A Homeowner’s Guide to Caring for Different Render Types

As a homeowner, you may not give much thought to the exterior walls and rendering on your property. But this protective coating plays an important function – shielding your brickwork or masonry from weathering damage and providing a decorative finish. Proper maintenance is crucial for extending the lifespan of rendered walls.

There are a variety of different render types used on houses nowadays. Each blend has its own characteristics, advantages and ideal cleaning methods. Some require more frequent care to look their best over years of exposure to rain, sun, pollution and other elements. Finding the right balance of wash downs, sealant renewals and prompt crack repairs can save thousands in rendering repairs down the road.

In this post, we’ll overview the most widespread types of modern render you’re likely to find on exterior walls in the UK. We’ll briefly cover what gives each their unique properties and performance. More importantly, you’ll learn specific tips to care for the exact render finish on your home properly.

 

Types of Render

Acrylic Render

One of the most popular forms of external home wall coatings in the UK is acrylic render. As its name suggests, this render type contains acrylic polymer resins as a key ingredient blended with fine aggregates like sand or quartz. Pigments are also added to give the textured finish a durable colour tint.

Thin coat render

Unlike traditional cement rendering, acrylic provides a more flexible protective barrier that copes better with natural expansion and contraction of the walls over seasons. It helps insulate the masonry or brickwork underneath against temperature changes. The elasticized acrylic texture is also quite effective at bridging over hairline cracks that form as buildings settle.

Compared to other options, acrylic render is relatively straightforward to clean and maintain. Light mould or algae growth can be removed without much hassle using household cleaners or diluted bleach solutions. A low-pressure rinse once every year or two clears away deeper dirt buildup. Harsher chemical cleansers and aggressive scrubbing should be avoided though, as it could damage the acrylic binders near the surface.

One downside is that the vivid colours you see when acrylic render is freshly applied will gradually fade over 5-10 years. At this point, a new acrylic skim coat or paint will be needed to restore it aesthetically. However, the original base coat should still adequately protect the structural walls behind it. Catching any cracks early and filling them prevents costly underlying damp issues.

 

Silicone Render

One of the premium rendering solutions for UK homes is exterior silicone render. It provides ultimate water resistance thanks to the silicone resin binders mixed into the topcoat finish.

The silicone polymers make the coating highly impermeable to water, yet still permeable enough to allow water vapour to escape from inside walls. This breathability ensures the masonry can dry out rather than trapping moisture, which prevents issues like frost damage or cracks from wet expansion over winter.

Unlike acrylic mixes, silicone render keeps repelling rainfall even after many years of exposure. The colour pigmentation also holds up better under UV rays, rarely needing a refresh. What’s most impressive is the flexibility and durability of the set coating. Silicone render can stretch and compress over 100 times more than cement before cracking.

On average, it takes at least 15-20 years before reapplication is recommended. When that time comes, a simple power wash to clean the surface followed by a fresh topcoat of silicone masonry paint restores the water resistance and aesthetic appeal.

For homeowners wanting lasting, low-maintenance exterior walls, the upfront investment into quality silicone rendering pays dividends for decades. Keeping on top of annual moss/mould cleaning is advised along with resealing any entries like pipework or windows if necessary.

 

K-Rend Render

One prominent brand of silicone-enhanced render popular across the UK is K-Rend. This system consists of a base coat formulation and a specialised K-Rend top coat applied on top.

The K-Rend base layer is hand-applied over brick, block or concrete substrates to smooth and level the surface. It contains cement blended with well-graded fillers to improve adhesion as it sets.

The proprietary K-Rend finish coat goes on top – available in a variety of textured styles. This contains silicone water repellents, polymer binders and coloured aggregates. It provides long-lasting resistance to algae and mould growth thanks to the silicone waterproofing additives.

Cleaning requirements are also minimal thanks to the water-shedding nature of the silicone-enriched topcoat. K-Rend only advises low-pressure hose rinsing every 8-10 years unless unusual soiling occurs. Harsh chemicals or scrubbing risks damage, so caution is needed.

With expert application and the premium silicone enrichment, a crisp K-Rend rendered finish should keep walls protected for 20-30 years or more.

 

Mineral Render

Mineral renders provide a traditional lime-based coating for exterior walls, used for centuries across the UK and Europe. As the name suggests, these incorporate mineral components like crushed stones or silicates blended with cement, lime, sand and water.

Modern mineral renders offer breathability, allowing water vapour to pass through instead of trapping moisture against the masonry. However, they aren’t fully waterproof against driving rain like acrylic or silicone blends. Without sufficient protection from elements, some staining, algae growth or efflorescence deposits can occur over time.

Cleaning a mineral render every 2-3 years helps limit build-up issues. Use a low-pressure rinse to avoid driving excess water into the surface. Any damaged areas with cracks or spalling concrete will need swift repairs. Replacing any worn sealant around adjoining windows or doors prevents leaks through the gaps too.

For listed heritage homes that require traditional finishes, mineral renders suit the natural, porous limestone appearance. They do need more careful maintenance though compared to polymer renders. Catching problems early and not allowing vegetation direct contact keeps them looking clean longer.

 

Monocouche Render

Over the last decade, monocouche renders have surged in popularity across UK residential projects. As the name hints, this is a single-coat system that creates a decorative, textured finish in one quicker application.

Monocouche consists of a polymer-modified cement blend mixed with well-graded aggregates, silicone water repellents and pigments. The precisely calibrated ingredients set fast, bonding as a highly durable surface coating. Being cement-based, it still allows some vapour permeability.

A major advantage for installers is avoiding a separate base coat and finish layer with monocouche rendering. The single render application saves time and money compared to traditional sand and cement. It also copes better with shrinkage cracks as the building underneath naturally settles.

Most monocouche render only requires cleaning every 5-7 years. When the time comes, caution is still needed with pressure washing to avoid eroding the surface. Check manufacturer guidelines for additives approved to remove stubborn staining or mould.

While a long-lasting choice for low maintenance, keeping vegetation or organic matter touching the walls can accelerate discolouration. Trimming back overgrown plants protects the crisp finish. Any cracks appearing should be sealed quickly as well to prevent lasting water damage.

 

Cement Render

The traditional cement and sand render mix has been used for centuries across the UK. This type contains Portland cement blended with sharp sand, lime, water and sometimes a dash of plasticizer.

Cement-based renders provide good compressive strength and weather resistance at a reasonable cost. However, they are more rigid and prone to cracking compared to more modern polymer-modified alternatives. Without an acrylic, silicone or other protective topcoat, plain cement render is also porous to liquid water over time.

Prevention is most important to keep a cement render finish looking its best long-term. Addressing hairline cracks early and keeping the surface clear of debris avoids water damage or organic growth taking hold.

Every 3-5 years, low-pressure washing clears dirt buildup which can accelerate wear. Harsher jet washing or scrubbing should be avoided though, as it risks eroding the surface further.

Catching small problems before they turn bigger is advised. Monitoring for bowing, sagging or holes appearing indicates the render may be failing. Sorting underlying causes like leaks or rusted wall ties prevents further detachment.

With vigilant maintenance, cement render still performs reasonably well in lower-exposure areas. But for extreme wet conditions, improved polymer types provide longer-lasting protection.

Considering a DIY approach to applying render? Check out our comprehensive guide on how to render a wall.

 

Conclusion

There are clearly quite a few options when it comes to rendered exterior wall coatings nowadays.

The key for homeowners is properly maintaining whichever type protects your walls. Follow manufacturer-suggested care guidelines and wash cycles.

Catching mould or algae early prevents it from taking hold. Reapply protective sealants and paints when needed to renew weather resistance.

Not allowing organic debris prolonged contact keeps walls staining free longer too. Trimming back vegetation stops dampness issues arising from moisture retention against the surface.

Finally, fix any cracks, holes or other render damage promptly before water seeps underneath to structural walls. This saves extensive repairs in future.

With the right render choice for your property and keeping on top of basic care every few years, you can expect decades of like-new longevity before a full replacement is needed.

If you require any render cleaning or maintenance services, please don’t hesitate to get in touch with us. Our team specialises in safely restoring all types of external wall surfaces. We also offer affordable render refresh packages; bringing back that as-new sheen your property deserves.