Automatic screed machines for liquid screed production and pumping

How does a liquid screed machine work?

A liquid screed machine works as a self-propelled production and pumping unit, combining dosing, mixing and delivery in a single automated cycle carried out directly on site, turning raw materials into a ready-to-pour mix without the need for a separate batching plant or pre-bagged product.

Raw materials (sand, binder, water and additives, or pre-blended binder depending on the configuration) are loaded into on-board compartments and conveyed into a dosing mixer, where quantities are set and controlled by an onboard computer rather than measured by hand. From there, the mix moves into a second, larger pumping mixer, which is hydraulically lowered to ground level during operation and raised again for transport. On Overmat systems, for example, this means a 300-litre dosing mixer feeding a 500 to 1,000-litre pumping mixer, with on-board binder tanks of 8 to 22 m³ and water tanks of 800 to 2,000 litres for full-day autonomy without refilling.

Throughout the cycle, a humidity probe reads the moisture content of the sand (or of the mix, depending on the system) in real time and automatically adjusts the water dosage, keeping the consistency uniform from the first batch to the last, regardless of how the raw materials vary through the day. This kind of precision is what allows well-designed systems to reach meaningful throughput: up to 10–12 m³/h of self-levelling screed and up to 25 m³/h of foam concrete on Overmat’s machines, for instance. The result is a fluid mix that can be pumped through hoses over long distances and heights, and that spreads and levels itself once poured, with no manual compaction required.

ALS-Series: the liquid screed machine built for professionals

For contractors working with cement or anhydrite-based liquid or self-levelling screeds mixed directly on site, Overmat offers the ALS Series , built around raw sand, binder, additives and water dosed and mixed directly on site, rather than a pre-blended mix loaded at the depot.

Because the formula is assembled on site rather than at the depot, the ALS-Series gives contractors full control over the mix design (cement type, additive ratios, fibre content) with custom recipes saved and pushed to the machine via the Mixer App, so the same precise formula can be recalled and repeated across batches and jobsites without depending on pre-blended material ordered in advance. Every dosage is computer-controlled, and a sand humidity probe reads moisture in real time and adjusts the water accordingly, keeping slump and workability consistent from the first load to the last — output reaches up to 12 m³/h of self-levelling screed.

A double binder silo version splits cement and filler into two separate compartments, which helps bring material costs down further on cement-based formulations.

The line spans five configurations, from a compact truck-mounted unit to a high-capacity semi-trailer version. Contractors looking for a screed machine for sale can compare the full model range and technical specifications on the ALS-Series product page.

Go to ALS-Series product page →

A-Series: Overmat’s machine built for pre-mixed liquid screeds

The A-Series is Overmat’s dedicated line for pre-mixed liquid screed production — a range of screed trucks built around a pre-blended binder loaded at the depot, rather than raw materials dosed on site. It’s designed for the mixing and pumping of pre-mixed liquid screed (self-levelling) and lightweight subfloors (foam concrete and polystyrene-based).

Because the binder arrives pre-blended, the A-Series trades on-site formula flexibility for speed and consistency: there’s no raw material dosing to calibrate on arrival, just a two-stage cycle where a 300-litre dosing screed mixer feeds a 600 to 1,000-litre pumping mixer, hydraulically lowered to ground level during operation. On-board binder tanks of 13 to 22 m³ and a 2,000-litre water tank give full-day autonomy without a depot run, while a patented humidity probe reads binder moisture in real time and adjusts water dosage to keep every batch certifiable.

Custom formulas are still stored and pushed to the machine via the Mixer App, which also tracks GPS location, machine status and production history remotely.

The line spans five configurations. The MSA 13.9A PTO stands out with dual independent binder compartments, letting operators switch between lightweight subfloor and pre-mixed liquid screed on the same day without reconfiguration. Contractors can compare the full range on the A-Series product page.

Go to A-Series product page →

Pre-mixed or mixed on site? Choosing the right liquid screed machine

The first real decision isn’t which Overmat series to pick, but where the mix gets assembled, and that choice drives everything else.

Going pre-mixed means less to manage on site: no raw material storage, no formula calibration before pumping, and a shorter learning curve for operators moving between jobs. It’s the better fit for contractors prioritising speed and consistency across multiple sites, or without space for bulk raw materials. This is the territory covered by the A-Series.

Mixing on site, by contrast, trades that simplicity for control: the formula can be adjusted batch by batch, cement type or additive ratios changed without reordering pre-blended material, and (on double binder silo versions) material costs cut further by dosing cement and filler separately. It suits contractors with the storage and logistics to handle bulk raw materials, and who value that level of mix control. This is what the ALS-Series is built for.

Either way, custom recipes can be saved and recalled via the Mixer App, so once a formula is set it doesn’t need to be re-calibrated on every job.

What’s Liquid Screed?

Liquid screed — also known as self-levelling screed or flowing screed — is a cement or anhydrite-based mixture with a fluid consistency that spreads and levels itself across a floor surface. It is widely used in the UK for both residential and commercial construction thanks to its speed of application, excellent thermal conductivity (ideal for underfloor heating systems), and superior surface finish compared to traditional sand-cement screeds.

Unlike conventional screeds, liquid screed can be pumped directly onto a floor and will self-level to a smooth, flat surface with minimal manual intervention. A single operator with the right liquid screed machine can lay up to 2,000 m² per day, dramatically reducing labour costs and project timelines.

FAQ – Frequently Asked Questions