Learn how to screed freshly placed concrete so the slab reaches the intended level, thickness and fall before the later finishing stages begin. This guide explains preparation, screed boards, wet-edge technique, strike-off passes, low-spot correction, floating, edges and joints, weather considerations, curing and common mistakes in a practical step-by-step format.
Screedingโoften called striking offโis the operation that brings freshly placed concrete to the intended elevation by moving a straight edge or mechanical screed across reference points such as forms or screed rails.
Screeding happens after concrete has been placed and roughly distributed, but before most final finishing operations. The screed removes excess concrete from high areas and helps move material into low areas. Its job is not to create the final polished, broomed or trowelled texture. Its job is to establish the correct plane of the slab so later floating and finishing start from a consistent surface.
A good screeding pass depends on preparation completed before the concrete truck arrives. Formwork must be secure, finished levels must be known, falls must be set, reinforcement and penetrations must be in their required positions, and the crew must know where concrete will be placed and how the screed will travel. Once fresh concrete is being discharged, there is much less time to solve basic layout problems.
Rest the screed on reliable guides, keep the edge engaged with the reference level and move steadily while a small roll of workable concrete stays just ahead of the screed.
The exact tool set depends on slab size, access, crew size, finish specification and whether the work is hand screeded or mechanically screeded.
A straight timber, aluminium or purpose-made screed long enough to bridge the guides without excessive flex.
Used to distribute fresh concrete and move material into low areas without dragging reinforcement out of position.
Used after strike-off at the appropriate time to smooth ridges and help prepare the surface for later finishing.
Used before and during placement to confirm forms, screed rails, elevations and required falls.
Used when the specified finish requires formed edges and tooled joints after the surface reaches the proper stage.
Useful near edges, penetrations and small areas that a long-handled float cannot reach cleanly.
Mechanical strike-off equipment used on suitable flatwork where the crew, formwork and concrete are set up for it.
Concrete-resistant gloves, suitable footwear, eye protection and the controls required by the actual task and workplace.
Screeding can only be as accurate as the reference levels supporting it. Check the top of the forms, screed rails or other approved guides against the required finished surface. Where a slab needs drainage, confirm the direction and amount of fall before concrete placement. Do not try to invent the fall while the screed board is already moving through wet concrete.
Forms must be able to resist the pressure and movement associated with concrete placement and screeding. If a form bows, settles or moves outward, the finished edge and level can move with it. Secure forms and stakes before the pour and recheck critical dimensions after heavy traffic or pump setup near the slab.
The base, reinforcement, vapour barrier, services and penetrations should already be ready for the pour. Screeding is not the time to discover reinforcement sitting at the wrong level or a service penetration missing from the slab. Follow the project documents for support, cover and placement details.
Decide where concrete will enter the slab, how the crew will distribute it, where the screed begins and how workers will avoid becoming trapped behind freshly levelled concrete. Large placements require a coordinated sequence so the wet edge remains workable and the crew can keep up with discharge.
Screeding often needs at least two people on a manual board, plus workers moving concrete ahead of the screed. The required crew grows with slab width, concrete delivery rate and complexity. Tool shortages during placement can create delays exactly when the concrete is becoming less workable.
The sequence below describes a conventional hand-screeding workflow for flatwork. Actual project procedures may differ with equipment, slab design and specification.
Before concrete reaches the screeding area, confirm the forms or screed rails are at the intended finished elevation and fall. Any error in the guide will be transferred to the fresh surface.
Distribute concrete across the working bay so the screed has enough material to strike off. Avoid leaving deep holes that the screed cannot fill or huge piles that require aggressive pushing. The goal is a reasonably even, slightly overfilled working surface.
Place the straight screed so each end has reliable bearing on the forms or rails. Keep the board controlled and aligned. If one end lifts from its guide, the finished level can change immediately.
Pull or advance the screed while moving it slightly side to side. The motion helps the board cut through high spots rather than simply bulldozing concrete forward. Keep the movement controlled; violent rocking can create hollows and disturb the surface.
A modest roll of workable concrete in front of the screed helps feed minor low spots. If the roll disappears, add material ahead of the board. If it becomes a large heap, rake or shovel some concrete away so the screed is not fighting an unnecessary load.
The people controlling the board should keep each end in contact with the guides. A consistent pulling speed and coordinated side-to-side motion produce a more even strike-off than one person racing ahead of the other.
After a pass, look for obvious depressions, torn areas or places where the screed left insufficient material. Add fresh concrete to those areas rather than trying to smear cement paste across the surface to hide the defect.
Run the screed over corrected low spots while the concrete remains workable. Use enough passes to establish level, but avoid repeatedly dragging the board over the same area without a reason. Excessive surface manipulation can increase paste and reduce control.
Coordinate concrete delivery and screeding so the next area is placed before the previous working edge becomes too stiff to integrate properly. Large delays can create visible transitions and make the next strike-off much harder.
Once the surface has been struck off, the next operation is commonly floating rather than more screeding. CCAA's current Guide to Concrete Construction treats handling and placing, compaction, finishing flatwork and curing as separate but connected site-practice stages. Follow the finishing sequence and timing appropriate to the specified surface.
Screeding to a fall uses the same strike-off principles as a level slab, but the guides are intentionally set at different elevations so the finished plane slopes toward the required drainage point. The key is to establish the fall before placement rather than trying to create it by pressing harder on one side of the board.
Confirm the high and low sides with a laser, level, stringline or other project-approved reference. For a simple one-way fall, the form edges may provide the screed plane. For more complex drainage around pits or multiple falls, intermediate screed rails, pins or other control methods may be required.
Crews sometimes instinctively try to make a surface visually level while screeding. If drainage has been designed into the slab, that instinct can remove the intended slope. Keep the screed riding on the correct reference levels and verify the finished plane as work progresses.
Areas falling toward a drain are often better handled in smaller planes or bays rather than one long straight strike-off. The appropriate method depends on the slab geometry and finish specification. Set the drain rim and surrounding guides correctly before concrete placement.
Screeding is only one step in concrete flatwork finishing. After strike-off, the surface may be bull floated, hand floated, edged, jointed, trowelled or textured depending on the specified finish. The timing matters because fresh concrete changes rapidly from a plastic material into a setting surface.
Bull floating is commonly used after screeding to flatten small ridges and help prepare the surface for later operations. The float should not be used as a substitute for accurate screeding. If the slab has major highs and lows, correct them at the strike-off stage rather than expecting the float to reshape the entire slab.
Avoid finishing practices that trap or work visible bleed water back into the surface. Timing should respond to the actual concrete and conditions. Surface operations performed too early can damage the finish, while waiting too long can make the concrete difficult to work.
Edging and jointing are separate finishing operations. Their timing and layout depend on the slab, finish and project requirements. Do not let attention to the centre of the slab distract from maintaining the intended edge level next to forms.
Many screeding problems start before the board touches the concrete. Preparation, concrete distribution and crew coordination matter as much as the strike-off motion.
A large mound creates excessive resistance and encourages the crew to lift or twist the board. Distribute the material more evenly and maintain only the amount required to feed low areas.
If there is no material ahead of the screed, low areas stay low. Add fresh concrete in front of the board and strike off again. Do not simply pull paste across the depression.
Losing contact with the guide changes elevation. It can create a ridge, dip or tilted surface. Coordination between operators is essential on a manual screed.
Perfect screeding over forms set to the wrong level still creates the wrong slab. Confirm the reference system before the pour.
Screeding establishes level. Later operations create the specified finish. Excessive repeated striking can overwork the surface without replacing proper floating, edging, jointing, texturing and curing.
Temperature, wind, humidity and direct sun can change how quickly the surface loses moisture and how fast the concrete becomes harder to work. CCAA's Guide to Concrete Construction includes dedicated material on hot- and cold-weather concreting as part of concrete site practices. The practical implication for screeding is that the crew and delivery sequence must match the conditions rather than relying on one fixed timetable. ๎cite๎turn155650search3๎
In hot or drying conditions, organise labour, screeding equipment, finishing tools and curing materials before placement begins. Delays can become more costly because the working time may feel shorter. Shade, wind management and other project-approved controls may be appropriate depending on conditions and specification.
Cool weather can slow setting, so later finishing stages may take longer to become ready. Do not force the finishing sequence simply because a usual clock time has passed. Judge the actual concrete and follow the project procedure.
Rain can affect fresh surface quality and finishing. Check the forecast before a major pour and have the project-approved weather plan ready. Do not treat rainwater on the slab as a substitute for controlled concrete mix water.
Screeding involves wet concrete, repetitive manual handling, awkward postures, moving equipment and a live construction environment. Use the PPE and work methods required by the site risk assessment and product safety information. Fresh cementitious material can be hazardous to skin and eyes, so workers should avoid unprotected contact and follow the applicable safety data.
Silica dust is mainly a concern when hardened concrete or other silica-containing materials are mechanically disturbed rather than during the wet screeding pass itself. Safe Work Australia identifies concrete cutting, grinding, drilling, jackhammering and chiselling among activities that can generate respirable crystalline silica. Those later activities require their own risk controls; do not assume screeding PPE alone covers them. ๎cite๎turn155650search0๎turn155650search6๎
Long screed boards can be heavy, especially when concrete builds up on them. Use enough people for the equipment and working width. Avoid uncontrolled twisting while pulling the screed.
Pump hoses, reinforcement, form stakes, tools and wet concrete can create difficult footing conditions. Plan worker access and the direction of the screeding operation before discharge begins.
Follow the manufacturer's operating instructions, guarding, electrical or fuel requirements and site controls for powered screeding equipment. Mechanical equipment does not remove the need for correct form levels or trained operators.
Screeding and finishing create the surface, but curing supports the concrete after the surface work is complete. CCAA's 2020 Guide to Concrete Construction places curing in its own concrete site-practices section immediately alongside handling, placing, compaction, finishing, surface control and cracking topics. That reflects curing's importance as a separate construction operation rather than an optional cosmetic step. ๎cite๎turn155650search3๎
Use the curing method and duration required by the project specification and applicable product or construction guidance. The correct start time depends on the finish and curing system. Prepare curing materials before the pour so the crew is not searching for them after the slab has already been finished.
Curing methods can include project-approved water retention, coverings or curing compounds. Each method has practical requirements, and some later coatings or flooring systems may have compatibility considerations. Follow the project documentation rather than improvising after the surface has set.
Use this list as a pre-pour and during-pour reminder. It does not replace project drawings, specifications or competent site supervision.
Good hand screeding is less about brute force and more about keeping the board controlled. The operators should maintain contact with the reference guides while using a short side-to-side or sawing action as the screed advances. That movement helps the leading edge cut through local highs while the small roll of concrete ahead supplies nearby lows.
The screed should not bounce violently up and down. Excessive lifting can create waves in the surface, while excessive downward pressure can dig into fresh concrete and change the intended elevation. Keep the board working on the guides and let the straight edge define the plane.
Manual screeds are commonly pulled toward the operators as the concrete is struck off, but the actual direction depends on the setup and equipment. What matters is maintaining a predictable working edge, a clear route for the crew and reliable contact with the forms or screed rails.
Concrete build-up can change the screed edge and add unnecessary weight. Clean the working edge as required during the pour without disrupting the slab. A clean, straight contact edge gives a more consistent strike-off than a board carrying hardened or lumpy material.
A very wide bay can be difficult to hand screed accurately because the board becomes heavy and may flex. Larger slabs are often divided into manageable working widths or use mechanical equipment. The correct method depends on slab dimensions, formwork and the contractor's equipment.
A well-screeded surface should be close to the required finished plane before floating begins. It should not contain obvious deep hollows, large ridges or abrupt steps between passes. Required falls should remain intact, and the surface should provide a consistent base for the next finishing operation.
Fresh concrete can look uneven because of aggregate, paste and surface moisture even when the general elevation is acceptable. Use the project reference method to check critical levels and falls rather than relying only on visual appearance.
Where two screeding passes meet, avoid leaving a ridge or trench. The next pass should tie cleanly into the previous work while the concrete remains workable. A long delay can make that transition harder to blend.
A low spot is a volume problem. Correct it with concrete while the material is workable instead of dragging a thin layer of paste across the depression. Surface paste alone does not replace the missing body of concrete beneath it.
Larger slabs often require more planning around bays, internal beams, penetrations and crew access. Screeding may be combined with mechanical equipment and multiple level references. The principle remains the same: establish the correct concrete plane before later finishing.
Driveways may include crossfall, transitions, thickened edges or changes in grade. Confirm those levels before placement and avoid unintentionally flattening drainage while striking off. Vehicle crossings or work near a public road reserve can also involve separate local requirements.
Narrow paths are often suitable for a straightforward hand screed spanning the side forms. Curved paths can require shorter screeds or frequent changes in working direction. Check that the forms maintain the intended crossfall and longitudinal slope.
Outdoor areas commonly need drainage away from buildings or toward designated points. Around pools and drains, multiple planes may meet. Treat each plane as a deliberate screeding surface rather than trying to create every fall with one continuous flat board.
Use these related pages for quantity planning and other flatwork stages. This screeding page remains a guide only.
Common questions about screed boards, strike-off motion, timing, wet edges, floating, slope and surface correction.
Screeding is the strike-off operation that brings freshly placed concrete to the intended elevation by moving a straight edge or mechanical screed across forms, rails or other level references.
Screeding comes first. Bull floating is generally a later operation used after the slab has been struck off to help smooth ridges and prepare the surface for subsequent finishing.
Maintain a manageable roll rather than a huge pile. There should be enough workable concrete to feed low spots without forcing operators to lift or twist the screed against excessive material.
Very small widths may sometimes be handled by one experienced person, but conventional hand screeding commonly benefits from two operators controlling the ends while other workers distribute concrete ahead of the board.
A straight timber board can be used for suitable small work, but it must be straight and stiff enough to span the guides without excessive deflection. Aluminium or purpose-made screeds can be lighter and more dimensionally stable.
The bow can be transferred to the slab surface, creating an unwanted high or low profile. Check the screeding edge before placement begins.
Add fresh workable concrete to the low area and strike it off again. Avoid trying to hide a substantial low spot by dragging only surface paste across it.
Set the forms, rails or reference points to the intended slope before placement, then keep the screed riding on those guides as you strike off the surface.
Do not make unplanned changes to concrete water content simply to improve workability. Use the specified concrete and coordinate workability requirements with the supplier and project team.
Screeding establishes the main surface elevation by striking off excess concrete. Floating is a later finishing operation used to smooth the struck-off surface and prepare it for subsequent finishing.
The wet edge is the workable boundary between concrete already being struck off and the next fresh placement. Coordinating placement helps keep that boundary workable and reduces difficult transitions.
Yes, screeding does not replace curing. Curing occurs after the finishing sequence and should follow the method and timing required by the project specification and applicable guidance.
No. The screed normally follows the reference provided by the forms or rails. If those guides are wrong, the surface can be wrong even when the strike-off technique is good.
Use current technical guidance, project specifications and workplace safety requirements alongside practical screeding advice.
Australian concrete guidance covering handling and placing, compaction, finishing concrete flatwork, curing, cracking control and hot/cold-weather concreting.
View CCAA GuideCCAA guide focused on the design, specification and achievement of concrete flatwork finishes.
View Flatwork GuideCurrent guidance on respirable crystalline silica hazards from cutting, drilling, grinding, jackhammering and other work on concrete and masonry.
Read Silica GuidanceUse the actual drawings, concrete specification, safety data sheets, equipment instructions and site procedures for the work being performed.