Stairs with four winders: the four-winder turn

A winder is how a staircase turns a corner using tapered treads instead of a flat landing, which is covered in general on the winder stairs page. Most turns are made with three winders. A four-winder turn uses four, and although that sounds like a small change, it makes a real difference to how the stair feels and to how hard it is to build. It is worth understanding before you ask for one, because not every maker will make it.

Three winders is the default

The standard way to turn a stair through ninety degrees with winders is three tapered treads: the corner is divided into three, so each winder takes roughly a third of the turn. It is compact, it is well understood, and it is what most quarter-turn winder stairs are. It works, but because each of those three treads has to swing through a good chunk of the turn, the taper is fairly aggressive and the walking line round the inside can feel tight and quick.

What four winders changes

Put four treads into the turn instead of three and you share the same corner over more steps. Each tread is less sharply tapered, so the difference between the wide end and the narrow end is smaller, and the walking line round the turn is more even. In plain terms it climbs and turns more gently, feels less like a tight spin, and is easier and safer to walk, particularly coming down. That gentler, more even turn is the whole reason to want four winders. It is a way to soften a turn without giving up the length that a full landing would cost you.

Why it needs more room

Here is the catch, and it is the reason a four-winder is not just a free upgrade. Fit four treads into the same corner as three and each tread's going shrinks, because there are more of them sharing the same space. The going, the depth you actually put your foot on, cannot drop below what the rules allow, so to keep all four legal the turn has to be given more room: a bigger corner for the winders to fan out into. The winders turn around a boxed-out corner, what we call the winder box, and a four-winder simply needs a more generous one. So the trade-off is straightforward: a gentler turn in exchange for more floor space at the corner.

Why they are hard to get, not just hard to make

A four-winder is more work than a three, and it is skilled work. Four tapered treads all have to meet the winder box and each other cleanly, each with its going right on the walking line, which is more setting out and more that can go wrong than the standard three. It does not drop out of a standard staircase kit. Two things follow from that, and they are the real reason a four-winder is hard to get hold of. First, plenty of makers who can make one do not advertise the fact, so you will not see it on a price list or a web page. You have to ask directly, and know to ask. Second, you cannot design or order one through an online stair builder at all: the configurators only offer the standard turns, so a four-winder is simply not an option you can click. It is one of the clearest examples of why an online stair designer cannot replace talking to a real maker. If you want a four-winder, you need a maker you can have that conversation with, usually off the back of a survey.

The rules still apply

A four-winder is still a staircase, so it meets the same rules as any other. The going on each winder is measured along the walking line, not at the narrow end, and it has to be at least as deep as the going on a straight flight, with the narrow end no less than 50mm. The rise and pitch limits apply as normal, as on the rise, going and pitch page. What we deliberately do not do is quote exact corner sizes here, because a winder is a feasibility job worked out on the real space, not a figure typed into a box: whether four winders fit, and fit well, is something to check on a survey.