Bull Floats

Both tools are long, both are worked on a pole and both get called a float on site. They do different jobs at different moments, and confusing them produces a slab that looks right and does not hold its level.

A screed bar takes off surplus mix and sets the finished level. It is drawn along rails or across compacted concrete in a sawing motion, with material gathering ahead of the blade. Stiffness is what counts at this stage — a bar that sags in the middle transfers that sag straight into the floor.

A bull float follows immediately and removes nothing. Drawing the blade across the surface pushes aggregate below the mortar layer, evens out minor irregularities and brings the fat to the top. It is worked from the edge of the slab, on a pole, without stepping onto the concrete — which is the second reason, after sheer coverage, that the blade sits on a tube.

The practical consequence is that neither substitutes for the other. A bull float will not bring concrete to level, because the blade is too narrow and has nothing to bear on. A screed bar will not close a surface, because its edge gathers mortar instead of spreading it.

The choice between magnesium and aluminium comes down to timing. Magnesium goes on straight after screeding, while the surface is still wet and anything else would stick to it. Aluminium works a little later and is noticeably stiffer, which matters on the 1 524 and 1 829 mm blades — the longer the blade, the easier it sags in the middle, and that sag prints onto the floor as a hollow.

A wider blade means fewer passes but harder handling. At 915 mm the tool stays flat easily, even for one person; at 1 829 mm a few degrees of tilt has the float digging with one edge. That is why a bracket with angle adjustment is effectively compulsory at the larger widths.

The tool consists of three independent parts: the working blade, a bracket and a pole. What wears is the blade — poles and brackets last for years, so they are bought once.

The range covers complete tools ready to work, blades on their own for replacement (aluminium 1 220 × 203 mm, magnesium, manganese steel and Big Blue Float), and an Economic version with blade and bracket but no poles, for anyone who already has tubes from another tool.

Fittings complete the picture: a ⌀45 mm pole 1 830 mm long, fitting both floats and vibratory screeds, and a bracket with angle adjustment that allows the blade to be tilted mid-pass. Without it, at longer reach the blade holds one fixed angle and one edge takes more than the other. There is also a carry case, which matters for steel blades that do not tolerate being stored damp.

Three tools cover the screeding side, each for a different case. Magnesium screed bars of 2 000, 2 500 and 3 000 mm have double handles and are worked by two people. The aluminium straightedge with a built-in spirit level allows the level to be checked as the work goes on, without putting the tool down to reach for a level. The Bump Cutter at 3 000 and 3 500 mm cuts down local high spots, which usually only show up after the first pass.

The ⌀50,8 mm spreader bar for anhydrite screed is a separate tool altogether. Self-levelling compounds are spread differently from concrete: the material flows out on its own, and the tool's job is to distribute it evenly and release trapped air rather than take off surplus. Hence the round section instead of a flat blade — the bar is worked through the mix in a swaying motion, without gathering material ahead of it.

The previous stage, spreading the mix, is covered by concrete rakes. On larger areas screeding and compaction pass together to vibratory screeds, and finishing after the initial float is the work of hand trowels. The full order of stages is in concrete hand tools.