Best Practice on Screed and Concrete Pours – Tips from Industry Pros

Getting a high-quality finish on screed and concrete pours is often the difference between a floor that performs reliably for years and one that causes problems from day one. So, we decided to gather some practical insights on getting the best finish from UK contractors who work with screed and concrete every day. Their combined experience shows how preparation, teamwork, material choice and on-site technique all shape the final result – check out their top tips below!

Preparing the site properly before screeding

Multiple contractors we asked stressed that the quality of the finish is largely decided before any screed is poured. Southern Screed were clear on this point: “We cannot stress enough how important it is to ensure the preparation work has been carried out correctly prior to the screed installation.” They explained that incorrect placement of the slip membrane could have a serious detrimental effect on the screed, and that their team will not go ahead with a pour if preparation hasn’t been completed to a suitable standard.

Good preparation means perimeter insulation is tucked neatly behind the slip membrane, with polythene cut, folded and taped tightly into corners. The Southern Screed team also highlighted the importance of ensuring underfloor heating pipework is clipped at close centres and that polythene is laid neatly at the perimeters to allow the screed to form a clean ninety-degree edge. Provisions should also be made to protect the screed from direct sunlight during and after installation to avoid rapid moisture loss – you can find more tips on preparing for a screed pour in this blog post.

Somerset Screed also highlighted the importance of membrane choice and installation. They recommended a 1200-gauge membrane to reduce the risk of tearing while trades move in and out: “Always leave the membrane slightly loose around the edges when it’s taped to the wall. When the screed flows in, it will pull the membrane tight and prevent hollow points around the perimeter.”

Setting levels

Accurate levelling before the pour begins was a recurring theme. Joe Baker from Second City Screed explained how important it is to establish levels early. “We use levelling tripods to set the screed level to the datum to ensure a flat and level install of flowing screed.” Using a laser set to the finished floor level creates consistent reference points across the whole area and reduces the risk of ending up with an uneven floor surface later on.

Dappling techniques for flowing screed

Dappling was repeatedly described as essential rather than optional. Joe Baker explained that it is about controlled manipulation of the screed, not just flattening it. “When we give the screed a dapple, it’s a bit of manipulation on the floor to get the air bubbles up to the top and that gives you a lovely flat smooth finish.” His team always dapples twice, once to release trapped air and again to refine the surface.

Somerset Screed echoed this view, noting that even “self-levelling” screeds require dappling. “Although liquid screed is self-levelling, the process of dappling further agitates the mixture and perfects the finish.” They also stressed the value of teamwork during this stage. “Whilst one of us is pouring, the other one is dappling the screed… once we are both happy with the levels, we remove the pipeline and begin the more precise dappling stage to create the perfectly smooth glass like finish.”

Controlling the mix and the pour

Before pumping screed, Joe and his team at Second City Screed carry out a slump test to check viscosity and avoid guesswork. Adjustments are made carefully before the pour begins. During placement, the pipe is kept moving. As Joe puts it, “Yes, I know it’s liquid but it doesn’t find its own level all the way!” so active control remains essential.

Best practice on concrete pours

The same attention to levels applies to concrete slabs, and Joe described Second City Screed’s process clearly. “After pouring C30 concrete into the floor slab, we rake it around to the desired depth. Then we check the level with a laser setup and receiver set to the datum.” The slab is then tamped with dapple bars to ensure it is flat and level across the full area.

He also highlighted curing as a step that directly affects surface durability. In fact, Joe recommends using a sprayer, such as the Chapin 1949, dedicated only to curing agents. “It avoids cross contamination and gives a much more consistent application,” provided the sprayer is cleaned properly and the nozzle kept clear.

Choosing the right screed material

Material choice can also influence finish quality and programme. Southern Screed shared why they often specify Cemfloor liquid screeds over traditional sand and cement screeds. Cemfloor is a cement-based flowing screed with added binder and superplasticiser to improve performance. It dries far quicker than traditional screed, often within 21 to 28 days depending on depth, compared with traditional sand and cement screeds which typically dry at around one millimetre per day.

Liquid screeds like Cemfloor, Gyvlon or Highflow also don’t require reinforcement and can be laid at thinner depths, making them suitable where build up height is limited. They work particularly well with underfloor heating, fully encapsulating pipes and allowing heat to pass through a smaller depth of screed, and can also be force dried without the risk of cracking. On larger projects, liquid screeds allow significantly greater daily coverage and on-site batching helps reduce waste.

Bringing it all together

Across all these insights, one message stands out. High quality concrete and screed finishes come from careful preparation, informed material choices and attention at every stage of the pour. Tools support good practice, but it is the experience and decisions made on site that ultimately define the result.

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