Basics of Screeding for Concrete and Masonry

Screed or screeding in not a well-known term for those outside of the construction industry. It is usually the penultimate step in finishing flooring and commonly confused with concrete. As this article will discuss, there are notable differences in concrete and screed.

What is concrete screeding?

The chemistry between concrete and screed is similar but screed has finer use of aggregates (less than half of cement) and used to create a final finish before laying slabs, wood flooring etc. As it is not as hardwearing or durable as concrete, in some environments such as warehouses, the mix can be thicker and coarser.

What are the different types of screed?

Every project is unique, and the mix and consistency of screed varies depending on the floor requirements. Four of the commonly used types include the following:

Underfloor screed

The industry standard and used when screed is poured over heating pipes due to its ability to allow good heat flow.

Floating screed

Typically laid on a layer of insulation, where acoustic or thermal insulation is required. Usually on underfloor heating with a thickness of around 65mm-75mm.

Bonded screed

A strong agent or primer is needed to bond to the concrete/base especially in areas with heavy loads.

Unbonded screed

Laid on top of a membrane and a minimum of 50mm thick. As it is not bonded, settlement and any shrinkages can be minimised.

How do you screed concrete?

Using a specialist aluminium bar or two-by-four board and drawing it across the wet layer of concrete. The tool is pulled towards the worker in a sawing fashion, which smooths the surface whilst filling any gaps or hallows. Larger slabs may require two workers and the use of an aluminium bar for a more precise finish. Due to improvements in technology, a motorised screed could be used which significantly speeds up the process.

How do you screed a masonry base?

For bricks or pavers, it is recommended applying a layer of around 1 inch coarse bedding sand; as this is the last layer before the masonry product, keep it as smooth as possible. You can lay 1-inch PVC pipes across the area before application and this will improve the consistency whilst preventing deeper screeding. Once complete, gently remove the pipes and use any loose sand to fill any sinkages. A final screed will add to an even better finish.

Whatever your requirements are for screeding, an assistant is vital, as the tools are heavy and large.

Do you need some advice?

Working with a professional company like Haggar Construction can support you with all your flooring needs.

We pride ourselves on delivering smart, sustainable solutions for our clients’ construction projects, giving each project the time and focus it deserves and ensuring the highest quality outcomes. We are a family-run business with a huge amount of experience in the construction industry, working on large and small scale projects, but always with the highest level of commitment and professionalism.

We seek to add value to your project with our expert knowledge, forward-thinking approach and transparent service. If you’re looking for a hands-on team to help you with the utilities for your construction project, please do not hesitate to get in touch and one of our friendly team will be happy to help.