What is a Screed?

Screed is a mixture of cement, water and sharp sand applied over a concrete base. It can also be applied to a solid concrete slab or precast concrete floor unit.

Materials for Floor Screed

The materials used for the construction of the floor screed are as follows:

  • Cement
  • Clean and sharp sand
  • Water
  • Occasionally, a few additives are added to get specific properties
  • Polymer material
  • Metal or glass mesh is sometimes added to strengthen the screed

What is Floor Screeding?

Floor screeding is applying a well-mixed screed mixture to provide a smooth floor finish, ensuring that it is evenly applied around fixtures, soil pipes, ducts, thresholds or/and underfloor heating pipes. What’s more, it can be applied to every shape and size of floor.

How is Screed Used?

When the top floor layer is added, an uneven floor can be an issue regarding the floor’s structural integrity; therefore, laying a screed can help resolve the issue. 

It is applied to protect the concrete subfloor. It can bear constant use and heavy footfall and has excellent insulation capabilities, making it the most popular and ideal choice with underfloor heating systems.

A perfect thin levelling screed can add to and enhance the structural performance of the floor.

Once you clean and lay the screed, make sure you leave it for 16 hours or at least two days, depending on the type of screed you are using. 

On the other hand, the amount of screed depends on various factors, such as how uneven the floor is and your project’s initial purpose.

What are the Different Types of Screed?

The most common types of screed are: bonded, unbonded and floating. Each one is used according to the type of concrete base, conditions and the client’s requirements. Each type has its speciality; however, you need a good foundation to make the best of whichever type of screed you use.

  • Bonded Screed:

Bonded screed must be applied directly to the concrete slab with an adhesive, and to do so, the surface of the concrete must be rough. Bonded screed is an ideal choice where heavy loading is anticipated. It usually involves a thickness of 15mm to 50mm, though 25-40mm is perfect. 

Furthermore, one thing to remember is that you must thoroughly clean the area before applying the bonding screed.

  • Unbonded Screed:

Unbonded screed is applied on top of a damp-proof membrane, splitting it from the concrete base. It is an outstanding choice for severe and excessively damp areas.

Moreover, with an unbonded screed, it is essential to keep an eye on the drying process; if left unattended, it will dry too fast the edges of the screed will fold and wrap.

Unbonded screed are best for thicknesses exceeding 50mm.

  • Floating Screed:

Floating screed is an unbonded screed; however, it is applied on a layer of insulation, acoustic, or thermal layer. This screed is generally used in underfloor heating structures. It necessitates a thickness of 50-65mm, even 75mm, for immensely heavy-loaded floors.

Moreover, if underfloor heating is installed, the thickness of the heating pipes is a minimum of 25mm.

The procedure of Floor Screeding

  • Examine the surface of the base
  • Evaluation and estimate of the materials used for screeding
  • Preparation of base
  • Preparation of screed mixture
  • Application of bonding materials like water, bonding slurry or adhesive
  • Place the floor screed mixture
  • Lastly, properly cure the materials of the place

How is a Successful Screed Floor Constructed?

  • Choose a suitable screed contractor who is the right fit for the job.
  • Select the appropriate screed floor type.
  • Produce floor screed mixture accordingly
  • Use appropriate and acceptable screed-applying process
  • Consider the right ways for floor screed protection

For which Projects Does Screed Work Best?

  • Although screed is used in commercial areas such as schools, hospitals, and airports, it can be used anywhere with internal flooring.
  • Screed is also an excellent choice for sound-proofing residential properties and other buildings exposed to noise transmission.
  • Moreover, those who want an industrial aesthetic or a decorative finish can paint or stamp it with a beautiful pattern.