Probably one of the hardest parts to the wet trades, Rendering is a tough cookie to crack. But it is a beast that can be tamed. And I’m going to show you the full process on how to render walls…in crystal clear detail!
Now, there’s 5 stages to rendering a wall and I’ll explain everything from the video below. This comes from our Youtube channel and it’s probably the best way to outline the process. And it’s by showing you.
However, I’ll also recap each stage so make sure you read the entire article to get the most from this tutorial. Because there’s a lot to get through…so watch the video first! (And be sure to like and subscribe to our channel if you liked it 😉
5 Stages On How To Render Walls
So the 5 stages on how to render a wall are:
- Applying the scratch coat
- Scratching the render
- Applying the top coat
- Ruling & Floating the top coat of render
- Sponging the render (FINISH)
There’s are the 5 main stages to rendering. And each is as important as the next one…but there’s a few questions to answer first. And the main one is this:
Why 2 Coats Of Render?
As you can see from the 5 stage process, there’s obviously 2 coats of render applied to the wall. And that’s for the main reason of strength and also appearance. If you have 1 coat of render then you only have 1 layer of protection.
This means there’s a greater chance of weather damage. It also means that there’s less thickness to deal with the original brickwork/ block-work of the building. This means that the render can often look unprofessional and to put it bluntly…amateur.
You won’t get a professional finish in rendering with 1 coat of render. You’ll never get it completely flat and the block-work will always shine through your work. So never try 1 coating – it isn’t worth it. But one thing I need to explain on how to render walls is this.
Stage 1: Applying The Scratch Coat
The First stage is applying your first coat of render. And the first coat of render is called a scratch coat (we’ll go into that in a minute). Now, applying the render can be tough…but it’s not impossible for a beginner.
You just have to make sure that you never miss the Golden Rule:
NEVER PLAY WITH THE RENDER.
Once you’ve applied the render to the wall make sure you don’t try to trowel it flat. You can trowel the render a few times but you want to avoid overworking the render with your trowel. One of the big things I’ll teach you on how to render walls is that you can’t compromise the fixing of the render.
Let me explain…
If you trowel your render with a steel trowel then the metal pulls the moisture from the back of the render and pulls it to the front. Now, this may sound a bit scientific but it’s extremely important…and here’s why:
Render Without Moisture FAILS
If your render dries out then you’ll be in massive trouble! The render will either fall of the wall or it will crack when dry. And that’s because it’s the moisture that gives the render it’s grip to the wall…it’s the moisture that provides a key.
So always make sure you do 2 things:
- Spray your walls down with water before rendering
- Avoid drying the render out
This means skipping over trowelling. And also avoid working in direct sunlight! The heat will drain the moisture from your render making it extremely hard to finish. This also effects it’s strength when it’s dried.
So after you’ve applied your first coat of render you…
Stage 2: Scratching Your Render
So you have your first coat of render on the wall – now it’s time to give it some waves. Sounds mad but we’re going to apply some pretty lines to our work. But it’s not to make it look nice…
It’s completely practical. And here’s why!
Your top coat will never stick to your first coat if you don’t provide some grip. And in the plastering world, we call it a mechanical key. A mechanical key is basically the process of applying traction in the form of lines. We use a Plastering Scarifier:
The picture above shows you everything you need to know. It’s a simple process but extremely important. If you skip this step then the top coat of render will literally fall on the floor…it’s pretty important!
Now ideally you’d leave your Scratch Coat of render to dry for 1 day. Then it’s time for stage 3 of the rendering process:
Stage 3: Applying Your Top Coat Of Render
So this is pretty much the same process as stage 1 – we’re just applying render. What we do afterwards is different but the process for this is the same. You just want to apply the render as flat as you can, without playing with it.
And always remember to spray your scratch coat down with water beforehand. You still need to soak your scratch to provide a key for the next coat of render. You can’t forget the Golden Rule because it always counts. And it’s the difference between success and failure!
But if you stick to what you’ve learnt then I can almost guarantee success!!
But what we do now is totally different. Instead of scratching the render we need to start making it flat. Which leads us nicely to…
Stage 4: Ruling Your Top Coat Of Render
I personally think that this is the hardest stage to render walls. This is a dark art and it takes a lot of practice to get right! It’s also crucial because your results afterwards depends solely on this stage.
Getting this wrong will lead to your wall looking like the Rocky Mountains so pay close attention to this bit! Because the way you get your wall flat in rendering is by ruling and floating it smoothly.
This is the magic formula to flat walls. And this is the biggest thing to learn on how to render walls for complete beginners.
Now, there’s plenty of tools you can use for the job but first let me explain what each tool is and how it works. The first tool is called a Rule or a Straight Edge. This is basically a long, straight piece of steel and you literally pull the render flat. So once you’ve applied your render you use the rule to get it flat.
You pull any high spots of render from the wall and then fill any areas that are low. You then repeat the process until your whole wall is covered and flat. The tool I use is called a Featheredge.
Now, there is a cost to getting your wall flat. It can often leave the render looking rough and often torn from the flattening process…this is completely normal by the way. But we need to fix it! And this comes from the floating process.
The Float is basically a flat piece of plastic or wood. And you use this tool to completely flatten your wall. The problem when Ruling is that you won’t ever get your wall completely flat because the Render still needs to be wet to perform that action.
It’s only when your render has firmed up that you can then Float and flatten your wall to the best level. And all you do is put your float flat to the wall and with circular motions remove any high spots and fill any low. Now, this sounds really strange and it’s actually hard to describe.
Which is why I’m going to just show you how it’s done. The video below outlines how to finish render and it’s mainly about floating which is why you need to watch it. Check it out because this is probably the most in depth guide you’ll find on the internet…you can’t afford to miss it 😉
Stage 5: Sponging Your Wall (FINISH)
You’ve made it!! You’re at the final stage of plastering.
And you’ll be happy to know that it’s actually the easiest stage of plastering. If you’ve done everything else correctly then you’ll find this part a doddle!! All we’re doing here is giving your rendered wall that magic touch.
And we’re literally going to sponge the wall.
Now, I know what you’re thinking and we’re not cleaning it. We’re giving your wall a traditional Sand & Cement finish. And the process is simple.
You take a damp sponge and with circular motions, (similar to the motions you’d follow when Floating), polish your render. This process closes in any grit and brings the sand to the surface of your wall.
It’s a very satisfying job and it makes all your hard work totally worth it!
But the big secret here is to always keep a clean sponge. Whenever you’ve been sponging always clean it off in a clean bucket of water. This stops the render from collecting on your sponge and prevents any marks from being scored in your finished render.
And always keep a soft touch. You don’t want to push hard on the sponge – just let it do the hard work. The softer your touch the better the finish. Watch the video above and I’ll show you exactly what I mean. It’s worth watching.
And that’s it! You’ve learnt how to render a wall. There’s a lot to learn here but trust me…it’s doable. Just take your time and start on a small area first! If you’ve enjoyed this article then please subscribe to our Youtube channel.
And keep checking in. For another approach to rendering check out the other article on how to render walls. I talk about the mix, which tools you’ll need for the job and also show another example on how to render a wall. It’s a must for anyone who’s serious about learning.
So check it out from this link here.
Thanks a lot for choosing us. I’ll see you soon…Cheers,