Insulated Render for solid walls
EXTERNAL INSULATED RENDERING is a term used to describe a combination of external rendering and an insulation cladding. Instead of trowelling on a sand and cement render directly to the brickwork you first attach a thermal layer of cladding to the outside wall surface by affixing with a powerful adhesive and then drilling and pinning the thermal cladding to the underlying wall .
How New is Insulated Rendering
In the UK outside has been around for about a dozen years in any great volume but using external has been standard practice across Germany and Europe for over 5 decades as they prefer to build and then fit external thermal insulation to the outside to obtain U values far superior to those achieved in the UK.
At home the application and production of insulated render systems is closely monitored under the Building Regulations to ensure best practice is followed and in the majority of cases a home-owner will need to file a Building Notice with their Council.
Can Insulating Render Cut Heat Loss?
YES,external insulation renders for solid walls are all independantly tested and then examined during application by Building Control Inspectors to ensure they insulate the walls properly and effectively. Turn down the thermostat and start saving around 35% of your heating bills say the Energy Saving Trust.
In fact, 50mm of the leading exterior insulation board – Kingspan K5 Kooltherm – has approximately the same insulation effect as a 4.5 feet thick brick wall! As most walls that need an external insulated render tend to be around 9 inches thick you can see the enormous difference an exterior insulating render system will have on your home.
For those keen to maximise thermal efficiency in their homes you can go up to 200mm of external insulation cladding as long as there is sufficient ventilation within the home to allow moisture to escape the home at the appropriate rate to avoid excess humidity.
Do Insulating Render Systems Vary
YES. There is a lot of choice in the type of thermal cladding used, the finished look of the rendering itself and also a very wide colour choice.In other words there really is something to suit every home and a lot of scope to dramatically alter the appearance of your home when using an external insulated render.
Solid Wall Insulation Grants?
EcoCare can access partial grants for solid wall insulation under certain circumstances. Unlike loft and cavity insulation there are no full grants for solid wall houses and no direct Government subsidies either for the “able to pay” home-owner looking to have the full costs of external solid wall insulation covered.
However, there is some funding available to meet part of the costs. For the home-owner wishing to keep warm with reasonable heating bills there are small External Instulation Grants available regardless of income. Below is a brief summary of the current help available for insulation of external walls in a solid wall property but this does vary over time.
The Chancellor of the Exchequer recognises the importance of cutting energy use and has levied a 5% vat rate on external insulation as opposed to a standard rate of 20% . This 15% subsidy is very welcome and it represents a saving of around £1500 on a typical sized 3 bed semi-detached solid wall property.
The External Walls Intallation Process
Only the highest quality kingspan external K5 insulation boards are fitted using a special adhesive render. This resin based adhesive is very powerful and is buttered onto the rear of the insulation board before being laid onto the wall in bonded brick pattern. The boards are then further secured by being mechanically drilled and pinned to the wall and at the base of the wall the boards sit in a stainless steel or aluminium base rail set at the height of the damp proof course.
Once the thermal cladding boards are in place two layers of a specialist polymer bonding render is trowelled onto the boards and nylon meshed in readiness for the decorative and weather proof final coat. This forms an incredibly strong bond with the external wall insulation board but also has the ability to flex and breathe so as not to trap moisture in the walls or in the outside insulation itself.
The final weather proof and decorative render is then trowelled on to give a beautiful lightly textured finish. The renders we use on exterior insulation panels are laced with glass fibre strands which allows them to flex with the thermal movement of a property ie crack proof and to need no decorating or maintenance for at least 20 years.
The finished look often includes newly extended window cills and repositioned down pipes as a consequence of the extra depth created by the solid wall insulation board system.
Here on the right the home-owner has chosen a Papida brick slip to cover the chimney and lower wall area to add character and interest to the look of the home. As with the render finish brick slips are also affixed directly onto the insulation boards and do offer a different option to all external wall insulation systems on solid wall homes.