My Top Tips for 2014: Rendered Walls
What you need to know about rendered walls
Rendered walls are a mainstay of contemporary garden design, and a very popular choice as a main feature in so many of our schemes. Getting rendered walls right, however, is about much more than just plonking them in place. The effect they achieve is hugely dependent on things like intelligent associative planting, dramatic or soft lighting, and a host of other important factors. I’ll run through these factors here – everything you need to consider, from planning to maintaining a rendered wall.
Building the basics
The first thing to think about is the situation your wall will be in – that is, is the wall going to be free-standing, or retaining? While both need to be well built, of course, they need to be built differently. If the wall is lower, quite modest, and free standing, it need only be built with ordinary 15cm concrete blocks. However, if the wall is big or retaining, make sure you don’t use anything less than 2x10cm concrete blocks with a cavity between. Another crucial feature of retaining walls is a good waterproofing paint, and weep-holes that are connected by a land drain, with a buffer zone for granular material immediately behind the wall if the wall is retaining soil. Properly built, the wall will last a long time, and during that time you want to make sure you never have any drainage issues!
Choosing your render
There’s a whole world of opinion out there about rendering. I’ve broken it down into three options. I’ve used them all with some success, so what you choose is up to you and your garden:
(a) Sand and cement: a regular sand and cement mix (4:1) with some added ingredients, including a good waterproofing agent. For the sand, some renderers like ordinary rendering sand, while some prefer to use a softer type known as Waddington Fell. This type of render would be used as a scratch coat followed by a top coat, and the wall will typically want three coats of masonry paint (textured or smooth) on top.
(b) K-Rend: this product is already used extensively on houses and garages, and its use on garden walls is on the up. I would recommend this if you are looking for a textured effect. The downside is the limited range of colours and the fact that, although this can be painted, it is basically a colour-through render. K-Rend can also stain quite stubbornly when rainwater splashes onto soil, and is more difficult to get off than the simple sand and cement render.
(c) One coat render: as the name suggests, this is a much simpler option, but be aware that this will still require a follow up of two to three coats of masonry paint.
For a clean, light, Mediterranean look we often go with a white or off-white colour on our rendered walls, which provide perfect backdrops for all sorts of gardens. More recently we have been building feature walls which stand out more – we’ve done everything from pale grey, to soft red, and even bright green. These feature colours are powerful tools for setting the tone of the scheme, and can often be used sparingly for best effect, alongside other more muted walls.
Hard weather and Coping
Our rendered walls are often most effective when simple and uncomplicated, so we often do not use a coping, allowing rainwater to simply run off the top of the wall. Of course it is possible to have very attractive rendered walls that have copings, without detracting from the contemporary effect. This could take the form of a simple stone or slate coping, and is something you might want to consider if your wall will be subjected to especially harsh weather.
I always make sure clients realise that the luxurious and aspirational look rendered walls give a garden depends on their pristine appearance. Good maintenance is really essential. While there is no hard and fast rule, as gardens will differ, I would say that most rendered walling would benefit from a fresh coat of paint at least once a year.
Make it your own
While these rules are pretty universal, you can see that there are a lot of choices to be made in the construction of each rendered wall, leaving room for a wall that is bespoke and perfect for you exact scheme. Some clients take this a step further, for example using rendered walls with free standing stainless steel water features for a really dramatic look, even incorporating seating, as in the image below. How would a rendered wall work in your garden?