The range of materials used for interior decoration in the home has increased enormously as people have broken away from the traditional wallpaper or paint as a wall covering. One trend is to reconstruct the ‘natural’ effect, particularly through the use of stone.
This is always popular, particularly as material for fireplace surrounds. The costs, however, have risen steadily over the years; this is due mainly to the fact that as the quarries have been worked out, natural stone has become less available.
By far the most popular material for interior stonework is reconstructed stone, which is manufactured in the form of blocks or thinner sections like tiles. The demand for this type of material has increased in recent years, particularly where planners are conscious of maintaining the traditional appearance of existing architecture and matching the environment when renovating properties.
This type of stonework has some significant properties. It will last indefinitely and therefore needs no decorating; if anything, it will probably improve with age. It is also sufficiently versatile for individual designs to be created — an advantage for those who want to break away from the standard kit designs. Its application is relatively straightforward, particularly since it does not involve the skills required of a stonemason.
The various shades of stone available from different manufacturers are achieved by adding pigments to the mix. These are formed to coincide with the natural stone colours and their place of origin; for example, blue-grey is typical of West Wales, ginger brown of the Midlands, light rust brown of the West Country and creamy grey of the Cotswolds.
Where a range of colours is required to accommodate a design which incorporates varying shades, one manufacturer supplies reconstructed stone in yellow, green, light grey, dark grey, brown and red; these colours give the appearance of stones from different areas; light grey, for instance, is the natural colour of Wenlock stone.
One type of reconstructed stone, which is used specifically for wall facings, is produced in four colours — buff, grey, green and fawn. Another range of interlocking stone tiles offers a choice of six colours.
Types of stonework
Several manufacturers produce reconstructed stones; some make stone blocks which can be used in building work, while others make thin blocks intended solely as facing material to cover an existing or newly built structure.
Apart from their use as building or facing blocks, stones are available in kits to make up individual features. These include the traditional fireplace, which comprises a kit of stones numbered on the back; the numbers correspond to a working plan, making assembly a simple matter.
One make of wall tile can be used both inside and outside the house. Interior work areas such as walls, alcoves, partitions, chimney-breasts and cocktail bar fronts can all be decorated using this material.
Two types of this tile are available — coursed and random.
Coursed tiles are each the height of a single course, but are laid in such a way as to give irregular vertical joints; this helps maintain the natural effect. Random tiles are available in six different sizes; they are designed to interlock with each other and the variety of size ensures a traditional, more rugged appearance. Both types of tile come in two colours. Cotswold is honey-coloured, resembling new limestone; weathered ham has a brown shading which varies from tile to tile to help create a weathered appearance.
One make of reconstructed stone used specifically as a wall facing is made in four sizes. The 15mm thick pieces are supplied in single or multicoloured packs to cover an area of about 1sq m; adhesive and grout are included.
A new range of interior stone cladding is made in six sizes for application to any sound, properly prepared surface using special adhesive. The tiles, which have to be conditioned for at least 24 hours to the temperature of the room in which they are to be fixed, are supplied in boxes to cover nearly lsq m (or 1 sq yd); they interlock to form a random pattern. External corner bull-nosed tiles are available in this range — including different colours.
When planning a design in stone, decide what special features you want — such as recesses, seats and lights. Check with the information given by each manufacturer as to the size of stones or tiles available to calculate accurately the overall dimensions of your particular design. Remember where applicable to make an allowance for joints between individual stones or tiles — usually about l0mm. If you can calculate this accurately, you will reduce the need to cut any of the stonework.
Take care when choosing colours. It may be tempting to include every colour available to create a multi-coloured feature, but often two or three colours will show off the stones to their best effect — and single colour designs are always successful.
A number of designs for room features is available; one manufacturer produces component kits utilizing separate honey-coloured blocks 100mm (4in) thick. Each block is numbered to coincide with that particular building plan and Welsh slate slabs are used as capping pieces.
These designs are specifically intended for rooms without an essential focal point, such as a fireplace or chimney-breast. They will provide a substitute focal area, although there is no reason why they should not be used in a room which already contains an acceptable focal point. The designs range according to your storage needs, such as a TV, hi-fi, books, aquarium or jardiniere. As with the usual fireplace kit, building instructions are supplied together with mortar for building and pointing. A detailed diagram indicates the location of each component.
In some cases you can order your own kit of components to make up a fireplace design of your choice; you will have to submit a rough sketch of the appearance and dimensions you require.
These designs are specifically for use against a wall; they are in no way suitable for use as components of a free-standing unit. The type of stone used in these kits is split mechanically to give a rough hewn effect resembling dressed natural stone. Dressing is the term used for the shaping treatment given to natural quarried stones. The stones are available in five sizes.
Preparing the surface
Before putting up any stonework, certain precautions must be taken. You should protect the floor and any furniture you are unable to remove from the room with dust sheets or newspaper; the work is bound to produce stone chippings and dust.
Stone tiles require the same surface for laying as ceramic tiles. Make sure you have a solid, even surface which is clean and free of stripped wallpaper or flaking paint.
Before you start to fix the stones or tiles in position, lay them out on the floor to establish the final pattern and number each one in order so you fix them up in the same pattern. When deciding on a pattern, avoid any cross joints — where four tiles meet at their corners.
Depending on the stonework you are fitting, there are several methods of application. Generally the recommended adhesive is spread or dabbed onto the back of each tile; or you can spread the adhesive onto a section of the surface to be covered. The latter application of adhesive is recommended where you are laying tiles onto a slightly uneven surface. It is best to work on small areas at a time — usually up to lsq m (or lsq yd). Take care not to get any adhesive onto the edges or fact of the stones or tiles; if you do, wipe it off immediately with a clean dampened cloth.
Work from the bottom upwards, laying your stones or tiles one course at a time. Make sure you are working to a true vertical and horizontal, otherwise the overall effect of your stonework will be spoiled. These can be checked with a spirit level, timber straight-edge and a plumb line.
To ensure the best overall effect, it is important to maintain regularly spaced joints, both vertically and horizontally, between the stones or tiles. This can be done by using spacers — or wood offcuts — about 10mm thick; insert them at regular intervals between adjoining stones or tiles as they are positioned. One manufacturer produces ring spacers to fit between the stones. These are removed as the finish is applied to the work (see below). Some lightweight stonework will retain its position on the adhesive and will not require the use of spacers.
Provided you have made accurate calculations and decided on your design accordingly, it should not be necessary to have to cut individual stones or tiles. Depending on the type and its thickness, you can use an old saw, hacksaw or power drill attachment. With the larger type of stones you will have to use a cold chisel and club hammer. One manufacturer recommends cuts are made across the width of the stone and never along its length. Having marked the cutting line in pencil on the back of the stone, you should stand it on edge on a firm surface and tap down smartly with the chisel held vertically. One blow should be sufficient to remove the corner piece; turn the stone the other way up and repeat the operation at the other end. To complete the cut you should lay the stone on its face and chisel away the remaining stone. The rough edge produced will blend in with the rest of the stones.
This depends on the type of stonework you are using. In some cases pointing is not necessary; any surplus adhesive pushed up through the joints can be flattened down after about an hour with the square edge of an old screwdriver. If you wish to point the joints, most manufacturers recommend a period of 24 hours to allow the stonework to set in place. A stiff mortar mix can then be applied with a pointing trowel or similarly shaped piece of wood; the mix should be slightly damp, although you should be able to hold it without it sticking to your hand. Remove any spacers you have placed between the stones or tiles as you work.
For a slightly recessed finish to the joints, run a cloth-covered thumb or finger along them before they have set. As a general rule, complete the vertical joints in each course first. Excess mortar should be removed with a dry brush before it sets hard; avoid smearing the face of the tile with mortar.