Exterior wall render and paint buying guide
Dennis, self-taught DIYer, Bristol18 guides
- Traditional render
- Monocouche render
- Facade paint
What is render?
The 3 types of render
- Cement render (sand + cement)
- Lime-based render (sand + lime + possibly cement) ;
- Plaster finish.
- Lime-based renders are particularly easy to use thanks to their slow drying process. They also excellent insecticides.
- Cement renders, on the other hand, are more hardwearing.
Traditional or monocouche render
Render is traditionally cement- or lime-based (or a mixture of the two) and is applied with a trowel in three layers.
- The first bonding coat has a runny consistency and is trowelled on in a thin layer.
- The second layer is a straightening coat which gives depth to the render and allows you to level out inconsistencies; this is applied with a float.
- The third layer is a finishing coat used for aesthetic purposes.
However, monocouche render cannot be applied over plaster or earth-based substrates such as cob. It has a lifespan of 30-50 years.
Choosing the right render for your surface
It's crucial to choose the right render depending on the surface you're going to apply it over.
Generally speaking, it should be softer and less waterproof than its supporting surface.
In the vast majority of cases, walls will be made of concrete block, concrete or bricks. A highly water-repellent industrial render with a thickness of 10-15mm is perfectly suited to these materials.
Which rendering finish to choose?
Choosing your render also means choosing the finish. There are four main types: sprayed, crushed, scraped and trowelled.
Spray finishThis is the classic render finish. Render is projected onto the substrate using a compressor hose or Tyrolean gun. A second coat is applied a few hours after the first. The rough surface will make the facade appear darker due to the texture it creates.
Trowel finishFor a trowel finish, the render is smoothed with a plastic trowel or sponge, giving a smooth but grainy appearance.
'Ready-made' renders are typically sold in 15kg tubs and simply need to be diluted before application. These will generally cover an area of about 15m² and can either be trowelled on or applied with a roller.
What is interior render?
Many types of render can be applied indoors using a roller. Interior render is usually made from acrylic resin, and is designed to decorate or freshen up old surfaces.
In terms of application, a special honeycomb roller is recommended. Choose your grain size according to the desired result (this will dictate the size of the small 'spikes' or protrusions in your render finish).
What are the different types of exterior wall paint?
Pliolite / hydropliolite
Pliolite paints can be cleaned off using white spirit-type solvents. Hydropliolite paints offer similar performance but can be cleaned with water.
Specialist exterior wall paint
When choosing a paint, your substrate is a key deciding factor along with the location of your home. You'll need to choose a paint that is suited to the surrounding environment.
Wet and wooded environments
Final tips for choosing your exterior wall render and paint
Please note that exterior wall colours may be regulated by local authorities, more general regulations or, of course, by housing developers / associations (if you live in a block of flats). It may be necessary to obtain planning permission for substantial alterations to the exterior of your property. You can keep up to date with UK regulations here.
Dennis, self-taught DIYer, Bristol 18 guides écrits
I started doing DIY 10 years or so ago, when I bought a house that needed to be renovated.
After having installed loft isolation, and having refurbished the bathroom, the toilets, the kitchen, the bedrooms… I built an extension, installed a new fence with a gate and kitted out the house with a solar panel to make hot water. I have poured tens of tonnes of concrete into slabs or into the foundations and renovated the roof… I can say that building materials and tools are no stranger to me!
If I had a pound for every hour spent looking up information in forums and DIY magazines to find solutions to my problems, I'd be a millionaire! So passing on my knowledge on tools and home equipment is natural, as it is just giving back what I borrowed.