Does it matter if you use screed or concrete?

I’m Andy Parkin, Managing Director of the Multi-Award Winning Speed Screed. I’m here to discuss the question of Screed or Concrete?

Concrete and screed have some key similarities, mainly that they contain the same basic raw materials:

• Cement
• Water
• Sand, stone or gravel (the aggregate)

However, the key factor when choosing between the two materials is what you are going to be using them for.

So should you use screed or concrete?

Concrete would be your choice if you were applying the material to construction, in particular, for structural needs.  Screed, on the other hand, is applied to a concrete base to form a sturdy top layer.

How concrete differs from screed

Although both concrete and screed are made by mixing water with cement and aggregate the difference comes when you choose the type of aggregate to mix.

Concrete:  When mixing concrete it is usual to use gravel or another similar aggregate.  This is what gives the concrete its coarse looks and increased strength which lends well to construction and structural work.  The gravel consists of many small stones of around 20mm in size.

Screed:  Screed also contains cement and water but the aggregate is usually sand with small fine grains of 4mm or less.  This means that screed works well as a top layer because it has a finer,  more compacted texture.

The raw materials used and the job at  hand are the key factors when deciding to use screed or concrete.

What about aesthetics?

You will notice that concrete and screed look different and this is because of the coarseness of the aggregate used.  If you are trying to decide whether to use screed or concrete it is useful to take this into account.  The screed will look finer, like packed sand when it has dried.  Concrete is usually used where there is a lot of foot traffic or for structural purposes because it is so tough. It is laid thickly, with a minimum of 100mm for light use and more in heavy-use areas.  Screed is laid more thinly, around 75mm.

To help you decide whether to use screed or concrete, we’ve put together a quick user guide for each of the materials:

Concrete is best used for:

• Foundations
• Driveways & Roads
• Paths with heavy foot traffic
• Walls
• Floors
• Parking and hard standings
• General construction and structural projects

Screed is a good choice for:

• Putting a top layer to concrete floors
• When an underfloor heating system is to be used (it has good insulating properties)
• Aesthetics – tough but better looking than concrete

Other mixtures to add to screed or concrete

Along with the normal mix of ingredients, it is possible to add other mixtures to the screed or concrete.  This includes mixtures to slow down or speed up the time the material takes to set.  Additionally, adding a plasticiser can make the mixture more damp-proof and increase bonding to base layers.  Adding extra fibres can reduce the risk of cracking too.

When looking at screed or concrete you should make sure that the material has a BSI certificate and that your supplier meets the quality standards.  Avoid going for the cheapest option if this means sacrificing quality.

Still confused?

If you are still unsure and are finding it hard to choose between screed or concrete please get in touch with us.  We love to help!