Installing an Exterior Spiral Staircase Kit

Exterior spiral staircase kits are great ways to access a balcony, upper level doorway or roof terrace, and most are within the reach of an experienced DIY’er if you want to build your own. There are several advantages with spiral staircase kits compared to ready-made spiral stairs, they are cost-effective, they can be easily transported, you don’t need a crane to get one into your back garden, and you can usually complete one in a day or two from start to finish.

Finishes

There are 2 types of finish we recommend, neither of which requires maintenance. Firstly and usually most economically, there is the hot dipped galvanized finish, where the treads and spindles are zinc plated at the factory. When new, a hot dipped galvanized spiral staircase will look quite bright and shiny - a bit too “bling” for some people, but give it a couple of years and the finish will weather to a more subtle “grey” which is actually very attractive. Good examples of this type of staircase are the Gamia Zinc, and the Civik Zinc. Both are very similar to look at, and are virtually identically priced - but the Gamia does comply with British Standards so if that’s important to you, go for the Gamia.

The second type of finish is galvanized but with a powder coated or electrophoretic finish over the top. This means that you get a colour coat finish, which being powder coated will be very tough, weather resistant and maintenance free. The finish is applied at the factory and never needs re-painting. A good example of this type of finish is available in the Neptune range of exterior spiral staircases.

Unless your idea of fun is painting a spiral staircase every year, we don’t recommend the cheap “exterior” stairs which use a spray painted finish - they never last and need re-painting often.

Start with good foundations

Never put an outdoor spiral staircase onto a wooden decking base or similar - the constant movement of the decking timber through the seasons will in turn cause movement in the staircase components, and eventually tiny cracks can appear in the finish which allows water to seep in and corrode the metal underneath. Always put the staircase on a solid base such as concrete, or on a patio. If installing to a patio slabbed area, to prevent slabs cracking ensure the slab on which the spiral staircase is resting is fully supported with mortar, or is on a level base of sand.

Assembling the kit

Follow the manufacturer's instructions for staircase assembly. Some manufacturers suggest sliding the upper landing and steps on to the center support post and then tipping the post up and into position. Or you can fix the centre post in place first, and then simply slide the components over the top of the post, ending with the landing platform at the top. It is crucial that the centre post is perfectly plumb, otherwise you will never get your treads level. At this point you can usually choose which way you want the staircase to rotate, clockwise or anticlockwise. Once decided, simply attach the balustrade spindles to each tread with the fixings provided.

Installing an exterior spiral staircase from a flat-pack kit is really straightforward, and with modern modular techniques of construction and kit design you can save a great deal of money too.