Painting over a render involves a variety of paint types. It’s not as simple as using a paint stirrer, grabbing a paintbrush and applying wall paint to a rendered wall. A wall render is generally a combination of sand, cement and polymer. Paint will need to be able to stick to these components so choosing the right paint for rendered walls is important.
Painting a rendered wall requires the use of vinyl paints and prep work. Vinyl or PVC paints are usually two-component paints that come mixed in a cartridge.
Vinyl paint may also be referred to as embossing enamel, solvent-based enamel, PVC enamel or vinyl coating. They are available in many different sheens including matt, satin and gloss with good covering properties that can be thinned with white spirit for easy application.
Painting Newly Rendered Walls
If you are repainting a newly rendered wall, the paint will need to be especially tough. The rendering can be contaminated with efflorescence crystals that dissolve into the render during the drying process and these often have sharp edges that scratch through thin coats of paint. For this job choose an enamel paint specifically designed for new renders (avoid acrylics).
One fairly recent innovation in small-can painting has been the development of methyl ethyl ketone (MEK) paints. These contain MEK which is much more volatile than white spirit or turpentine so they dry extremely quickly allowing you to apply several coats in quick succession. They also cover well and harden like epoxy but without curing time. As long as you use a good quality brush and stir the paint well before use, you will find these a valid alternative to vinyl paints.
Painting Existing Rendered Surfaces
When painting over an existing render surface, you have much more choice in what type of paint you can use depending on the state of the wall. If there is efflorescence present it must be chemically removed as described earlier otherwise the crystals will dissolve into any paint applied and cause bubbles to appear as they rise up through the new coat.
If you are unsure whether or not your render has been stripped back enough then it’s worth bearing this in mind when considering what type of paint to buy. Vinyl enamel paints should only be used on properly prepared renders so if your wall requires further work it’s best to opt for epoxy paint.
Can You Paint Render?
Get professional help If you want to paint over a wall render, it is best not to attempt this yourself. You will need a roller, paint tray, roller pole, paintbrush, different colours to choose from and stir with a paint stirrer. Most importantly there are many dangers involved in painting and rendering and if the wrong type of paint is used, bubbling and blistering could occur.
Professional paint contractors fully understand what types of paintwork goes best with which renders so for your peace of mind, leave the job in their hands. They also have all the tools such as paintbrush, paint tray, paint roller and more. You will be able to choose from a range of styles and tones when they come to do the job so you can add that all-important personal touch to your home.
How to Paint a Rendered Wall?
Professional painters supply the appropriate materials and help you choose the right paint for your rendered wall. Here are some tips on how to paint a rendered wall.
- Remove all furniture, ornaments and electrical fittings from the walls. If they cannot be moved safely, mask them with polythene sheets or nylon netting secured by duct tape or adhesive tape.
- If your render is damaged, apply a coat or two of a suitable primer before you start painting. This will help to seal the surface and ensure that the paint doesn’t come away from the wall as soon as it comes into contact with moisture.
- Invest in good-quality brushes for small jobs such as painting over renders. This will improve the final finish and reduce the chance of brush strokes being visible after the work has been completed.
- Turn off all electrical power to areas where you are going to be working. You can re-connect them when you have finished but only when the paint is completely dry.
There are many types of paints designed specifically for use on a rendered wall. You can choose between acrylic, vinyl and epoxy paints. Vinyl paint is the cheapest of these three options but it has a relatively short lifespan. Acrylic paints are more expensive than vinyl but they last about five times as long before needing to be reapplied on any rendered walls.
Epoxy paints offer excellent protection against damage from water and weathering so they can be used on both interior wall rendering and house exterior.
These paints cover well and dry very quickly to give a smooth, professional-looking finish so if you want good value for money, use the right paint designed for rendering.
One of the main reasons renders crack or come away from walls is because they have not been properly prepared before the paint is applied. Prep work is important. This preparation may include:
- Repairing cracks and holes in the surface
- Applying a bonding agent, such as white spirit or methylated spirits, to make sure that the render adheres well to the wall
- Applying a primer coat of paint or sealant as recommended on the container
The paint you choose should be suitable for your particular type of render. For example, some paints have additives that will cause them to crack when used on stucco renders so these must not be used on this kind of surface.
Once the preparation work has been completed, painting can begin. The painting process is the same for both interior and exterior walls, apart from any special requirements you may have to account for. A render paint job must be done by a professional, especially if you are painting on an exterior wall. They have the equipment necessary for the painting job can have a quality finish.
How to Use Drop Sheets?
Drop sheets are canvas or plastic sheets that are laid over the floor of the room so you don’t have to paint all the skirting boards, door frames and furniture. Tape the drop sheet tightly to any surfaces that you don’t want to be painted, such as electrical fittings. Use masking tape for this job. Tie the handles of the drop sheets together on one side if it is possible to do so.
What Paint to Use for Cement Rendering?
When it comes to choosing the right paint for your job, check what type of render you are working on. This will enable you to choose the appropriate paint for that surface.
The most suitable paints for rendered walls are epoxy or acrylic paints designed specifically for that purpose. These paints are very quick drying and colourfast, which means they won’t fade in sunlight. They also provide excellent protection against weathering and water damage because they don’t allow moisture to penetrate through them into the rendered walls underneath.
The next best option is vinyl emulsion paint because its thicker consistency makes it easier to apply roller evenly onto a rendered wall and reduce brush and roller marks and orange peel effect (the rough finish caused by coats of paint not containing enough binder). If you use emulsion paint, it is better to use a matt rather than a gloss finish so you don’t get too much reflection from the surface.
How to Prepare Your Render for Painting?
In order to prepare your rendered wall for painting, follow these steps.
Clean away any flaking or loose render from the surface of the wall with a stiff brush and water solution. Talk to your building supplier to find out whether they have a recommendation for specific cleaning products that should be used on different types of wall surfaces (for example, lime-based rendering generally requires strong alkaline detergents). Rinse your walls with clean water once you are done brushing off any debris. If there are areas that still need repairing, mix up some patching compound or filler and apply it to the damage.
When your wall is dry, vacuum them thoroughly with a small paintbrush attachment. Don’t forget to remove any residue from inside corners and around nails, screws or other fasteners that may be on the wall. You should also take off all door and window hardware, using masking tape for areas that you think might get messy (such as over knobs). Use an old dust sheet or tarpaulin so these items can be easily covered when painting begins. If there is staining on your render, you’ll need to treat this before applying paint because stains will repel water-based paints, which means they won’t stick properly to the surface.
Even though paint manufacturers recommend you clean your walls with warm soapy water, I use methylated spirits to remove dirt and grease. Mundane activities such as cooking create a residue that will repel paint, so any grime or stains are usually removed after this type of cleaning.
Methylated spirits are also good for removing surface dust from render surfaces because it’s very strong. I find that just one wipe with a rag soaked in methylated spirits makes the render look new again (and it doesn’t matter if it has been there for 30 years!).
Always check the manufacturer’s recommendations on whether my rendering needs to be sanded before painting, but generally speaking, don’t bother because most require no preparation. However, some older readers will need a good once-over with medium-grade sandpaper before painting, to remove any excess oils that have leached into the surface over the years. This is particularly the case when painting onto precast concrete surfaces because their porous nature allows them to absorb oil from vehicles.
Paint for Cement Render
As I mentioned earlier, epoxy paints are highly recommended for rendering jobs because they provide excellent protection against weathering and water damage. They also don’t allow moisture to penetrate through them into the surface underneath which would cause water penetration problems (and then further deterioration).
Other benefits of using epoxy paint include its quick drying time (meaning you can get on with other things quicker) and colourfastness. This means it won’t fade over time due to the high concentration of pigments.
Epoxy paints tend to be more expensive than emulsion paint, but they offer far superior performance in the long run.
Paint for Stucco Rendering
To make your stucco walls weatherproof you’ll need to use an acrylic-latex based product because earlier versions were only effective on porous surfaces. Fortunately, most of these problems have been sorted out by using new technology that creates a thicker coating of paint over the surface.
Paint for Brick Rendering
If you are painting onto painted brick, then use an acrylic-latex based paint to ensure maximum adhesion. This type of paint is also suitable for unpainted brick or stone walls, but in that case, use water-based paint because acrylic-latex products won’t stick to them properly.
Conclusion for Painting Over a Rendered Wall
Before starting your painting job, always check with the paint manufacturer to ascertain whether you need to take any specific steps before beginning. It wouldn’t hurt to ask a well-informed rep at a specialist paint store as well because they will know if their product requires any special attention.
By following these tips for painting over cement render or stucco, you should end up with a job that lasts the distance. Always remember to clean and sand the surface properly and use the right type of paint colour for the job. Contact professional painters via an email address, add to cart your best paint for painting a rendered wall and wait for the project to be completed by the painter.