Top Pro Tips on How to Render a House 

12th Sep 2024 -

Rendering a house demands skill and precision. Beyond the basics, mastering advanced techniques can upgrade your work to new heights. This article delves into expert methods for achieving flawless render results and smooth finishes that stand the test of time. 

• How to Choose the Best Render Mix for Advanced Installation Projects
• What is Rendering Using Advanced Techniques?
• Expert Methods on How to Render for Smooth Finishes
• 8 Top Pro Tips on How to Repair Cracks in Render
• Buy the Best Rendering Materials With Fast Delivery

How to Choose the Best Render Mix for Advanced Installation Projects

Picking the perfect render can prove challenging. Below, we compare different render types for you to select the best fit. 

Types of rendering

Render Type	Composition	Best Substrate	Pros	Cons
Cement Render	Portland cement, sand and water	Dense brick, concrete blocks and stone	Durable, low cost	Prone to cracking and not breathable
Lime Render	Lime, sand and water	Soft brick, stone and timber frame	Flexible and breathable	Slower to set and requires skilled application
Polymer Modified Render	Cement, sand and polymer additives	Versatile - good for most substrates	Flexible with good adhesion	Higher cost and specific mixing required
Acrylic Render	Acrylic resin and aggregates	Cement boards and existing rendered surfaces	Wide colour range and fast-drying	Less breathable and can trap moisture
Silicone Render	Silicone resin and aggregates	Insulation boards, cement boards and existing renders	Water-repellent and self-cleaning	Expensive and requires careful application
Monocouche Render	Cement, lime, additives and pigments	Brick, blockwork and concrete	Time-efficient and coloured throughout	Higher initial cost; requires skilled application

Tips on How to Mix Render

• Add liquid ingredients gradually to prevent clumping and ensure even distribution
• For coloured renders, mix entire batches at once to ensure colour consistency
• Use chilled water in hot weather and warm water in cold to control setting times
• When adding fibres or aggregates, incorporate them slowly to prevent clumping
• Let polymer-modified renders stand for 5-10 minutes after mixing, then re-mix before use

When selecting what sand for rendering to use, opt for plastering or sharp sand

What is Rendering Using Advanced Techniques? 

To complement standard rendering practices, there are a range of techniques you should adopt for better outcomes. These methods will make your work look sleek and last longer. Let's explore some exciting ways to level up your rendering skill set. 

Work with polymer-modified renders 

Add polymer additives into your render mix for improved flexibility and adhesion. This increases crack resistance and weatherproofing, making it ideal for challenging surfaces or extreme climates. 

The polymer molecules create a more cohesive matrix within the render, allowing it to flex slightly with building movement. It limits the risk of cracking and improves longevity. Apply polymer-modified renders in thinner coats for best results.

Textured finishes with natural aggregates 

Experiment with adding natural aggregates like crushed shells to your render. Apply using a sprayer for a unique, textured finish that stands out from traditional smooth renders. This technique looks appealing and also improves the render's durability. The aggregates promote UV resistance and provide additional protection against weathering. 

Insulated render systems 

Combine rendering with external insulation for better energy efficiency. Fit insulation boards before rendering a wall, creating a seamless, thermally efficient exterior finish. This system enhances the building's thermal performance and reduces the risk of mould growth. Use adhesives and mechanical fixings to secure the boards. 

Lime rendering for heritage properties 

Lime rendering allows moisture to escape, preventing damage to old structures while maintaining their appearance. Lime render is more flexible than cement-based renders, making it ideal for older buildings that may shift or settle. Ensure you apply in multiple thin coats, allowing each layer to carbonate fully before applying the next.

Colour matching for seamless finishes 

Develop skills in colour matching for a uniform appearance across large surfaces. Use precise pigment ratios and test patches for consistency throughout the job. Consider the effects of weather conditions and how long does render take to dry on the final colour. The render should be applied in complete sections to avoid visible joining lines.

Different exterior wall rendering surfaces 

For an advanced way to render a brick wall, use a base coat followed by a smoother topcoat. This creates excellent adhesion and the scratch coat helps level out any irregularities in the brickwork. 

When rendering concrete, apply a bonding agent before rendering for better adhesion on smooth surfaces. For wood substrates, install a mesh or lath system before rendering to provide a stable base for the material.

Fibrous reinforcement 

Incorporate fibrous materials like glass fibres or polypropylene strands into your render mix. This added reinforcement increases tensile strength (resistance to breaking) and impact resistance. It's especially beneficial for areas prone to thermal stress or physical impacts.

Expert Methods on How to Render for Smooth Finishes

Below, we delve into rendering house techniques that will improve your work from good to exceptional. These methods offer you ways to achieve finishes that stand out for their flawless smoothness and professional quality.

Vacuum troweling

Utilise a specialised vacuum trowel to remove air bubbles and create a smooth surface. To do this, attach a vacuum device to your trowel, which sucks out air pockets as you work. You'll find this effective for large, flat surfaces, reducing the occurrence of pinholes.

Thermal smoothing 

Apply controlled heat to the render surface using a heat gun. This temporarily softens the render, allowing you to shape it more easily and achieve a glass-like finish. Be cautious with your temperature control to avoid damaging the render or substrate.

Polishing compound application

After the render has cured, apply a professional-grade polishing compound using a power polisher with a foam pad. Work in small sections, gradually building up to a high shine. You can achieve a marble-like smoothness with this method.

Micro-cement overlays 

Apply a thin layer of micro-cement over your base render for a smooth finish. It enables you to make seamless surfaces without visible joints; you can tint it to achieve various colour effects. You'll find it ideal for contemporary, minimalist designs.

Foam roller 

Use a high-density foam roller to apply a final, thin layer of diluted render or smoothing compound. This helps you eliminate trowel marks and create a uniform texture across large surfaces. Overall, it’s useful for achieving a consistent finish on ceilings or wall areas.

Compressed air finishing 

Operate a compressed air sprayer to apply a fine mist of water or setting retarder to the surface. It slows down the setting process in specific areas, allowing you extended working time and finer control over the texture. You'll appreciate this, especially in hot or windy conditions that might otherwise cause your render to dry too quickly.

Vibration compaction 

Use a handheld concrete vibrator or adapted sander to vibrate the render surface gently. It helps you consolidate the material, removing air bubbles and creating a denser, smoother finish. Generally, vibration compaction is effective for renders with a higher aggregate content.

Laser-guided levelling 

Employ laser levelling equipment to ensure perfectly flat surfaces across large areas. This advanced technique involves setting up laser guides and using specialised screeds or trowels with laser receivers. 

8 Top Pro Tips on How to Repair Cracks in Render

Rendering repairs often present unique challenges that demand innovative solutions. As a seasoned professional, the below 8 cutting-edge techniques will revolutionise your approach to fixing damaged renderings. 

1. Patching with micro-cement 

Micro-cement works well for seamless repairs on small cracks and chips. The ultra-fine cement blend adheres exceptionally well to the existing render; it can be colour-matched for an invisible repair. Apply in thin layers, building up to the desired thickness. Micro-cement offers superior flexibility, reducing the risk of future cracking.

2. Thermal imaging for moisture detection

Employ thermal imaging cameras to identify underlying moisture issues before starting repairs. This technology allows you to pinpoint areas of water ingress that may not be visible to the naked eye. By addressing these hidden problems first, you ensure your render repair is long-lasting and prevent future damage.

3. Epoxy injection for deep cracks

For deep, structural cracks, use epoxy injection techniques. Drill small holes with a masonry drill bit along the length of the crack and inject low-viscosity epoxy under pressure. It fills and bonds the crack from within, providing structural integrity. Finish with a surface repair to maintain the render's appearance.

4. Breathable repair mortars

When repairing traditional or lime-based renders, use a specially formulated breathable repair mortar. It grants moisture to pass through, preventing trapped dampness and damage. Apply in thin layers, matching the porosity and flexibility of the original render for a seamless repair.

5. Flexible membrane bridging

When dealing with render cracks caused by building movement, flexible membrane bridging will help. Apply a specialised elastic coating over the crack, extending well beyond the damaged area. This creates a flexible bridge that can accommodate future movement while maintaining a watertight seal.

6. Textured spray application for large areas

For extensive render damage, consider using a textured spray application for repairs. You can quickly cover large areas with a consistent finish. Use a hopper gun to apply a textured coating that matches the existing render which is effective for weather-damaged surfaces.

7. Hydrophobic impregnation

After completing repairs, apply a hydrophobic impregnation treatment to the fully rendered surface. This invisible treatment penetrates the render, creating a water-repellent barrier that doesn't affect the surface's appearance or breathability. 

8. Tinted repair compounds

Consider using tinted repair compounds for colour-matched repairs. These specialised materials can be mixed to match the existing render colour precisely. Apply in thin layers, blending the edges carefully for an invisible repair. This is particularly useful for spot repairs on coloured render systems.