Applying render provides an attractive and clean-looking exterior for commercial and residential properties. With a vast range of colours and finishes, there is a lot of choice when it comes to choosing a render system.
Before You Start
It goes without saying but you should ensure unopened packs of render are stored appropriately in a dry place to prevent damp from caking the render. Unprepared render also has a shelf-life, so make sure to check this before using it on a project.
Be confident that you know exactly what the render will look like when dry. If necessary, create a test panel.
When preparing to render a wall, it is also important to assess the type of surface you are working with. Rendering external stone walls, for example, may require additional preparation compared to blockwork or brick due to the uneven and porous nature of stone.
Rendering External Stone Walls
If you are rendering external stone walls, preparation is key. Stone surfaces are often irregular and may contain deep mortar joints or loose material that must be addressed before applying render.
Before starting:
Remove any loose mortar, dust or debris
Repair unstable areas of stonework
Ensure the surface is clean and structurally sound
Lightly dampen very porous stone to control suction
Because stone can retain moisture, it is important to ensure the wall is dry and suitable for rendering. On older properties in particular, choosing the correct render system is essential to allow the wall to perform properly once finished.
Taking extra care at this stage will help prevent cracking, poor adhesion or long-term performance issues when rendering stone substrates.
Getting Started
First, make sure you have all your tools ready and the render has been made up according to the instructions.
Most renders can be applied by hand or with a spray machine – make sure to check which type of application is suited to your render.
Apply the base coat to the required thickness and allow it to cure before applying any further coats.
Curing
Render needs time to cure, which is best achieved in warm, moist conditions. The initial curing process should be closely monitored over the first 2–3 days – the render should be kept from drying out, shielded from direct sunlight and protected against frost. Make sure to check the instructions on your render for any additional precautions or advice specific to your render.
Render needs time to cure effectively over a period of 3 weeks to achieve its final colour, and the render should be kept protected from inclement weather such as rain and high winds during the 24–48 hours immediately after application.
Extra care should be taken when applying render in cold conditions. It is not recommended to mix or use render if the temperature is below 5°C as cold temperatures slow the curing of the render and freezing temperatures halt the process entirely.
Finally, if you are in doubt about how to render a wall, do not hesitate to contact our experts who will be happy to help with any issues you may have.