Quarrying

Natural stone has been quarried for centuries in many countries around the world. By the late 1800’s in Australia, sandstone was commonly quarried and used in large structures such as bridges and public buildings due to its strength, durability, availability and beauty. This trend continued until the start of World War II, when production declined. The onset of war caused a depression and many quarries stopped operating. Around 40 years later in the late 1980’s stone not only experienced resurgence as a popular, structural building material, but a practical and attractive choice for interiors and furniture.

Over the past 20 years, the popularity of natural stone has continued to grow in Australia, encouraging the resurgence of the quarrying industry. The trend continues today with architects combining the beauty of natural stone with imaginative designs to create magnificent effects both inside and outside.

Australia has significant deposits of natural stone and many operating quarries. The texture, colour and character of each type of stone vary from quarry to quarry depending on the minerals in that area and the physical environment. These differences allow for more variety when designing interiors and choosing stone. Some of the operating quarries in Australia are listed below:

• In Western Australia marble is quarried in Maroonah, granite in the Fraser Ranges, Esperance, Jerramungup, Bruce Rock and Watheroo, limestone in Moore River, Seabird and Postans, sandstone in Donnybrook, Karratha and Mount Jowlaenga, and other stones in the Ord Ranges and Mount Barker.
• In Queensland sandstone is quarried in Helidon, Murphy’s Creek, Warwick and Beaudesert.
• In South Australia granite is quarried in Wallaroo, Streaky Bay and Black Hill, slate in Mintaro and limestone in Waikeri and Ramco.
  In Victoria granite is quarried in Benambra and sandstone in the Grampians.
  In New South Wales granite is quarried in Tocwal, Dundee and Gosford.
  In the Northern Territory granite is quarried in Tennant Creek.

Quarrying methods vary depending on the type of stone being quarried and the equipment available. Quarry operators look for natural joints in the stone, so they can split it and cut it to size. Explosives are often used with great expertise, so blocks can be obtained in required sizes.

In the case of granite, large blocks are removed from the ground using explosives. When quarrying marble, operators must be very careful not to shatter the stone so they use machines that channel through the stone rather than explosives. Sandstone is removed using an excavator or crowbar, or is split using metal rods and plugs. The metal strips are placed in the holes and the plugs are hammered between the strips, which splits the rock.

Once the stone has been removed from the quarry it is transported using heavy duty trucks and machinery to a processing area where it is cut into slabs. The size and thickness that the slab will be cut to will depend on its final use.

After cutting, the slabs are ready for use unless further enhancement is required, such as planing, profiling, texturing, polishing or honing. In this case specialised saws, some incorporating computer technology, are used to create a variety of shapes, designs and surface finishes. Some pieces requiring more detail are crafted by a stonemason.

From the quarry processing site, the stone is then carefully transported to the manufacturer. Natural stone is extremely heavy therefore specialised machinery and vehicles are required for lifting and transport.

Manufacture / Installation

Benchtops

The manufacturer of benchtops, vanities and other surfaces, purchases whole slabs of finished stone from the quarry. Slabs are displayed so the end user or installer can view the stone and evaluate according to their needs. Once the customer chooses a stone and edge profile, the manufacturer measures the installation area and prepares the slab according to the specifications of the customer. It is advisable when installing a sink or hotplate that the item be on site so the manufacturer can take exact measurements. The manufacturer considers the following when measuring a benchtop or vanity for installation:

• The suitability of the stone chosen
• The thickness of the stone (20mm minimum for benchtops and vanities)
• Where the joints will be located
• Where the sink or hotplate will be located
• Which side the sink drainer will be on
• Where the plumbing and wiring will be located
• Whether the surrounding cupboards are level so the stone sits level
• Whether the surrounding cupboards will provide adequate support for the stone
• Whether the windows above are level so the line of the stone and windows are parallel
• Whether the sink depth will fit in with the structure of the cupboards below
• If there is a vein or grain, the direction and whether it will line up with other pieces of stone
• If there will be enough slabs in the batch to complete the project

Once the preparation is complete the stone slab is cut to size using machinery such as a bridge saw, and edges detailed and polished.

Tiles

Stone tiles are produced by a tile manufacturer. Slabs are cut into standard tile sizes and thicknesses (usually minimum of 10mm for floors), polished or honed and sold to a distributor who sells the tiles to the end user. It is not common practice for the end user to purchase tiles directly from the manufacturer or wholesaler.

Floors

Prior to installation of floor tiles the installer will check the ground to ensure the surface is level. If it is not, a sand and cement screed will be applied, which may incur an additional cost. The floor must be level so the tiles can be laid evenly. As natural stone tiles can vary in colour, texture and pattern from box to box, the tiler should use a selection of tiles from each box, rather than use a box a time to ensure that any slight variation is blended throughout.

Prior to installation of shower tiles the end user must also choose the grout colour with the installer and check the quality of the tiles when they arrive on site as they can vary. Open several boxes and check a random tile from each. Look for:

• Consistency of colour, thickness and size
• Quality of the finish – scratches, dull patches, holes, cracks, chips
• Consistency of the arris (edge)

Showers

When installing tiles in a shower there are several considerations:

• The floor has a good fall towards the drain so water does not pool around the sides and seep into and behind the tiles. This is especially important where the glass meets the floor and there is no hob (step)
• Adequate waterproofing - best results are achieved if 2 membranes are applied – one below the tile to prevent leakage and one below the sand cement bedding as a back up
• Plumbing and fittings are installed before tiles are laid
• Floor tiles are laid before wall tiles so that the wall tiles sit on top of the floor tiles – this prevents water from flowing down the wall and under the floor tile
• Edges and corners are polished and not sharp on shower steps or shelves

Once the stone benchtop or vanity has been prepared to specifications by the manufacturer, the installer will fix the stone in position with special glues and resins. The end user must choose the colour of the epoxy resin used to fill the joints with the installer, so it matches perfectly with the stone. The wrong colour can change the look of the stone.

After installation it is also advisable to have all stone professionally sealed with a penetrating sealer to help protect it from staining and moisture.

Customer considerations when choosing stone slabs from the manufacturer or tiles from the tile distributor are covered in the ‘Tips for choosing your stone’ section.