Garden decking cost guide

July 30, 2019

What is decking?

A deck is an external platform which connects to the house. A deck is often elevated and is now commonly used to describe the material (usually long timber boards) used for the flooring. Timber decks have become a popular alternative to the tiled patio in recent years. The classic British timber deck is accessed directly through patio doors and will be used for dining and relaxing, with steps down on to the garden and the deck itself surrounded by balustrading and handrails.

Decking cost calculator (materials and labour)

Decking Type Small House (24m2) Big House (80m2)
Non-elevated Softwood Deck no railing/stairs£1,100£4,600
Non-elevated Hardwood Deck no railing/stairs£1,650£6,900
Non-elevated Composite Deck no railing/stairs£2,800£9,500
Non-elevated Softwood Deck with railing/stairs £1,600£5,500
Non-elevated Hardwood Deck with railing/stairs£2,400£8,250
Non-elevated Composite Deck with railing/stairs£4,500£13,000
Elevated Softwood Deck with railing/stairs£2,200£6,500
Elevated Hardwood Deck with railing/stairs£ 3,300£9,800
Elevated Composite Deck with railing/stairs£5,600£19,040

Where is decking most effective?

Timber is a natural material, it is neutral from a style perspective and as a result can fit in well with almost any home, new or old. However, there are certain situations where a deck is a particularly good option. From a building perspective, the most significant advantage that decking has over patios is that it negates the need to level the subfloor before laying the finished floor. This is because the floor sits on raised joists that are secured into the ground adequately as mini piled foundations. This can save massive amounts of material cost and time. To take this benefit to its natural conclusion, on sloping gardens decks are by far the best way to create a level outside seating area connected to the home (and in some cases, the only practical solution).

decking bench

Pros and cons of decking

Pros

  • Quicker and simpler to install than a tiled patio
  • Cheaper
  • Looks excellent
  • Different laying options give flexibility
  • A perfect solution for sloping gardens

Cons

  • Timber decks require maintenance
  • Poorly maintained decks will crack, warp and become unusable
  • Can become very slippery if not maintained properly

Find Your Local Decking Installer

Recommended, vetted and monitored

How to build decking

Installing a basic deck to replace and sit on top of a simple existing patio is a job not beyond the abilities of a skilled DIYer. However, in most cases, homeowners are best served by using an experienced landscaping contractor.

A skilled contractor who has probably fitted dozens of decks doesn’t need you to check the quality of their work, but there are some things to look out for. The deck should sit at least 150mm below the damp proof course, and the decking boards should never actually touch the external walls of the house.

The supporting frame itself is obviously crucial – well supported and built to ensure dimensional stability. The use of joist hangers is essential, as is the use of noggins at 400 – 600mm spacings. Additionally, the frame itself should be supported every 500mm (usually with the insertion of timbers between the joist and the old patio on which it sits).

Suitable quality materials are essential. The timber should be pressure treated to maximise its chances of long-term durability and moisture resistance. The fixings should be exterior-grade, so they don’t stain or rust.

Lastly, a bit of preparation of the ground surface goes a long way to ensuring the deck looks as good after two years as after two days. Make sure your contractor puts down landscaping fabric and ideally some gravel on top to minimise any chance of weeds coming through.

Who should install decking?

Installing decking in most situations requires skill and experience to ensure long-term structural integrity but also a smart finish. As a result, it’s always best to use an experienced landscaping contractor. To find someone in your area, click here to find a tradesperson.

Do I need planning permission or building regulations for decking?

Adding decking is allowed under your Permitted Development Rights – meaning you won’t need to apply for planning permission. This applies to all decks that sit no more than 300mm above the ground level or are going to cover more than half of your garden.

Building regulations also apply to elevated decks and place requirements on balustrading, steps and the deck’s loading. Balustrading, for instance, needs to be 900mm high and 1100mm on steps, although there is no need for handrails on the bottom two steps. Spindles need to be positioned at less than 100mm spacings.

Which type of decking?

There has been considerable growth in the choice of different types of decking products available in recent years. The options for most homeowners are:

Softwood decking

The overwhelming majority of decking board is made of softwood timber, which is usually pine or spruce. It’s standard and widely available in stock at most suppliers. It’s the cheapest type of decking board – expect to pay £2 – £5/m2 for the boards. Pressure-treating the timber helps to protect it from decay, but it does require some intervention to keep it looking good and safe to use.

Hardwood decking

If you’re after something that looks a little different to the standard decking, then hardwoods are a good option. They can look naturally darker (such as oak) or more classic, such as oak, and can come in smoothed boarding. Hardwoods tend to have a greater density and therefore tend to be more dimensionally stable but will still need maintenance. Most hardwoods are imported, and it’s essential to check that the timber is sustainably sourced – but hardwoods are an excellent solution for those looking for a high-end, ‘designer’ decking solution. Hardwoods are expensive and while costs vary from type to type, expect to pay in the range of £5 – £10/m2 for the boards.

Composite decking

The great worries that people have about decking are that it is slippery in the winter, will decay over time and will eventually warp and crack. In recent years, several new products have come on to the market which aim to solve these problems and at the same time provide an attractive alternative design offer. The boards are usually a mix of (often recycled) plastics, sawdust and timber with a deep timber-effect grain on top. What you lose in ‘natural style’ you gain in resistance to moisture, decay, rot and warping. Composite boards often come with 25-year guarantees – a real statement of their long lifespan. Expect to pay £15 – £50/m2.

How to maintain decking

There are several enemies of the deck. UV from the sun will fade and dry out a timber deck, causing it to split, warp and crack. Too much water in the timber will cause it to decay and allow fungal infection and rot to take over – as will too much dirt. In addition to making your deck look terrible, it will also make it precariously slippy in winter and harsh to walk on in summer.

A maintenance plan aims to protect against these problems. There are three main options:

Decking stains – will weatherproof the deck and provide a finish that changes the appearance of the timber – for example a walnut stain. Stains change the colour of the deck itself, so be sure to test a sample spot first.

Decking oils – will provide a protective finish to the deck without changing the basic colour of the wood. Oils are perfect for enhancing a tired deck.

Decking paint – you can paint decks in the same way you’d paint other garden furniture and fences. Paints are inherently good at improving the appearance of tired or even slightly cracked wood, and some offer a non-slip coating.

While it’s tempting to stain your deck as soon as it’s down, most manufacturers recommend waiting 3-6 months before that first coat.

  • Was this Helpful?
  • YesNo

Search through our 36,000 recommended, vetted and monitored trades and service providers for free

Search now

More in this category

HomeownerNews

Guide to creating your smart home

Guide to creating your smart home Whether you’re keeping an eye on your carbon footprint or seeking the latest smart home solutions, having the ultimate smart home is easier than you think. There are a variety of options to suit every budget, from downloading a smart home app to a full smart home lighting system....

Continue reading
paint on new plaster

DecoratingHomeownerPainting

How to paint on new plaster for perfect results

Newly plastered walls can add a sleek and stylish element to your home. However, correctly painting fresh plaster can be somewhat challenging. This is why it is essential to take a look at a handful of steps so that this surface will retain all of its beauty for years to come. Although we always recommend...

Continue reading

HomeownerKitchen Fitting

Affordable kitchen ideas: the perks of second-hand and ex-display kitchen units

A kitchen is one of the most functional areas within any home. However, functionality and appearance often go hand in hand, and we often find ourselves seeking a sleeker, more modern looking kitchen. Are you considering upgrading your kitchen in the near future? The main issue for many homeowners is governed by a rather tight...

Continue reading