Anhydrite screeds are a popular choice in Essex and across the UK due to their high-quality finish, speedy installation, and efficiency on underfloor heating systems. But there is a concealed danger behind these advantages: ettringite formation. If left unchecked, this reaction can destroy the floor’s stability and lead to expensive repairs. At UK Screeds Ltd., we inform clients of the issue and how to avoid it happening in the first instance.
What Exactly Is Ettringite Formation?
Ettringite is a mineral that forms when anhydrite screed sulphates react with cement-bound materials, usually adhesives or levelling compounds. When water is present, this reaction is sped up, forming crystals that thrust upwards under the floor. These crystals, with time, can force coverings up, resulting in cracking, lifting, or total failure of the flooring system. Since it begins below ground level, the harm may be out of sight until it is too bad.
Why Moisture Is the Trigger
Dampness is the primary cause of ettringite formation. If a screed of anhydrite is not completely dry, it still contains water that can trigger the reaction when a cement-based product is added. This is why thorough moisture testing is essential prior to the installation of any coverings. Here at UK Screeds Ltd., we never proceed until anhydrite screed in Essex has been tested dry to the necessary standard. Omitting this stage jeopardises the long-term integrity of the floor as a whole.
Surface Preparation That Prevents Issues Early
Drying in isolation is not sufficient. Anhydrite screeds develop a surface laitance layer, which needs to be mechanically stripped away prior to application of adhesives or compounds. If neglected, the weak layer can hold in water and stop a proper bond. After laitance has been removed, primers are applied to achieve a stable barrier between the finishing products and the screed. Cumulatively, these procedures remove the circumstances in which ettringite may form.
How We Protect Projects in Essex
We have long-standing experience working with anhydrite screed in Essex, from domestic construction through to challenging commercial installations. Whatever the type of project, there is always a need for careful management of drying times, laitance removal, and sealing of surfaces. With a tried-and-tested procedure in place, we shield floors from the hidden risk of ettringite, allowing clients to be sure that their investment will pay off.
Contact Us to Build Floors That Last Ettringite development can be concealed, yet the harm caused by it is all too real. With proper preparation, it can be eliminated altogether. Leave it to UK Screeds Ltd. to provide installations that are expertly controlled at each stage. For professional advice and anhydrite screed installation in Essex, call our staff today.
nhancedigital@gmail.com
October 27, 2025
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At UK Screeds, we have been providing screeds and underfloor heating for building projects since 2002, so we are coming up to our 20th anniversary next year. Founded in Oxford, we have now expanded to 11 branches throughout England and Wales, and we are planning to open more new branches so that we cover the whole of the UK.
That is a fair enough question when you are constructing a new building, or even renovating an old one.
Let’s take a look at laying a new lawn. If you had just moved into a property, or had one built, and you wanted a beautiful green lawn with those lovely stripes, where you could sit all afternoon on a sunny day relaxing on a recliner, you would want that lawn flat.
When constructing any type of building, one of the most important factors is the floor. Certainly, the walls and roof are of vital importance, but equally important is the floor because that is going to take all the traffic, whether it is foot traffic, which it will be in most buildings, but can also be heavier, such as forklift trucks in a warehouse.
Liquid floor screeds have greatly increased in popularity over the last few years as they have so many advantages over the traditional sand and cement screeds. To begin with, they are very easy and quick to lay, as they are delivered to site ready mixed and simply pumped into position with a pump and long hose. Because they are in liquid form they flow into position and fill up any gaps or voids, which makes them particularly suitable when underfloor heating is being installed, since they will totally envelop the heating pipes. This makes for excellent thermal conductivity.
UK Screeds is the foremost provider of anhydrite screeds throughout England and Wales. Liquid anhydrite screed has so many advantages over traditional sand and cement screed, not the least of which is that it is so fast to lay. Our teams can lay up to 2,000 square feet in a day, and this is estimated to be up to 20 times faster than you could lay a sand and cement screed which has to be trowelled on by hand.
