How to Use One Coat Render: A UK Guide for Small Repairs Only

While one coat render is rarely suitable for full elevations, it can work for minor, ground-level repairs on stable substrates. This guide covers safe application steps, critical limitations, and when modern systems like acrylic rendering are smarter long-term investments for your house rendering.

⚠️ Critical Disclaimer:
One coat render is not recommended for:

• Structural walls
• Areas prone to damp or driving rain
• Repairs larger than 1m²
• Homes needing lasting weather resistance

Tools & Materials You’ll Need

*(For repairs <1m² on sound concrete/blockwork)*

• One Coat Render Bag: Pre-mixed polymer-modified (e.g., Everbuild OneCoat, Toupret)
• Bonding Agent: SBR slurry or PVA (diluted 5:1)
• Tools: Hawk, steel trowel, scratcher, bucket, stiff brush, damp sponge
• Safety: Gloves, goggles, dust mask
• Prep: Wire brush, chisel, primer (for high-suction surfaces)

Step-by-Step Application (Small Patch Repair)

Step 1: Surface Preparation

• Remove loose material: Chip away damaged render until reaching solid edges.
• Clean & dampen: Brush debris, lightly mist substrate (avoid pooling).
• Apply bonding agent: Paint SBR slurry onto substrate and existing render edges.

Step 2: Mixing the Render

• Consistency: Add water gradually – aim for thick peanut butter.
• Work fast: Pot life is 1-2 hours. Mix small batches.
• Tip: Never retemper with water once hardening begins.

Step 3: Applying the Render

1. Butter the edges: Apply a 5mm layer to existing render edges.
2. Fill centre: Press render firmly into the patch, overfilling by 2-3mm.
3. Rule off: Use a straight edge to level with surrounding render.
4. Scratch surface: Once firm (20-40 mins), lightly scratch horizontally for key (if painting later).

Step 4: Finishing

• Smooth finish: Trowel lightly with a wet steel trowel after 10-15 mins.
• Curing: Cover with damp hessian/polythene for 48 hours. Protect from frost/sun.

5 Costly Mistakes to Avoid

1. Skipping bonding agent: → Blown render within months.
2. Applying too thick: Max 15mm per pass. Thicker layers crack.
3. Ignoring weather: Don’t apply below 5°C or in direct sun (causes crazing).
4. Painting too soon: Wait 4 weeks before masonry paint.
5. Using on unsound substrate: Always test for hollow sounds first.

When to Use One Coat Render (And When to Call MidRender)

For complex jobs:
Get a Free Quote for Professional Rendering

Why Professional Systems Outperform One Coat

• Scratch Coat Render: Creates a stable base for top coats.
• Acrylic Rendering: Flexible, crack-resistant, 15+ year lifespan.
• Silicone Render: Self-cleaning, breathable, 25-year durability.

💡 Pro Tip:
"One coat costs £8-15/m² but lasts 5 years. Acrylic rendering (£25-40/m²) lasts 20+ years with no repainting. Save 60% long-term."
– Richard Renderman, MidRender

One Coat Render FAQ