Steps, Risers, Treads & Handrails
There is frequent confusion regarding steps and risers in the garden, as the dimensions and
recommendations commonly and erroneously espoused are those for indoor use.
Building Regulations Document M recommends an ideal height of between 150mm and
170mm for the riser – difference between one step height and another – with a maximum
height of 220mm. Crucially, the main recommendation is that all step heights should be equal,
and not vary more than a few millimetres between one step and the others.
Treads – the area to receive the foot step, should be no less than 280mm deep, although
450mm is recommended, for comfort and ease. Each tread should have the slab laid with a
slight fall towards the front edge to dispel any water from laying and causing problems with
ice in the winter.
Each tread should overhang the riser by approximately 25mm, and have a groove sawn into
the underside to act as a drip line along its length to prevent water from running down the face
of the risers, much the same as a window or door sill has a drip groove built into the profile
for the same reason.
Outdoor steps landings – those areas of deeper paving to allow people to pass each other –
must be at least 900mm deep.
Document K of the Building Regulations states that every flight of three steps or more, if they
are more than one metre wide, must have a handrail on both sides. If less than one metre wide,
they need only have one handrail. It is not necessary to have handrails for the bottom two steps.
These handrails must be between 900mm and 1000mm high, securely bolted into position.
Steps constructed free-hand by Alan Sargent to match an existing flight. As the property was Grade
2 Listed, and on private property, there was no need to follow guidelines regarding handrails.
