What is the main difference between silicone and acrylic render?

Silicone render is hydrophobic (water-repellent) and vapour-permeable, allowing moisture to escape from the wall while repelling rain. Acrylic render forms a more impermeable coating that is highly flexible and crack-resistant but less breathable. Silicone render is the premium choice for UK climates due to its self-cleaning properties in rain.

Which render is more expensive?

Silicone render is more expensive. Material cost is typically £25-40/m² for silicone (e.g. K Rend Silicone) vs £15-30/m² for acrylic render. Total installed cost including basecoat, mesh and topcoat is approximately £50-80/m² for silicone systems vs £35-60/m² for acrylic. The premium reflects the superior weather performance and longer maintenance-free life.

Does silicone render really self-clean?

Yes, silicone render has genuine self-cleaning properties. The hydrophobic surface causes rainwater to bead and run off, carrying dirt particles with it. This keeps the facade cleaner for longer — typically 10-15 years before any noticeable discolouration, compared to 5-8 years for acrylic render. North-facing or sheltered walls may still develop algae over time regardless of render type.

Which is better for crack resistance?

Acrylic render is slightly more flexible and elastic than silicone, giving marginally better crack-bridging ability. However, both modern renders are applied over a reinforcing mesh on a basecoat, which provides the primary crack resistance. In practice, both systems perform well against hairline settlement cracks when properly applied with mesh reinforcement.

Can I apply silicone or acrylic render myself?

Both renders are technically demanding to apply well. Silicone render is especially unforgiving — it must be applied in consistent passes without visible joins. Both require a proper basecoat with embedded mesh, primer coat and then the topcoat. Most manufacturers (K Rend, Weber, Parex) recommend trained applicators and may void warranties for DIY application.

Silicone vs Acrylic Render Compared

Compare silicone and acrylic external render systems for UK buildings, covering flexibility, self-cleaning, colour range, cost and application methods.

Side-by-Side Comparison

Feature	Silicone Render	Acrylic Render
Material cost per m²	£25-40	£15-30
Installed cost per m²	£50-80	£35-60
Water resistance	Hydrophobic — beads water	Good — but absorbs more
Breathability	Highly vapour-permeable	Lower vapour permeability
Self-cleaning	Yes — rain washes dirt	Limited
Flexibility	Good	Excellent
Colour range	Wide (factory-mixed)	Very wide (factory-mixed)
Maintenance-free life	10-15 years	5-8 years

When to Choose Silicone Render

Exposed sites with heavy rainfall (most of the UK)
Walls that need to breathe (solid walls, timber frame)
Premium finish with long maintenance-free life
Properties where clean appearance is important
K Rend, Weber or Parex system specifications

When Acrylic Render Is Suitable

Budget-conscious projects where cost matters more than longevity
Sheltered walls not exposed to driving rain
Surfaces prone to movement where maximum flexibility is needed
EWI systems where the insulation provides the vapour control
Vibrant or unusual colours not available in silicone ranges

Related Calculators

Use the Rendering Calculator for material quantities, or the Monocouche Render Calculator for through-colour render systems.

How We Calculate This

Frequently Asked Questions

Last updated: April 2026

All calculations are estimates. Verify with your supplier.

Silicone vs Acrylic Render Compared

Side-by-Side Comparison

When to Choose Silicone Render

When Acrylic Render Is Suitable

Related Calculators

How We Calculate This

Frequently Asked Questions

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