the render is sound but stained, faded or patched, a specialist may be able to clean and prepare it and apply a new finish coat over the top — and that’s a natural moment to switch from acrylic to silicone if staining has been a problem. Where the render is cracked, hollow or failing, it needs repairing or replacing before any new finish goes on.

Not sure which finish you already have? The most reliable answer is in the paperwork: the original quote, invoice or guarantee should name the system and manufacturer, and the manufacturer can confirm the finish. Without that, a specialist will look at how the surface behaves, but a weathered wall can be hard to read, so treat any on-the-spot verdict as an informed opinion rather than proof. It matters because the new finish coat has to be compatible with what’s underneath, and some systems call for a specific primer or bridging coat when one finish goes over another.

Comparing acrylic and silicone quotes

If one quote specifies acrylic and another silicone, they’re not directly comparable. Ask each renderer to price both finishes on the same specification — same preparation, base coat, mesh, beads, scaffolding, sills and fittings — so you can see the real difference on your house. Check each quote names the system and manufacturer. If one renderer quotes a hybrid, ask the other to price the same product so all three options are on the table.

When neither might be right

On historic solid-walled houses, lime or a mineral render is often more appropriate than either. If your brickwork is sound and attractive, re-pointing may be all it needs; see our guide on whether to render or re-point. And if appearance is the only concern on an existing render, some homeowners compare masonry wall coatings too, a different product worth weighing on its merits.

If you’d like expert advice, SmartMatch™ weighs render-type experience, verified reviews, online reputation, insurance and accreditation to introduce you to one vetted local specialist for a free, no-obligation survey and quote. Compare the finishes in more depth on our silicone render and acrylic render pages.