Installing Stairs and Stair Parts

How to install Stairs, Handrails and Spindles

All about installing stairs, including:

How carpenters go about Installing stairs can vary from country to country. I think in the USA stairs are built on site in-situ, whereas in the UK staircases are pre built in a joinery shop and then delivered on site ready to be fitted in place. In Australia where i'm working at the moment stairs are mainly concrete and formwork carpenters put the shuttering together on site for the concrete to be poured into.

Sometimes the joinery shop will provide handrails and newel posts (if needed) already mortise and tenoned with the staircase ready to assemble. Some of the treads and risers may be cut but left out to fit after the installation in order to keep the weight of the staircase down during transportation and fitting.

There are several regulations that must be met when designing and building a staircase and its balustrade. The regulations differ in domestic construction than they do for commercial or public buildings. All the information in these pages is intended as a general guide to domestic staircase regulations.

Stair component diagram

There are several variations on the design like cut string and open tread for example, but the picture above shows the common terms and components that make up the structure of the staircase before the balustrade goes on. The balustrade is there for people to hold on to and stops them falling off the edge (where there's blame there's a claim..). It traditionally consists of newel posts, hand and base rails and spindles, although toughened glass has become fashionable nowadays too.

When designing a staircase the crucial measurement is the vertical one from 'floor to floor'. This is divided by the number of treads to give the height of each, and they must all be exactly the same. If not, people will trip up or down the stairs. The 'going' is the horizontal distance a person will walk as they scale the staircase. On a straight flight this is divided up to give the equal depth of each tread.

Installing stairs:

The first thing I do when I am installing a staircase is to check the floor to floor measurement, and the overall height of the staircase (multiply the height by the number of treads). It's important these too measurements are the same otherwise the only way to get it in is to adjust the height or fit it out of level, not ideal.

Plasterboarding / meshing the stairs

Once installed the underside of the staircase will need to be plasterboarded. There are building regulations that stipulate what type of board needs to be used depending on the use of the staircase, typically it should have at least 1/2 hours fire resistance. Sometimes the side of the stairs will be encased with studwork to build a cupboard or cloakroom, and the side can even be panelled to enhance the hallway. Panelling can be done with anything from MDF sheets and decorative beading or Oak, even tongue and groove boards.

Install the newel posts

Once the area is plastered, the newel posts can be installed into the bases. Handrails often need to finish at a wall, and in these instances a half newel needs to be fixed to the wall, to screw the handrail to.

Balustrade and nosing construction

The balustrade is made of a handrail and base rail that have a channel housed out in the middle the same width as the stair spindles being used, and they sit inside the channel. When you install the hand rail and base rail they are usually the same length (unless the stairs are cut string, when the spindles sit down on top of each tread).

When the balustrade is constructed on a gallery or landing, a nosing and apron lining will need to be installed. The apron lining is a flat piece of timber used to cover the trimming joists and for the ceiling underneath to stop into. The nosing is the same thickness as the flooring and is used because the edge of the flooring needs to be hidden when walking down the stairs. It has a bullnose/round over moulding that can easily be achieved with a router. The join between the flooring and the nosing is covered by the base rail that the spindles sit into.

Next, you calculate how many spindles you need, and use an infill strip of the same width cut in between the spindles to denote the spacing size and fill in the gaps. Standard spindle sizes are 32mm, 41mm and 50mm and there are different formulas to use to find out how many you need, depending on the size. Click here to find out how to get the spindle spacings perfect.

Installing stairs related pages