|
|
 |
 |
 |
 |
|
PATIO PAVING
NATURAL STONE
Crazy Paving |
Introduction and types
There's no paving finer than natural
stone; it's been used for thousands of years and represents one of
man's earliest technologies - the ability to make a traversable
pathway. It will outlast all of us, every unit is unique, it's a
natural product with texture and colour determined by millennia of
geological processes rather than modern chemical dyes, it's incredibly
strong, hard-wearing and if all that wasn't enough, it's also
beautiful. |
Slate paved patio
|
Granite Flagstones
|
Yorkstone Paving
|
|
The stone paving most commonly used in mainland Britain is the
legendary 'York' stone, hewn from the Pennine grits of northern
England, and used to pave the streets of the capital, along with almost
every other major town in the country up until the last century. But
there are other stone products used for paving - Pennant from
Gloucestershire, slate
from Wales and Cornwall, Liscannor from Co. Clare, limestones from
Derbyshire and North Yorkshire, granites from Shap and Aberdeen,
basalts, whinstone and a host of other rock types, from each and every
region of these islands. |
|
Increasingly though, we are seeing more and more stone imported from
more exotic parts of the world. There has been a surge in the supply of
an Indian Sandstone that is similar in appearance to our own Yorkstone but sells for slightly less per square metre.
There are also granites from Brazil and China, marbles and slates from
southern Europe, all supplied as what we would term 'flagstones', as
well as cubes, setts and cobbles in hardstones such as gabbro and diorite.
|
Indian Sandstone Flags
|
Yorkstone circle cut to exact shape
|
Amazingly powerful, modern machines with the latest diamond blade
technology allow stone to be cut and dressed with a fraction of the
effort required by the quarrymen and streetmasons of old, and there is
now stone paving available to whatever plan size, thickness and finish
is required. Stone can be custom cut to create fan radius details, cut
to sizes to use with other manufactured paving units and given a wide
range of special finishes. |
|
All this comes at a cost, though. Stone paving is not particularly
cheap when compared to the concrete alternatives, and even reclaimed
stone paving has a healthy re-sale value. In fact, it is not unheard of
for whole streets of stone paving to be 'stolen' by thieves
masquerading as council operatives, and for private driveways and
patios to be lifted and removed overnight. |
New or reclaimed?
Reclaimed stone flags, i.e. salvaged from old streets, yards or
wherever, usually have more immediate character than newly cut
flagstones, and are considerably cheaper. The newly cut flagstones will
develop their own character over time, as they are weathered and worn,
but they can look amazingly pristine when just laid. The reclaimed
flagstones add instant charm to period properties, and look great in a
garden setting, but they can look mis-matched when used for a driveway
on newer, modern properties.
Both new and reclaimed stone flags are suitable for most
applications. Any 'flag' thinner than 20-25mm is more a tile than a
flag and should only be used in the least strenuous of applications,
and then preferably on a full mortar bed, much as a tile is laid. The
25-60mm thick units are best suited for non-vehicular usage, such as
paths and patios, the 50-75mm thick for heavier applications such as
streetworks, while the 70-150mm thick units are typically reserved for
paving that is likely to experience some low-speed vehicular traffic,
such as commercial or civic projects and for residential driveways. |
Buying New
With new paving, the supplier will normally offer a choice of
thicknesses, and they will then be cut to suit the specification. There
is also usually a choice between paving that is 'sawn 6 sides', 'sawn
top and bottom', and 'natural cleft', but this depends on the type of
stone from which the flags are cut and the individual supplier. Some
quarries supply flagstones that are sawn on the top surface only, with
a cleft base and fettled edges. |
|
|
New stone paving is now available in a wide range of finishes, such as
'combed', 'riven', 'picked' and 'flame-textured'. Some manufacturers
offer finished that are only available with their products, either
because of a unique characteristic of the stone itself or resulting
from a special finishing process. While some finishes will retain their
special character for many years, others will disappear after a couple
of seasons of heavy pedestrian traffic.
Special consideration should be given to choice of finish, with
attention given to planned use of the paving as well as aesthetic
and/or design considerations. Honed, sawn or other smooth finishes may
be better suited for projects with heavy pedestrian usage or where
shoppers use trolleys. Heavily textured finishes, such as chiselled or
punched, are better suited for projects where additional traction is
important, or where a definite 'look' is required. |
|
New paving is nearly always sold by area, rather than by weight, which
makes ordering very simple. It tends to be supplied in standard course
widths based on 150mm modules, so we see lots of new paving that is
300mm, 450mm or 600mm in width and of variable length. Most
manufacturers are happy to supply specific lengths or to cut
non-standard widths, if they are required. |
Diamond Sawn Yorkstone Paving
|
Sawn Slate Paving
|
| Although
stone paving is considerably more expensive than the concrete
alternatives, or the increasingly popular block paving, it does have a
cachet that no other form of paving can offer. It has an indefinite
life-span and a high re-sale value should it ever need to be replaced.
Prices are variable, depending on type of stone, source, finish,
thickness etc., but expect to pay £30-£70 plus VAT per square metre for
a typical 30-50mm thick flagstone. |
| One advantage of
buying new is that manufacturers are generally delighted to work with
the designer to apply their not inconsiderable skills and technologies
to supply unique and, in some cases, absolutely stunning paving.
Special shapes can be cut to order, and special finishes applied to the
new paving. Many of the paving manufacturers are also able to supply
matching or complementary hard-landscaping items, such as steps,
plinths, copings, seating, etc. |
|
Buying reclaimed
|
|
There is a thriving market in reclaimed paving, and as with any
business, there are honest dealers and there are rogues. The rogues
tend not to stay in business for very long and often do not have a yard
or other business premises. Be very wary of any dealer who has only a
mobile telephone number or who insists on doing business in cash from
the back of a lorry.
Remember, the thicker the flag, the less you get per tonne! Always
try to buy by area, not by weight. If you buy reclaimed flags by
weight, the less scrupulous dealers will probably slip in a couple of
monster 175mm thick ones (known in the trade as 'ball-breakers'!) that
no-one else would take. |
Reclaimed paving in a garden setting
|
There is a great deal of variation in the quality of reclaimed paving.
While some is as good as the day it was originally laid, albeit with a
bit more character, a significant proportion of what is offered for
sale is of dubious quality. In particular, look out for...
- Flaky paving - some flagstones cleave along the bedding planes over time
- Missing corners - can be tidied up by re-dressing the flag but extra work involved.
- Paint/Oil/Mortar stains - can be difficult to remove; see Stains page
- Roofing Tiles sold as paving flags - generally these are less than 25mm thick
- Non-rectilinear units - some flagstones may be tapered or trapezoidal in shape
- Lanolin - flags from old woollen mills contain high levels of nastikemmickles
|
Coursed Paving
|
Another consideration when buying reclaimed stone paving is the course
width. Most stone paving was, and still is, produced to standard widths
to enable simple coursing of the flags. Quite often, we find that
reclaimed paving has a course width that is a multiple of a 3" module,
so we see lots of paving that is 18", 21", 24", 27", 30", 30" or 36" in
width, with variable lengths. This feature can be very useful when
buying paving for a large area that will be laid to a course pattern,
as most good dealers will sort their stocks according to course width,
if asked to do so. |
|
One of the most significant difficulties when working with the
reclaimed flagstones is the variation in thickness. Although dealers
often sort their flagstones into, say, 30mm thick, 50mm thick, etc.,
there is a generous degree of tolerance in these figures, so that what
is classed as 50mm thick can be anything between 40mm and 60mm.
Obviously, this precludes the use of a screeded bed for laying the flagstones, and it can be trial and error to achieve the right individual bed for each flag.
Reclaimed ("second-hand") stone pavings command a price of £15 - £90
per square metre, or more. The better the quality, the higher the
price. This compares favourably with the cost of new stone flags and
gives the better quality wet-cast concrete reproduction patio flags a run for their money. However, quality is everything and all reclaimed paving should be thoroughly vetted before purchase.
|
|
Although Pavingexpert does not supply or sell ANY materials, not even
reclaimed flags, the website has a partnering arrangement with
Yorkstone.co.uk to source and supply the very best quality reclaimed
flagstones and kerbs to those clients looking for guaranteed materials.
Visit the Yorkstone.co.uk website for further details.
|
Crazy Paving
|
| The
term "crazy paving" refers to the 'crazed' appearance of the finished
surface, although it could equally apply to the notion held by some
folk that it is a cheap or easy form of paving. Far too often, it is
undertaken as an allegedly simple alternative to more traditional
paving, or because the stone itself is cheaper than rectangular units,
yet, from a contractor's point of view, it costs more in terms of
labour to lay a given area of crazy paving than it does for 'normal'
paving.
Many types of stone paving can be obtained in non-rectangular
shapes, which is a trade term for broken bits and pieces. We refer to
this type of stone paving as "random rubble" and it can be laid as
crazy paving to good effect. However, as hinted at above, there is a
lot of intensive work involved in getting crazy paving to look good.
The rubble has to be sorted, and the best or most appropriate pieces
selected and laid, one at a time. Each individual piece needs to be
kept as tight to its neighbours as is possible. Good crazy paving
minimises the amount of mortar or jointing visible at the finished
surface. Often, to achieve this, the rubble has to be trimmed or shaped
with hand tools to get a reasonable fit and avoid those unsightly 100mm
wide dollops of glaring mortar. |
Slate crazy paving
|
Poorly pointed yorkstone
|
|
However, it is a traditional form of paving in some parts of the
country, notably those areas where workable stone is at a premium, and
when done carefully, it can be visually stunning. It does, however,
need to be laid on a full bed of mortar or concrete, rather than clean
sand, and the mortar pointing is absolutely critical.
In terms of cost, random rubble suitable for crazy paving can be
found for as little as £5 per square metre, although prices in the
range £12 to £25 per square metre (all plus VAT when applicable) are
more common.
See the Crazy Paving page for more detail on this type of paving.
|
Construction
Most stone paving can be laid onto a grit sand
bed, but thinner units, such as some of the slates, need to be laid on
a full mortar or concrete bed. There are only 2 layers to stone paths
and patios; the flags themselves and the bedding layer. Pavements that
will experience vehicle overrun, such as drives and forecourts, should
add a sub-base suitable for the prevailing conditions, or may use a
concrete sub-base with the flagstones laid directly onto the concrete
before it sets. This method allows the thinner flags to be used for
driveway purposes.
See Laying Flags page for fuller details on how to lay stone flags.
|
|
Although most stone paving is laid with pointed mortar joints,
the units with sawn edges are sometimes laid with 3-6mm wide dry sand
joints. Butt-jointing (flags laid tight against their neighbours) is
not normally recommended, as the tight joints can often cause the stone
to spall on the top surface, although this can be largely avoided by
using chamfered stones on those projects where butt-jointing is
required. |
|
It has already been mentioned that stone flags are available in almost
any plan size you can think of, and it is this variety of sizes that
allows custom patterns and random layouts to be laid with the stone.
Random layouts are extremely useful with reclaimed flags where there is
less chance of stipulating exact widths to allow coursed work to be
laid without having to trim most of the flags.
By choosing flag sizes carefully, it is possible to create simple
but attractive patterns, such as this herringbone layout created with
just one size of flag, 900mm x 300mm. |
|
|
However, certain layouts, such as streetworks and footpaths, look much
more effective when laid in transverse courses (courses that run across
the direction of travel) or longitudinal courses (running in the
direction of travel), and it is generally only larger areas such as
forecourts and patios, that are laid as a random layout.
See Random Layouts page for fuller details of creating random layouts.
|
|
There
is also a tradition of prestigious civic paving projects using natural
stone in highly specialised, often unique patterns that require the
stone to be specifically cut, often to non-rectangular shapes. This
custom perhaps reached its peak during the Victorian and Edwardian
eras, when streetmasonry was an indicator of civic pride and
prosperity, but there is a definite revival taking place as developers
and architects re-discover the vital role played by the built
environment in creating our everyday culture. |
|
It was noted earlier that reclaimed stone flags usually have variable
thicknesses and therefore need to be individually bedded, whereas new
stone can be bought in specified thicknesses. Some flags are
exceptionally heavy and may require two or more flaggers to handle them
safely. The really big stuff, such as those units of 1800mm or more,
are usually manoeuvred into position with the aid of crow bars or slung
from the hydraulic arm of JCB. |
Construction Diagram
|
See Laying Flags page for more information on laying techniques
|
Coverage
Coverage rates are very variable, given the random nature of the stone
paving, and the inconsistency in thickness. New paving is normally sold
by area, except in specific circumstances where large areas of known
dimensions are required. Some dealers still sell reclaimed paving by
weight, which can lead to arguments and even fisticuffs when a
disgruntled buyer finds 20 tonnes of 200mm thick paving dumped on their
job!
Most stone used for paving has a density of between 2,200 and 3,000 kg per cubic metre. So, for guidance only....
- 1 tonne 25mm thick slate flagstones covers approx 15m² - (2,800Kg/m³)
-
- 1 tonne 50mm thick sandstone flags covers approx 8.5m² - (2,400Kg/m³)
- 1 tonne 75mm thick sand stone flags covers approx. 5.5m² - (2,400Kg/m³)
-
- 1 tonne 50mm thick granite flagstones covers approx 9.5m² - (2,600Kg/m³)
- 1 tonne 100mm thick granite flagstones covers approx 4.5m² - (2,600Kg/m³)
|
Pros and Cons
- Quite expensive, when compared to concrete pavings.
- Well-laid stone paving is both time consuming and labour intensive.
- With reclaimed flags, just arranging them into a reasonable pattern can be like solving a jigsaw.
- Good quality stone flags, well laid and in the right setting, truly are a joy to the eye - very natural and organic looking.
-
If employing a paving company to do this sort of work, insist on seeing
previous work in the same materials, as the skills required to lay
stone paving are not the same as those used for block paving.
- No risk of colour fade as there is with coloured concrete products
- Must be properly drained to gullies or other suitable drainage points.
|
|
For easier and cheaper alternative to yorkstone flags, take a look at
some of the very good concrete copies that have become available
recently or see the decorative paving section of this site.
Until a few years ago, all of the concrete copies were appallingly
unconvincing, but the newer products, such as "Old Lancashire" by Westminster Stone and "Millstone" by Stonemarket, are exceptional - have a look at the photograph opposite - real or copies?
|
|
Maintenance
Natural stone paving is very low maintenance once laid. The pointing is
the weakest element and may need to be replaced after a number of
years.
Sweep regularly with a stiff brush to remove dust and detritus.
There is a tendency for algae, lichens and mosses to colonise stone
paving that is permanently shaded and/or damp. This can be safely
removed by a pressure washer or, we are told, by swilling the area with
Jeyes Fluid to kill the algae, which can then be swept away after a
couple of days.
They should last longer than any of us!
|
|
| |
|
 |
 |
 |
 |
|