Types of Screed: Choosing the Right Base for Your Floor Finish

In Episode 12 of the ARDEX Answers Podcast, Monique Fenech is joined by Technical Services Advisor James Bradford to demystify the world of screeds—a critical but often overlooked component of floor preparation.

What is a Screed?

A screed is a layer of material, usually a mix of sand and cement or a proprietary blend, applied to a substrate to create a level surface for floor finishes such as tiles, vinyl, or carpet. Screeds help correct undulations, achieve desired falls in wet areas, and offer a sound, durable base.

Traditional vs Proprietary Screeds

James explains that traditional screeds—typically a 3:1 or 4:1 sand-cement mix—have been used for decades. They’re generally mixed and applied on-site and rely heavily on installer skill. On the other hand, proprietary screeds, like ARDEX A 38 or ARDEX A 48, come with engineered formulations for faster setting times and higher strength.

Key Benefits of Proprietary Screeds

Rapid drying times – Great for fast turnaround projects.
Higher compressive strength – More durable and resistant to cracking.
Predictable performance – Less variability than site-mixed options.
Shrinkage control – Reduced risk of curling and debonding.

Bonded, Unbonded & Floating Screeds

There are three main types of installation:

Bonded: Screed is adhered directly to the concrete slab. Suitable for thinner applications.
Unbonded: Screed sits over a slip membrane. Good for isolating movement or dealing with slabs prone to cracking.
Floating: Applied over insulation or acoustic mats. Used in energy-efficient builds or sound-sensitive environments.

Moisture Considerations

Screeds need to be dry before installing final finishes, especially resilient ones. Moisture meters or hygrometers can be used to determine moisture content. Proprietary screeds often dry much faster than traditional ones, speeding up project timelines.

When to Use What

If time is on your side and cost is a factor, traditional screeds can work—provided you’ve got skilled applicators. But in commercial projects, tight timelines, or areas where strength is critical, proprietary screeds are the go-to.

Need help choosing the right screed? Contact ARDEX Technical Services on 1800 224 070 or explore hands-on training at the ARDEX Academy near you.