Getting Stone Right

Stone has seen a resurgence in popularity thanks to its inherent characteristics of quality and durability, but also its ability to give an immediate identity to homes in a particular region.

From the rich yellow limestone of the Cotswolds to Glasgow’s red sandstone, regional stone anchors projects to their locale and gives homes a distinctive character that ties them to the history of the area.

How to Choose the Right Stone

Modern construction techniques allow stone to be used more creatively than in past years. In many ways, it has been re-invented as a cladding material rather than being seen only as a loadbearing material. This means it is now increasingly used on both traditional and contemporary-style projects.

Stuart Archer used reclaimed granite on his Highland home to match the existing barns on site. The result is a contemporary take on a traditional croft, using the granite and Scottish larch, along with large expanses of frameless glazing

The choice of stone, its detailing and even the mortar will therefore directly affect the style of the house you are creating. So there are some key decisions you and your team (your architect and perhaps builder) will need to make.

Stone Type 

Do you opt for a regional stone to match the area or pick a contrasting option to make a statement? If you are buying from out of your area expect the costs to rise.

Size 

Historically, larger sizes were used on the grander houses and often on the estate houses to match the main manor house. Typically, the larger the stone module the greater the price.

Finish

Different finishes can affect the overall look. A popular option is dressed stone, which gives a precise, highly uniform finish. Other effects include sand-blasted or riven.

Laying Pattern 

Think about how the stone will be laid. Options include:

  • coursed
  • uncoursed
  • random rubble
  • dry stone
  • flint pattern

Does the building demand a coursed stone like a Georgian house, or is the aesthetic more agricultural? In this latter case, an honest uncoursed or rubble façade would be more suitable.

These two finishes can be cheaper and more appropriate to a more basic architectural form, but they can work equally well on modern buildings when contrasting with a sharper modern material.

Mortar Choice

Random rubble will have more visible mortar to cover the irregularity of the stone compared to dressed stone. A dry stone wall will ideally have no mortar (or hide the fact it does with skilfully placed mortar at the back of the construction).

Don’t forget to think about the colour, too. Pick with real care and take your time to trial some — or live with the error for a long time.

When renovating a listed building, the local authority conservation officer will impose conditions on what stone can be used — this will usually be to match the existing. 

It’s often the architect who decides on the type, size and mortar colour. Of course, sample panels are there so everyone involved will be able to give their opinion and tweak the final design. These panels are usually a necessity of planning too, and the planners will often insist on signing off on the materials used.

Laying Patterns

(Left to right) Ragwork, Slate Walling: Rough thin stones laid horizontally, perfect for naturally thin slate; Uncoursed Ashlar: Squarely dressed stones laid in different sizes in random order; Polygonal Uncoursed: Stones dressed to have many sides, laid in an irregular pattern; Coursed Ashlar: Squarely dressed stones, typically laid coursed for a more uniform look; Rubble Walls: Random sized and shaped stones produce a random pattern; often used on cottages

How to Use Stone

Solid wall construction Over a century ago, stone would have been used in a solid wall construction as the loadbearing wall. A stonemason would have carefully selected the best stones for the external face of the building, with the cheap stone and rubble used inside the solid wall.

Outer stone leaf As buildings developed cavities from the Edwardian period onwards, the use of stone developed in a manner similar to brick construction, with metal ties used to tie the outer stone leaf to the inner leaf of blockwork.

Stone cladding With modern construction methods, such as SIPs, steel and timber frame buildings, stone remains popular, but as an outer skin or cladding. When used this way, the designer needs to think about how to connect this heavy material with the lightweight structural system.

Andrew and Toni Leese contracted package build company Potton to build the timber frame for their new home in the Cotswolds. They opted for a Cotswold stone-clad exterior to meet planning conditions

One option is an off-site system in which the stone is fixed, in a factory, to concrete panels. These are then delivered to site and bolted onto a steel frame using a variety of fixing systems.

Some of the new systems have a full stone panel or stone tile bonded to a granite backing, allowing the stone face to be a larger size tile. These are then fixed on metal carrier/hanging rails hidden behind the stone tile, which can be fixed to the main structural system of the house.

It’s not always a cheap option: the systems start from £120 for the stone and £50+ for the structural system.

It’s generally specified when there are large areas to cover, or on difficult sites where the speed of erection that comes with this method is a major bonus.

Remember, though the upfront costs might be high, the labour cost is massively reduced as the site work simply involves bolting it all together.

How Much Does Stone Cost?

This material is expensive. Even with a shortage of skilled bricklayers, the cost of brick will still be about half that of stone. When estimating the costs,you have to factor in the price of the raw material and the skilled labour of laying it.

The labour costs reflect the time-consuming nature of laying this material, and it’s a false economy to spend on a beautiful product and cut costs by getting a non-expert to lay it.

Each stonemason has a slightly different style, adding to the texture of the building appearance, and their skill, expertise and knowledge will benefit a project.

Each area of the country has companies that specialise in their stone of the local vernacular so take the time to find them — it’s worth it.

  • Limestone: Putting up a limestone wall will cost around £150/m2, which is slightly more expensive than sandstone.
  • Slate: A slate wall may cost closer to £200/m2, and will be even more expensive if you’re further away from its natural habitat in places like the Lakes. This is true of any stone, so it usually pays to stick to materials common in your region.
  • Combined with timber, brick or render: To save costs, it may be worth combining stone with brick, timber or render. Timber has always combined well with stone and continues to look good — cedar cladding, for example, is around £20-£50/m2. Render (£80-£140/m2) can also be used to give a sharp contrast and is used on many contemporary buildings. Obviously, the amount of stone can be reduced to feature panels, as render and cedar is cheaper than the stone.

How to Match Materials

If you are looking to match a stone, for example when renovating or building an extension, it can be difficult. There are several options:

  • Speak to local stone suppliers and quarries about what is available
  • Speak to the planners and conservation officers. If they are stipulating certain materials, they can advise where it can be sourced
  • Approach demolition contractors and buy the stone from different buildings, like one of my clients did. The stone was then mixed up in the field next to them and the result is a lovely weathered natural random stone for their new farmhouse
  • Specialist society groups, such as the Society for the Protection of Ancient Buildings (SPAB), Historic England and local architectural societies, can offer guidance
  • Accredited conservation architects have undergone additional training and some will have specific skills, experience and knowledge of stone and stone repair

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