Traditional warehouse slabs are interrupted by construction joints, saw cuts, and crack control lines, all of which create weak points in forklift zones and racking areas. Jointless slab construction eliminates many of these problems by using fibre reinforcement and shrinkage control methods to pour large panels without sawn joints. But it requires precision in design, placement, and curing. This guide explains how to install a jointless warehouse floor that performs under load without cracking or curling.
Jointless slabs are designed to pour without saw cuts, using controlled shrinkage, not forced cracking. Start with a structural design based on fibre-reinforced concrete with a panel size of 25 m x 25 m or larger. Use a separation membrane to decouple the slab from the base and reduce restraint. Include construction day joints only where absolutely required, with dowels or leave-in-place formwork to manage load transfer.
Fibre reinforcement is key to jointless slab performance. Steel fibre mixes use 25–40 kg/m³, while macro synthetic fibres are dosed at 4–6 kg/m³ depending on design. Fibres distribute tensile stress evenly across the slab, replacing traditional mesh and helping the slab act monolithically. Choose fibres approved for structural reinforcement, not micro fibres used for surface control. Mixing must be consistent and verified by slump and dispersion checks on site.
Use a flat, compacted sub-base of crushed stone, blinded and levelled to tolerance. Apply a double-layer polyethylene membrane or other slip layer to allow the slab to shrink and move freely during curing. Any bonding or friction to the base causes restraint cracks. Laser check base tolerances and fix any dips or humps before pouring. Flatness of the base directly affects flatness of the finished slab.
Jointless slabs must be poured in one uninterrupted operation per bay. Use laser screeds for accurate level control and large-volume placement. Maintain concrete consistency with tight control of slump and mix delivery. Power float in sequence as the slab stiffens. Any delays or cold joints will compromise performance. Do not allow dry edges to form at construction day joints, these must be dowelled and finished cleanly.
Early shrinkage cracking is the biggest risk in jointless floors. Apply a curing membrane as soon as final trowelling is complete. Use a spray system to apply evenly and avoid dry spots. Curing agents prevent rapid moisture loss and allow full fibre activation and long-term strength gain. In hot or windy conditions, mist or cover the slab to reduce evaporation during the curing window.
Use FF/FL or TR34 flatness testing methods to confirm floor tolerance. Inspect construction joints and surface finish for defects. Jointless slabs are often polished or sealed after curing to reduce dusting and improve durability. Check that the slab performs as a monolithic unit and that no shrinkage cracks or delamination has occurred. Where needed, apply densifier or coating systems to complete the finish.
If you'd rather skip the stress and get a flawless concrete floor polished by professionals, we’ve got you covered. From precision prep to polished perfection, we handle it all.
Get in touch today for a no-obligation quote on polished concrete flooring:
Or fill in the form below and we’ll get back to you with honest advice and a competitive quote.