How to build decking steps uk: DIY Supplies & Accessories | DIY at B&Q

expert advice and tips |

Get the Homes & Gardens Newsletter

All the latest interior trends, expert advice and inspirational ideas, direct to your inbox!

Thank you for signing up to Homes & Gardens. You will receive a verification email shortly.

There was a problem. Please refresh the page and try again.

By submitting your information you agree to the Terms & Conditions and Privacy Policy and are aged 16 or over.

If you want to know how to build deck stairs, it’s likely that you’ve succumbed to the lure of this backyard feature. In the summer it seems that every outdoor space is punctuated by a well-placed, beautifully-designed deck. If you’ve decided to take on the task of building one yourself, you’ll know that it requires careful planning, a decent grasp of mathematics and confident DIY credentials.

Whilst there are many elements that go into building a deck, mastering how to build the deck stairs is possibly one of the most important. The stairs will be used by everyone accessing the garden below and they should complement the overall look of your deck.

We’ve asked the experts for their advice on how to build deck stairs, ensuring they meet basic safety standards and they look great too.

How to build deck stairs

Before we tell you how, these are the basics of what you will need to build decking steps. The easiest way to do so is with a kit, though you can of course start from scratch. 

You will need:

  • Timber: 2in x 6in and 2in x 12in 
  • Deck screws 
  • L-brackets 
  • Stair stringers
  • Stair treads
  • Chalk line 
  • Circular saw 
  • Drill 
  • Handsaw 
  • Spirit level 
  • Safety goggles

1. Calculate the deck stair measurements

‘Stairs require many calculations and an expert carpenter to fabricate them,’ explains Steve Vanadia, president of Vanco Construction.

The first thing you need to do is find where your stairs will end, or where the landing spot will be.

Lay a board from the top of your deck to the ground so you can start to calculate how high your stairs will be.

‘In short you divide the height from the top to the bottom by seven – this will allow for a very comfortable riser,’ says Steve.

‘Once you have that, you step off the stringer with a rafter square and allow for a 11in tread between each step,’ adds Steve. Alternately, use an online tool, which can help you work out all these measurements.

2. Assemble deck stairs

Start assembling your deck staircase by screwing the stair stringers to the bottom of the deck frame. Use L-brackets and long deck screws to attach the stringers to your deck.

Then you will need to cut the risers to fit the stringer. Set a riser against the edges of the stringers facing out and mark out guidelines where the riser needs to be trimmed to fit.

Use a circular saw to trim the riser, cutting along the guidelines until you cut through the whole board. Repeat the process until all of the risers have been cut to size. Then attach the risers with 3in deck screws. Finally, trim the treads and drill them into the staircase.

3. Add a handrail

Once you have finished your stairs, you will want to consider adding a handrail. James Bruteon, CEO of sustainable building materials supplier, Envirobuild advises you to check city codes and safety regulations before you buy a pre-made handrail.

‘There are standards to do with balustrade height, railings and loading capacity, as these could become real hazards’ explains James.

If you plan to buy a pre-made handrail, remember that they can always be cut down to size or adapted to make them work.

What is the formula for deck stairs?

The formula for deck stairs will help you work out the best number of risers to get from top to bottom. The formula is discovered by: measuring your deck height in inches and dividing it by seven. If you get a whole number, add a riser; if you get a decimal number, round it down.

What is a deck stair stringer?

A deck stair stringer refers to the housing on either side of a flight of stairs, into which the treads and risers are fixed. You can buy pre-cut stringers at your local DIY store and measure their height and length. 

If they are longer than you need, you can cut them to size. To cut a stringer to size, cut it from the bottom, it doesn’t matter if the bottom step is not as high as the others.

There are other parts of the staircase you will need to be aware of too. ‘Stair treads are the horizontal boards that you step on and the risers are the boards installed on the ends to cover the vertical spaces,’ confirms a spokesperson for online support service

 Building A Deck Staircase- Decking project 9

Gardenseeker Main

Decking Main Page ›

Raised Decking Project Intro ›

Raised Decking Project – 1 ›

Raised Decking 2 Setting Out ›

Raised Decking 3 Wall Fixings ›

Raised Decking 4 the Frame ›

Raised Decking 5 Support the Frame

Raised Decking 6 Decking ›

Raised Decking 7 Newels ›

Raised Decking 8 Balustrade ›

Raised Decking 9 Staircase Basic

Most raised decks need a set of steps or often a proper set
of decking stairs to get access to and from the deck to a lower
garden – or sometimes to a high level door – dependent upon
where the deck fits to the house. Some houses at the rear garden
have a floor level which is much higher than the garden – which
sometimes slopes away from the house.

The examples on this page are of very basic deck steps – quite easily
constructed using pre-made ‘stringers’ which will be sold at most
builder merchant or your normal deck timber supplier. The stringers are
pre-made, taking into account the rules and regulations for tread width
and riser height which will be a necessary consideration if building
controls are involved.

Decks can sometimes not be signed-off by a building control inspector
if the dimensions for treads and risers and also the angle of the steps
do not conform with building regulations. Basically the same criteria
are adopted as for full staircases in the house. There is no different
specification for deck staircases.

Simple single step from deck

Sometimes there is a single step required down from the deck to the
garden. This is easily achieved by building a box frame from the joist
timbers (6x2in – 150x50mm) and fixing deck boards to the surface. Aim
for 12in 30cm depth which is normally ok for two standard deck widths.
Even though it is just a simple single step, the box base will need to
be secured into the ground – NOT free standing. Over time there will be
wear under the fra,work, leading to an unstable, rocky step. 

Building a deck staircase – or even a few steps – is invariably the
most difficult part of the deck construction to get right. However small
the set of steps are, safety should be the first consideration. This
starts with proper construction giving a rigid project, and by ease of
use which will be defined by the building regulations. Even if you do
not need building control permission, it is as well to adhere to the
rules and regulation relating the staircase provision and Steps will or
should be accompanied by some type of handrail and again, there are
regulations that need to be adhered to for handrails.

the example images we have used simple pre-formed stair
stringers; by far the easiest way for a deck with a height
of up to 90cm (3ft). An added advantage of using deck
staircase stringers is that the staircase can be built
using your deck surface as a workbench (nice flat even
surface) or if you are not used to bending and kneeling
down yet (!) a moderate size set of steps can be built on
a sturdy workbench. You can also build the steps in-situ
after firstly securing the stringers to the deck and

Decks higher than 90cm – 3ft off the ground will need a different
approach to staircase building.

support reasons, the ground fixing is very important for you do not want
your steps sliding away from the deck over time. With good ground
support, the stringers can be simply resting against the decking fascia
with minimum fixings – just a few screws.

The support posts concreted into the ground will
also provide a good non-giving surface on which to base your newels –
assuming you are going to incorporate a balustrade or even a hand rail –
IMPORTANT even for a few steps down – or up.

standard deck staircase stringer will have been manufactured to take a
single 6in deck board as the riser, and two deck boards as the treads –
allowing for a slight nose over the front edge of the tread. This can be
clearly seen in the side view image of the steps. It is important not to
have too much overhang for the nose of the tread or tripping can be the

If your deckboards are not as wide as the standard
6in boards you should always have a full deckboard width at the tread
leading edge, and any in-fills of differing width can be situated in the
main depth of tread. Together with that, you will have to accommodate
the ‘give’ in narrower boards when used on the treads.
150x40mmdeckboards can normally be used with a 90cm span. The give extra
stability to the treads, it is a good idea to use an off-cut deck board
or joist under the tread as a central strengthening extra.


Staircase ready for fixing of the newels. The
overhanging treads will need to be cut in around the newel – or simply
trimmed off flush with the stringer surface. Overhang looks better and
can be further enhance by using a fascia deck board on both edges
attached to the stringer.

<<< Back to
page 8    To Decking Project

 <<<Back to Main Decking Project Page


Cordless Lawnmower

Multi-Purpose Compost

Westland Top Soil

Lawn and Turf Compost

Fish Food Tub

Pond Filter Pump

Weed Membrane



Learn – all aspects of lawn maintenance, how to build and maintain a pond, care and grow vegetables and fruit, fit for your table.

  • Lawns
  • Ponds
  • Vegetables
  • Fruit
  • Best Ten



Identify Weeds in The Garden – How to deal with weeds. Diseases and Pest which harm your garden and plants, learn how to prevent, deter and erradicate your garden problems.

  • Garden Pests
  • Garden Diseases
  • Garden Weeds

Garden Problems


Pruning Guide. Shrubs flower better with correct pruning. Many illustrations and examples of what to do – and when. Includes evergreens, roses, flowering shrubs, spring flowering shrubs and pruning for stem effect. This is our most viewed and comprehensive section,


Gardening Businesses

Gardening Businesses listed in the UK counties and USA states. County and State Listings of businesses involved in Garden supplies and services. If you wish to be added to the Directory, please send us your information. Having problems, use the search box


Metal grating steps from the manufacturer

Metal grating steps from the manufacturer

Grating steps are products based on welded or extruded grating mats. These parts of the overall ladder structure are surrounded on the sides by a surface with holes for attaching to the ladder itself. A module from such a flooring has a certain predetermined value – the width, length and height of the lattice cell. Thanks to the use of flooring as a horizontal tread, the weight of the entire staircase is reduced. Stair steps made of flooring have special requirements for the safety of personnel moving up and down engineering structures. Therefore, they have a special edging with increased anti-slip protection.

Our managers will help you to buy metal steps from grating, as well as to make an estimate and calculate the required amount of material. They will also offer a choice of material in accordance with the characteristics you need. Call 8 800 222 10 20 .

Ask for a discount price

Straight stair treads

Straight stair treads are the most popular and frequently used type of stair structure part. They are lattice-pressed, as well as made of welded cellular flooring. Their design and physical and technical features are used in the construction of all types of buildings and structures – residential, industrial, sports, etc. These metal structures are effectively used outdoors – these are fire escapes, transitions between individual buildings, various types of marches, etc.

Straight stair treads are manufactured using the same technology as pressed and welded metal gratings, either from mild steel with or without hot zinc coating, from stainless steel and aluminium.

Ladder steps made of mild steel have many advantages, which is why they are most popular in various fields of construction and industry. The lattice structure gives these steps high performance – they are resistant to constantly changing weather conditions – water does not accumulate on them, does not freeze into an ice crust, street dirt does not stick, etc. The step grating can be made anti-slip, which is also relevant in industrial premises with the risk of spilling water, oil and grease, and on stairs in rooms with intensive pedestrian movement of civil and technical personnel. The steel strips are serrated, which makes them safe to move even in rain, snow and icing. In addition, mild steel is durable, resistant to temperature extremes and corrosion. Therefore, such steps can serve for years and decades in open street spaces.

Grating spiral stairs

Spiral staircases are a constructive alternative to straight (flight) stairs, they are often used in industrial construction at sites where compactness and strength are required. Their special design allows in small rooms and narrow openings to make a convenient transition to the next level of the building.

Iron spiral staircases consist of three structural components – steps, railings and a central pillar. Metal steps in such screw structures have a special geometry – they are narrowed at one end and are attached around the central pillar at an angle of 30-45 °. This provides a short transition from one level to another. Spiral stairs have a special fastening – to the floor of the upper and to the floor of the lower level, and the stairs themselves are attached to the pole along the axial guide.

Spiral staircases are made from different types of metal. Those used on the streets are usually made of stainless steel, resistant to changing temperature and various atmospheric conditions. Steel screw steps are durable and resistant to loads. Their use is justified for access to objects located at a height – towers, tanks and cisterns both outdoors and indoors. Stainless steel is not afraid of corrosion, so its service life is practically unlimited.

Designs of spiral staircases require increased safety, including anti-slip. Therefore, steps, as a rule, are supplemented with a mandatory anti-slip coating – teeth cut on the carrier strip or edging on the outside of the step.

Today, spiral staircases are a popular part of a modern interior, adding not only beauty to the room, but also saving usable space.

Metal stairs

Metal is a versatile stair material that has long proven itself for its strength, excellent load-bearing capacity and durability. Its physical and technical properties make it possible to create stairs that are strong, reliable, light in weight, small in size, of any design complexity and design.

There are many types of metal stairs. These are classic stairs with straight flights and stairs, and spiral stairs.

Another type of stairs common in various premises is the turntable staircase. They are more often used in rooms with high ceilings to maintain the optimum angle of elevation. They are of two types – an L-shaped staircase (with a 90-degree turn) and a U-shaped staircase (with a 180-degree turn), and in both cases, the design has a turntable or winder steps.

Another type of metal staircase is a design with metal stringers – small ridges to which steps are attached.

There are metal ladders on the rails. This staircase design does not have a traditional frame, but consists of steps that are bolted to a load-bearing wall.