Rendering is a layer of hard-wearing plaster applied to external walls to protect a building from the damaging extremes of weather. Rendering is a technique that has been used for centuries, with many different types of materials being used over it's long history. Most of these have been natural products that were growing or found naturally in the locality such as timber and clay. These days mud and dung renders are thankfully not as popular as they were in the past, but wood and lime are still used alongside modern plaster based renders. Technology is improving all the time and today's materials are robust and durable, giving a smooth contemporary finish that lasts for many years before needing to be renewed.
As well as protecting your building from the elements, applying external render to your house also has the effect of making your home far more energy efficient. It's thought that around thirty per cent of domestic heat is lost through normal external walls, but this is vastly reduced by the addition of render plaster on the outside. Therefore good quality rendering will help to save the planet as well as the cash in your pocket!
It's important to be clear what modern plaster rendering looks like. The word itself often conjures up images of the drab grey pebble dash of 1960s, but that's a world away from the stylish products that are available on the market today. Modern renders give an elegant clean look to a building and are available in a range of contemporary colours and textures. The recent additions of silicone and acrylic to traditional plaster renders has allowed for greater durability, flexibility and usually a maintenance-free lifespan. Smooth or textured surfaces can be either painted to suit, or pre-injected with a colour of your choice prior to application.
Rendered houses today look clean and flawless, with clear bold lines toned in attractive modern colours and shades. The materials in modern render will not only protect your building from potential damage from wind and rain, but they will also save you money on your heating bills as well as updating the look of your property. A professional render will add value to your home and increase both its status and saleability.
Whatever the style of your property and whatever your budget, there are a wide range of render options to choose from. Whether you're after smooth or textured, traditional or modern, there is a render to suit your needs.
A Handy Guide to Renders
Cement based renders are an extremely common form of external render used throughout the world. Based on a mix of cement and sand, they often have lime added to them to reduce cracking when drying. They are a good cheap and hard-wearing option and are relatively easy to apply allowing for a smooth or textured finish depending on the techniques used. Any outdoor paint can be used to colour them once dry, however, they do require regular painting to keep them maintained. Concrete renders can be brittle though, and are subject to cracking should there be any settling or movement of the underlying building. Cement renders are usually mixed on site and often require several coats of varying coarseness to apply.
Lime Renders have been protecting the walls of buildings in Britain for centuries, and they have seen a recent revival in popularity as their usefulness and practicality are being rediscovered by a new generation of eco-aware consumers.
In the past they were often applied to walls built of poor quality brick or rubble stone to protect against the extremes of weather, and are still an excellent choice for period properties today.
Because they made from natural products, they have the ability to absorb water from rainfall and then release it by evaporation thus preventing moisture penetrating the walls underneath. They also work by allowing any moisture from inside the building to pass through the walls without being trapped. This ability to 'breathe' stops damp and mould from accumulating and prevents the building from decaying. This makes it a popular choice for renovation projects and conservation work in older houses where modern materials may not be desired or suitable. In the past, the application of non-breathable concrete renders on period properties has caused significant damp formation and even structural damage to occur.
Lime renders also have the added advantage of being extremely flexible, and will bend and stretch with the underlying building if it moves or settles in any way. Unlike concrete renders they do not crack under structural pressure, but will extend and contract with the natural shift of the building. Even modern buildings move more than most people realise, and period properties in particular, especially those of timber-frame construction, are subject to motion caused by changes in temperature and weather as well as settling of the ground underneath.
Lime also has natural fungicide properties and will help prevent the growth of mould on exterior walls, keeping buildings healthier and looking clean and well-maintained. Alongside all this, the beautiful natural finish of lime renders greatly enhances the appearance of both modern houses as well as older ones. Unlike modern renders, however, they usually require reapplication every four to five years, but are otherwise maintenance free.
All in all, lime renders are generally a far superior product to most cement-based renders but unfortunately they do require more skill to apply. This is a factor that has therefore usually been reflected in the costs of lime rendering. However, recently, many companies have been introducing new high-tech lime render products intended to be easier to use but still retaining all the advantages of this traditional product. The addition of silicones into products such as K-Lime, brings this age-old rendering material into the modern period
These are a fairly new type of render which is based on a traditional cement render mix but with specially selected polymers added to it. Unlike normal cement renders they are extremely flexible and elastic and so will not crack under pressure of movement or settling. They are also extremely durable and largely maintenance free over a long period of time.
Polymer products are usually premixed and can be pre-coloured and through-coloured so that there is no need to paint once they have been applied. This is a particular advantage for high-rise buildings and those that have exteriors that are harder to regularly maintain. They come in a wide range of contemporary shades and textures guaranteed to suit any modern home or commercial building. They are usually premixed and only require water to be added to prepare them for application. This means that the quality of the render remains consistent and gives a superior finish over the entire building.
As they are silicone based, most polymer renders will still allow the underlying property to adequately breathe, preventing the accumulation of damp or trapped moisture. Several of these products are even self-cleaning which is ideal for those buildings where there is lots of vegetation and the risk of organic overgrowth.
These are any kind of render that have a plastic acrylic added to their formula. This allows the render to be stronger and far more flexible than traditional cement based render so they do not crack after application. Acrylic renders have the ability to form an impenetrable barrier to water yet still allow the building underneath to adequately breathe.
They are also resistant to mould and bacteria. and are extremely fast drying allowing painting to commence just a few days after application. They are manufactured in a wide variety of different finishes and textures allowing for a full range of contemporary looks to choose from. Acrylic renders do not degrade in UV light, and are incredibly weather resistant.
Acrylic renders are also easier to apply and can be rolled, trowelled or even sprayed onto a surface, forming a thin coat formed of fine acrylic hairs lying in alternate directions to create a highly flexible mat coating. Acrylic renders can be applied to a wider range of surfaces than concrete render, including already painted walls, concrete and timber.
K-Rend are a leading British plaster manufacturer who have helped to popularise the use of silicone in modern renders. They are probably the most popular rendering products available on the market in the UK at the present time. Silicone is both highly water repellant and self-cleaning, and is therefore largely maintenance free.
K-Rend manufacture a number of different products, for every kind of property. They come in a range of colours and finishes, and are extremely durable and hard-wearing.