Pebbledash, a once-prevalent feature in British home architecture, is a unique and rugged exterior finish. Its creation involves applying a wet mortar mix to walls and then pressing small pebbles or gravel into the surface. This technique provides a robust, weather-resistant layer and adds a distinctive texture and character to the buildings. However, the charm of pebbledash can fade over time, leading to a dated appearance that many homeowners wish to refresh or completely overhaul. The texture of pebbledash, with its rough and uneven surface, presents specific challenges and opportunities for renovation. The techniques to cover up old pebbledash vary.
In this blog, we will guide you through the nuances of pebbledash — its composition, its initial appeal, and the reasons it may now feel outdated. We will then delve into detailed methods for covering or replacing pebbledash, ensuring your home’s façade reflects contemporary styles while preserving its structural integrity. From choosing the right materials to understanding the application and maintenance process, we aim to equip you with all the knowledge you need for a successful exterior makeover.
How do I get rid of pebbledash?
Pebbledash became extremely popular in the 1920s due to increased demand for homes. This led to builders cutting costs and using pebbledash to cover up poor brickwork. This has resulted in an outdated and, for many, unsightly look that many homeowners are looking to remove.
If the right materials aren't accessible, re-rendering pebbledash without removing the pebbledash can be difficult. Removing pebbledash is painful because removing the render requires hard work with a hammer and chisel, with the added risk of damaging the original brickwork. Typically, pebbledash is made from sand and cement render, an incredibly unforgiving material often applied to cover up a bad build job.
With the growing popularity of coloured render, pebbledash has taken a bit of a hit of late, with pebbledash house prices falling to reflect a national dislike. Nonetheless, as long as the pebbledash is in good condition, it can’t be rectified without the expensive process of removing it.
How to re-render pebbledash without removing
So, how do you re-render Pebbledash without removing the Pebbledash? There are a couple of ways, which we will explore.
Smoothing over the pebbledash with One Coat Dash Cover (OCDC)
One of the best ways of re-rendering pebbledash without removing the pebbledash render is by smoothing over it with our One Coat Dash Cover (OCDC). This is the ideal material because it can be applied at a thickness of 20mm without compromising structural integrity. You wouldn’t want to put a non-breathable material on top of the pebbledash because water needs to escape from the walls; otherwise, you may be in an unpleasant, waterlogged situation.
The first step in re-rendering your pebbledash is to ensure that any loose stones are rubbed off.
The next step is to prime the pebbledash using the 310 Universal Primer. This will limit the absorptive capacity of the pebbledash render and ensure that any dust is settled; it also provides a good grip for the basecoat to adhere to.
Once the primer has been left to set for 12 hours, you can start preparing the OCDC for application. One 25kg bag needs to be mixed with 5 litres of clean water using an electric paddle mixer. Once mixed, leave for 2-3 minutes before re-mixing and apply to the substrate using a plastering trowel. We recommend embedding Fibreglass Mesh within the basecoat, overlapping each strip by 10cm to ensure crack resistance and tensile strength.
Once the initial 5-20mm coat has been set, apply a ‘tight coat’ using a plastic, metal or felted float. After this has been set, we advise applying a thin coat render such as Silicone Render; this is highly breathable and available in a wide range of colours, providing an aesthetically pleasing finish. To learn more about this technique, please check out our YouTube video, 'One Coat Dash Cover'.
Externally insulating on top of the render
Another method of re-rendering pebbledash without removing the pebbledash render is to apply insulation boards to the existing pebbledash. Even 20mm of EPS insulation secured to the property's exterior can increase its thermal efficiency and create a smooth surface for a fresh layer of render to be applied to. The preparation method is the same: loose pebbles should be removed, and the wall should be primed with the Universal Primer.
The insulation boards should then be secured to the substrate using the 225 Premium Basecoat. This should be applied to the whole back of the insulation boards—we don’t recommend using the dot-and-dab method for applying insulation to pebbledash. Mechanical fixings should also be used to secure the insulation boards to the pebble-dash.
Once the boards are set in place, you should have created a new substrate for re-rendering pebble-dash without removing pebble-dash. The best practice is to rasp to EPS to achieve a smooth surface and remove the oily top layer, and then you can apply your render basecoat. We recommend using the Premium Basecoat for extra strength, embedding fibreglass mesh within the basecoat to ensure a strong and stable surface for the render. Finally, you can prime the basecoat using the SiSi Render Primer, leaving it to dry for 12 hours before applying the Silicone or Silicone Silicate render.
New process for covering pebbledash
As we constantly progress and innovate, we are reviewing our product ranges. As a result, One Coat Dash Cover is due to be phased out at some point in the next 12 months. This means we have had to devise a new way to treat pebbledash. As our products are extremely versatile and deliver exceptional performance, we have been able to design a new solution with existing products. One Coat Dash Cover will replace Lightweight Basecoat in the pebbledash system. The application of the basecoat works in exactly the same way. You must apply what is essentially a parge coat to level the surface completely. The level surface provides a dimensionally stable surface to further basecoat and render your facade.