1-3 Screed Explained

I’m Andy Parkin, Managing Director of the Multi-Award Winning Floor Screed  I’m here to talk about 1-3 Screed.

Site Batched or Readymixed?

1-3 Screed can be supplied pre-mixed directly to the site, however, the majority is site mixed. Site mixing affords many benefits and provides you with a fair amount of leverage and control, while also giving you the chance to use a fresh mixture throughout the day.

1-3 Screed Materials

1-3 Screed is a mixture of cement and sharp sand, mixed at this ratio it provides a heavy-duty screed suitable for category A floors (heavy-duty commercial use). The screed is stronger than its 1-4 counterpart since it has a higher percentage of cement.  Additional coarse aggregate can be added to the mix to provide even greater strength and durability.  10mm single size if ideal for this purpose and would replace some of the sharp sand Floor Screed.

Which Type of Construction?

The 1-3 Screed can be bonded directly to the concrete substrate, with the introduction of a bonding agent or slurry mix.  The resultant strength of the screed is dependent on the substrate, and it needs to be sound and free from contaminants.

Unbonded screed as the name suggests are not bonded directly to the concrete base which means the minimum depth should increase from 40mm with bonded, to 50mm for unbonded.  Usual the screed is laid onto a membrane with this application.

Floating 1-3 screeds are used in both commercial and domestic projects, especially those with underfloor heating systems, laid on insulation. The depth of the screed needs to increase to allow for the increased movement of the screed, and the minimum depth would 65mm domestic and 75mm commercial.

It is recommended that 1-3 Screeds are mixed with polypropylene fibres to help minimise and manage shrinkage cracking.

I hope this helps with your “1-3 Screed” questions.  Do get in touch for more information.