
I am currently in the middle of a job where today I started laying engineering bricks for a raised flowerbed which will naturally act as a retaining wall for the raised soil behind. We had the choice between using engineering bricks or facing bricks but since engineering bricks had more advantages in terms of strength and stability as well as them being more cost effective, this is what we opted for. This got me thinking however, what if someone wants to build a wall themselves? If you are a DIY person and like to take on jobs yourself then this doesn’t mean that you know which bricks to use for your next project. Whether it is a raised flowerbed you are building or a new brick-built shed, here are the differences between engineering and facing bricks to help you decide on which will be best for your project.
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What is an engineering brick?

For the most part, engineering bricks are not made for their aesthetic value. There are no requirements when it comes to the look, colour or texture of an engineering brick, instead they are made for their added strength, making them more able to withstand extreme conditions.
The biggest difference between engineering and facing bricks are that engineering bricks have holes (also known as perforations). If you are building a wall where the top of the wall will be on show, then these holes will be on show too which wouldn’t look great at all. These holes do however serve a very important purpose and that’s for the mortar to seep in when laying the bricks and locking the bricks together. A structure built from engineering bricks will be sure to stand the test of time.
Not only this, but engineering bricks have a higher water resistance rating compared to facing bricks. This makes them great for continuous damp and freezing conditions which is why you’ll often see them used for retaining walls where they continuously hold back wet soil, soakaways, tunnels and sewers.
What’s the difference between class A and class B engineering bricks?

If you’ve been looking into purchasing engineering bricks then you might be confused by seeing different grades of bricks available. Luckily there are only 2 options available which are class A and class B and neither have anything to do with their aesthetic values. Instead they have everything to do with their compressive strength and water absorption values.
Class A engineering bricks
The strongest of the 2 types of engineering bricks are labelled as class A. These have a very low water absorption rating at just 4.5% or less and have a high compressive strength of 125N/mm2.
Class B engineering bricks
As a landscape gardener I’ve only ever used class B engineering bricks and they’ve always been more than adequate for the job. Their water absorption rating isn’t much different at 7% and they still have a good compressive strength of 125N/mm2.
What are facing bricks?

If you are building an external wall that will always be on show and so you want it to look good then the facing bricks will likely be what you are looking for. Unlike engineering bricks where they are made only for their compressive strength and water absorption rating, facing bricks are instead made for their aesthetic values which is why they are commonly used to build external walls to homes.
Facing bricks are great as there are so many options to choose from which include their colour, texture, pattern and even size, making them perfect for any project where the look of the wall is important. This can be the external wall of a new home or extension, a gated wall outside your property or even a fancy shed where you want the bricks to match your home.
Can you use engineering bricks as facing bricks?

You can’t use facing bricks as engineering bricks as they lack the water resistance properties and strength for the project in question, but what about the other way round? Can you use engineering bricks as facing bricks? After all, they are usually cheaper to buy and despite not being made for their aesthetic properties, there are many engineering bricks that look great.
Yes, you can use engineering bricks as facing bricks but you do have just 1 problem and that is the holes. From the side of your newly built wall, you won’t see the holes and will look like any other bricks but from above, you will see the perforations. If you won’t be able to see the top layer of engineering bricks from above, for example a shed roof will be going on top, then engineering bricks will be fine. For smaller walls such as a raised flowerbed or external wall around your driveway then you just need some coping stones to finish off the top layer of bricks, hiding the perforations. On this particular job where I am building a raised flowerbed, I will be cutting porcelain paving slabs and laying them on top. I will be sure to add pictures as soon as I’m finished!