Render finish over Pebble Dash

Hello Matt It is possible to render over pebbledash but you must be sure to use the appropriate products. EWI produce a range of suitable products, one of which being EWI-065 One Coat Dash Cover (OCDC). EWI advise the following, when rendering over pebbledash: Step 1 – Substrate Suitability Check Ensure that the pebbledashed wall is stable and secure by knocking the existing substrate with a shovel or hammer. Loose pebbles should be removed, and any areas of crumbling pebbledash should be stripped back completely. Step 2 – Priming the Substrate Apply a layer of EWI-310 Universal Primer to the substrate. This will increase the adhesion between the pebbledash and the OCDC, and ensure that the substrate is stable. Step 3 – Applying OCDC OCDC should be mixed with 5 litres of water per 25kg of dry mixture. In order to level out the wall, apply the first pass of OCDC (up to 20mm) to the areas where the Pebbledash has been stripped back. Once the first pass has set the second pass should be applied to the entire substrate, taking the total thickness up to a maximum of 50mm. Fibreglass Mesh should be embedded within the second pass of OCDC to enhance its tensile strength. A plastic, metal or felted float should then be used to create a smooth surface. Step 4 – Applying the Decorative Finish Once the OCDC is completely set, you are ready to apply your decorative finish. At this stage, you can choose to either render or paint the substrate. For painting the substrate, EWI (obviously) recommend using the EWI-005 Silicone Paint. This creates a breathable, waterproof surface that is resistant to environmental pollutants. When rendering the substrate, EWI suggest using a silicone-based render, such as EWI-075 Silicone Render. This is highly breathable and hydrophobic, with self-cleaning capabilities to ensure a clean surface for years to come. I hope this helps. Tristan

Hi Mat, It is possible to render over the top of your pebble dash. In my opinion, the best product(s) to use would be a silicone or acrylic based render system. Whilst the material cost is higher than traditional sand and cement render finishes, there is absolutely no need to remove the existing render and incur additional labour and waste removal costs, and there is no need to decorate either! Best practice is to remove any loose stone/pebbles from surface with a stiff broom head or hand brush before any work commences. A high adhesion primer is then painted, rolled or sprayed over the entire surface and left to cure (24 hours). All beadwork (10mm beads will suffice for this application) is either mechanically fixed, or wet fixed using some base coat render and reinforcing mesh. A polymer modified base coat is then applied, including reinforcing mesh covering every square metre of substrate, with additional stress patches at corners of door and window apertures. Once the render is fully cured (dependant on weather but usually 2-3 days) a colour equalising primer is applied. This primer helps to control the suction of the substrate for improved workability, but also prevents any grin through of the base coat render as it is matched to the through coloured topcoat. This needs to cure for approximately 24 hours. The final, through coloured and thin coat render finish is then applied. These systems are highly breathable, flexible and water repellant and will significantly improve the aesthetic appearance of your property. Some of the systems even offer improved thermal performance. There is a lot of information available on these systems. I would recommend checking out Ecorend.co.uk as their website provides some comprehensive information, and they are very competitive on cost compared to other manufacturers. I hope this helps? Kind Regards, Leigh Wilkinson

Yes it can be cover with a smooth render, it's a scratch coat over the top of the pebble dash with a mesh I bedded to stop any cracking or any hollowness of the render

I'm not 100%sure I would recommend taking pebble dash off for a better finish

What mesh did you use for pebbledash was it the fibre mesh ?