How To Choose The Finish For Your Natural Stone Pavers

Natural stone pavers are a great choice for any size, shape and style of garden design. But the array of stone finishes available can be incredibly confusing - particularly for clients who are unfamiliar with the landscape industry.

Here’s our guide to natural stone finishes.

What Are The Differences Between Sawn And Riven Pavers?

As you can imagine, natural stone pavers start life as enormous blocks of stone extracted from quarries. These blocks then need to be shaped into regular sized pieces for easy transport and installation.

There are two main techniques used to shape paving slabs and natural stone setts. Sawn and Riven.

Sawn: Just as the name suggests, massive power saws, usually controlled by computer, are used to cut all 6 surfaces of the slab with amazing accuracy. Sawn slabs are a dream to work with, particularly if you are looking for precision, neatness and regularity.

It’s not unusual to refine the finish on sawn slabs with techniques such as acid washing, honing, bush hammering, flaming or tumbling. More on those later in this article.

Pro’s - Accurate shapes allow for precision installation

           Leaves a slightly textured surface with great anti-slip properties

Cons - Occasionally Saw marks can impact the aesthetic (however these can be negated by additional finishes)

Riven: The stone is split along its layers creating a very natural finish to the slabs. Surfaces have a very organic texture with slight ridges. No two riven slabs are exactly the same. So think character, rustic charm, ageless and unique. That makes them-perfect for a rustic or cottage garden aesthetic but perhaps not ideal for poolside applications. Riven slabs are particularly popular where slip resistance is an important factor.

Using specialist machinery to shape limestone pavers

Surface Finishes

When you browse the natural stone products on the Arbour Landscape Solutions website and you’ll find a whole host of terms describing the surface finishes. Each one of those surface finishes gives a very slightly different aesthetic meaning that garden designers have plenty of options to make their creations unique.

Tumbled Edges

Slabs are given a softer, more worn appearance by gently tumbling the pavers in a rotating drum along with pebbles, sand and water. Just like rocks on a beach, the action knocks back any sharp or rough edges to the stone giving it a timeworn appearance.

Tumbled paddlestones are particularly popular among Arbour Landscape Solutions clients. These are great for facing retaining walls, planters and step risers. They lend a heritage look and feel to any design project.

Riven stone surface showing the natural shapes and textures revealed when layers of rock are split

Tumbled edges have a softer, more organic look and feel than untreated sawn edges. This Galala Limestone has an acid etched surface which highlights the natural colour variations within the stone.

Acid Washed/Acid Etched Finish

Slabs are momentarily treated with a solution of acid which is almost immediately rinsed off. Why? All natural stone is composed of a mixture of minerals. These minerals determine the colour, durability and density of the stone. Each of those minerals will behave differently when introduced to acid or alkaline substances. In the case of acid washing, a proportion of the mineral salts within the natural rock will react with the acid, while the remaining elements and compounds remain unaffected.

Exposing natural stone to acid for a very short period of time results in some of the minerals being dissolved, thus leaving a wonderfully textured surface. Of course, this needs to be done under carefully controlled conditions in order to protect operatives and the environment. Timing is everything. It's crucial that the acid/mineral mix needs to be washed off before it can penetrates deep into the heart of the rock.

All in all, acid washing results in a visually attractive and slip resistant surface which is popular with garden designers and clients alike. However, not all stone types are suitable for acid washing and acidic stone cleaners should be used with extreme care on any stonework.

A bush hammer and other stone mason's tools. Paving finishes are normally achieved using mechanical bush hammers which give a regular pattern.

Bush Hammered Surfaces

Bush hammering sounds violent - and it is! But it does make a fascinating surface feature. A bush hammer is a traditional masonry tool used to texturise concrete and stone. It’s name is derived from the German word bossen which means ‘to beat’.

The stone surface is repeatedly pounded with a bush hammer to create a wonderfully textured face. This finish beautifully accentuates the colours within a natural stone and of course creates a reliably slip resistant, matt surface.

Honed Pavers

Honing is a process very similar to the sanding we use to create a smooth surface on the timber elements of a garden. It’s basically a type of gentle polishing which, whilst it doesn’t create a shiny sheen, it does have a silky smooth look and feel.

Honed natural stone is great wherever you want to create a contemporary or minimalist look and feel, however it is less slip resistant than sawn or riven surfaces. A reminder of the importance of understanding exactly how the householder plans to use their outdoor space in the foreseeable future.

Only the other day, the well respected garden designer David Lloyd reminded Richard that some clients prefer a smooth surface, not just for the aesthetic, but because it’s less likely to trap dust and detritus than riven or textured surfaces.

Flamed Finish

At Arbour Landscape Solutions we love a flamed finish. It’s especially effective on granite and is created when the rock is subjected to a heat so intense that some of the mineral crystals literally burst.

The resulting finish creates spellbinding markings on the surface of the stone and adds a subtly undulating texture that feels wonderful on bare feet.

Honed Egyptian Limestone patio designed by Heartwood Garden Design. The smooth surface is a perfect contrast for the aggregate pathway and also complements the texture of the fabric furnishings

Dark Grey Meli Limestone with an acid etched surface. These contrasting colours are particularly striking. With lighter coloured stone the effect is more subtle

Dark Grey Meli Limestone with a flamed finish. The overall effect is of aged stone. Ideal for a garden design where there is a desire to create a sense of age and maturity

Right Stone, Right Place

As a garden designer, your first priorities when considering stone finishes are likely to be the aesthetic and the slip resistance. But please remember that, just like plants, it is important to specify the right stone for the right place.

For example, a particularly porous stone installed in a shady spot is highly likely to attract algal growth. Slippery green pavers can only lead to disappointment which could so easily be avoided by taking extra care at the specification stage of a project.

If in doubt, the team here at Arbour Landscape Solutions will be able to help you with information on how different stone types are likely to behave in different circumstances.

A Word About Sealants

Natural stone has a propensity to be porous - which works brilliantly in the grand scheme of our planet’s hydrological cycle. However in a domestic situation, that absorbency does mean that it is at risk of being permanently stained by ordinary lifestyle events such as spilt wine.

Not all stains come from spillages either. In certain circumstances, salts encased in the structure of natural stone will work their way to the surface of the stone appearing as either rusty-looking marks or as a white bloom known as efflorescence.

The team here at Arbour Landscape Solutions strongly recommend that any natural stone pavers are carefully sealed to protect them from accidental spillages and from possible water ingress which may cause unsightly marks.

When you specify natural stone products from Arbour Landscape Solutions, please let us know if you would prefer it to be pre-sealed (easier for everyone on site) or if you wish to purchase the sealant separately. If you’re not sure, don’t worry, we’re happy to answer any questions you may have.