- Understanding Stone
- Installation Of Stone Pavings
- Sandstone Sealing, Care & Maintenance
- Limestone Sealing Care & Maintainence
- Spirit Product Profile
- Protectastone Product Profile
Rocks are made up mostly of crystals of different kinds of minerals, or broken pieces of crystals, or broken pieces of rocks. Some rocks are made of the shells of once-living animals, or of compressed pieces of plants.
Granite is a common and widely-occurring type of intrusive felsic igneous rock. Granites are usually a white or buff colour and are medium to coarse grained, occasionally with some individual crystals larger than the groundmass forming a rock known as porphyry. Granites can be pink to dark grey or even black, depending on their chemistry and mineralogy.
Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3). Limestone often contain variable amounts of silica in the form flint, as well as varying amounts of clay, silt and sand as disseminations, nodules, or layers within the rock. The primary source of the calcite in limestone is most commonly marine organisms. These organisms secrete shells that settle out of the water column and are deposited on ocean floors as pelagic ooze. Secondary calcite may also be deposited by supersaturated meteoric waters (groundwater that precipitates the material in caves). This produces stalagmites and stalactites. Pure limestones are white or almost white. Because of impurities, such as clay, sand, organic remains, iron oxide and other materials, many limestones exhibit different colors, especially on weathered surfaces. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock.
Travertine, a natural stone, is a white concretionary form of calcium carbonate that is usually hard and semi crystalline. It is deposited from the water of mineral springs (especially hot springs) or streams holding lime in solution. When carbon dioxide-rich water percolates through earth and rocks in limestone areas, the water dissolves the limestone and becomes saturated with it. When the water resurfaces later, the sudden drop in pressure and the change in temperature cause the water to release the carbon dioxide gas, much like fizzy drinks. The limestone then recrystallizes, often over minute underwater plants. With time, the mineral deposits harden and become stone.
Marble is a metamorphic rock resulting from the metamorphism of limestone, composed mostly of calcite (a crystalline form of calcium carbonate, CaCO3). It is extensively used for sculpture, as a building material, and in many other applications. The word 'marble' is colloquially used to refer to many other stones that are capable of taking a high polish.
Sandstone is a sedimentary rock composed mainly of sand-size mineral or rock grains. Most sandstone is comprised of quartz and/or feldspar because these are the most common minerals in earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow, red, gray, and white. Some sandstones are resistant to weathering yet are easy to work. This makes sandstone a common building and paving material. Because of the hardness of the individual grains, uniformity of grain size, and somewhat friable nature, sandstone is an excellent material from which to make grindstones for sharpening blades and other implements.
Slate is a fine-grained, homogeneous, metamorphic rock which was derived from an original sedimentary rock composed of clay or volcanic ash through low grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering.
Installation Of Stone Pavings
1 - General Preparation
Remove all weeds and other unwanted organic matter. Excavate any soft spots and fill with compacted sub-base material. If the area of the paving is troubled with weeds, you may treat the excavated sub-grade with a general weed killer, but it is unlikely any normal weed will be able to penetrate the upper layers.
Decide where you want the paving to run, and mark out with guide-lines, if required. It is assumed that the paving is to be flush i.e. level, with the pool level. It is a good idea to dig wider than the planned paving width, allowing an extra 75-100mm at the edges makes handling much easier.
2 - Preparation Of The Sub - Grade
The sub-grade layer of a pavement is, essentially, the underlying ground. It is also known as the "Formation Level". Usually, a sub-grade will need some basic preparation to make it fit for construction purposes, and this process is known as 'sub-grade formation' or 'reduction to level'.
The simplest form of sub-grade formation is a 'site-strip'. This process involves the removal of all surface vegetation along with the root zone, approximately 50mm in depth. It is bad practice to construct a pavement over surface vegetation; as organic material, it will decompose, which could lead to the formation of voids in the covering layers, which could, in turn, lead to pavement settlement.
It is only the most straightforward of jobs that will require solely a site strip. Most projects will involve a 'reduction in level', i.e., some degree of digging down to a 'formation level'. There are 2 common reasons for a reduction in level:
- to accommodate the finished levels of paving work
- to remove bad ground, top-soil, soft spots or other deleterious material
For most paving works, the required construction thickness is known in advance. Once finished paving level is established, the thickness of the paving can be subtracted and this will establish 'formation level', i.e., the uppermost surface of the Sub-grade.
Bad ground, soft spots, and other construction works may need the sub-grade to be reduced even further to overcome these problems. It is much more cost efficient to remove any potential trouble-spots at this stage than have to take up a section of the final pavement and re-construct the sub-base.
The formation level of the sub-grade is the base of the construction. It will be overlain by the other pavement layers, which may include a capping layer, if the ground is structurally weak, likely to be subjected to exceptional loads or is significantly below an ideal formation level specified by the project engineer. Capping layers are simply layers of a selected fill material, often a crushed rock, laid in layers not exceeding 225mm (normally) and thoroughly compacted before placing further layers, up to sub-base layer.
3 - Base Layer
This is essential beneath all rigid pavements and must be constructed from a bound material. A bound material is one that becomes monolithic, i.e., all one unit, when set. In 99% of cases this means bitmac or concrete. An existing bitmac, asphalt or concrete surface can be used provided that it is in good condition, not cracked, not subject to settlement or movement and will not compromise any damp-proof courses once the paving is laid. Any base being used in this way should be cleaned, preferably with a power washer to remove all vegetation and organic matter before placing the bedding layer.
Under no circumstances is a un-bound sub-base acceptable in place of this base; a sub-base of loose or granular material, such as compacted earth, crushed stone etc, continues to move over time, and would cause cracking of the rigid paving and bedding layers. There may be a flexible sub-base beneath the base layer in high traffic projects.
A 75-150mm thick base layer is the usual specification. If a bitmac or asphalt base is to be used, this will need to be laid over a prepared sub-base, typically 150mm thick. Rock 'n Stone specify that all their paving to be laid on a concrete base layer , this should be laid on a damp proof membrane (dpm) over a 150mm thick compacted sub-base, or may be laid, again on a dpm, over the prepared sub-grade. A concrete of minimum strength 20mpa should be used, reinforcing steel is recommended.
4 - Movements Joints (or Control Joints )
To control any movement of the solid base layer, it is essential that movement joints are constructed within the base layer and surface layers at intervals of not more than 6 metres. These movement joints should extend through the base layer to the surface of the paving layer as shown in the construction diagram opposite. Movement joints should also be constructed to isolate any fixtures, such as pit covers, lighting columns etc.
5 - Bedding Layer
The bedding material should be a Class 1 mortar, stiff, but retaining its plasticity. The usual mix for the bedding mortar is 1:¼:4 - cement: lime: sand. On some projects the lime is replaced by a proprietary plasticising agent. Do not use yellow brick sand. Add Bondcrete to the mix.
The base layer should be doused with water before placing mortar to prevents the Base layer from sucking the water out of the mortar, rendering it too stiff to bed the pavers correctly. The mortar is spread over the dampened base layer approximately 20-35mm thick, and is 'rippled' with the blade of a trowel to allow the paver to be bedded into the mortar. If working in courses, it is usual to lay out sufficient mortar to complete one course at a time. With other patterns the mortar may be spread out at approx 1m² at a time to ensure the bed is still 'fresh' when the pavers are positioned.
6 - Paving Layer
Being natural stone, the colour and properties of Rock 'n Stone pavers will vary from piece to piece. We recommend the installer select pavers proportionately from each pallet during the laying process to achieve a mix of pavers throughout the job.
A taut string line should be established as a guide to line and level for each course or section of paving. A camber can be created by working to a template or profile cut from timber. The guide line should be moved along as the laying proceeds.
One end and the bottom of each paver is buttered with the jointing mortar and pressed into the bedding mortar and up against the preceding course or edge. Rock 'n Stone highly recommend the addition of a mix of bondcrete and neat cement be painted onto the back of the pavers for additional adhesion. This will stop drummy or lifting pavers occurring. Pavers that need to be cut to fit in at edges should be placed as the work proceeds, and not left until the rest of the pavers are laid, as the bedding mortar will be 'stale' and difficult to replace.
Stone pavers are not difficult to cut with a conventional diamond-tipped blade.
Sandstone Sealing, Care & Maintainence
Rock 'n Stone recommend using only 'Spirit' Marble and Tile care sealers and cleaners on their pavers. Please refer to the attached list for stockists.
Sandstone is a very durable formation of quartz grains (sand). Quartz grains are bound together by other minerals such as silica, calcium, clay and iron oxides. These minerals combined with quartz and pressure form Sandstone which will vary in colour form white to reds to browns. Many Sandstone's look and behave differently because of grain size and varying bonding agents combined with extreme pressure to form high density Sandstone.
When Sandstone is used in areas where soiling or staining are a problem, sealing the stone is the best way to ensure that the stone can be maintained. Spirit Marble and Tile Care suggest the following procedure to clean and seal Sandstone.
For sealing sandstone around a saltwater pool, apply Protectastone which is a solvent based silane/siloxane to the immediate area surrounding the pool, about a 2 m radius. Ensure the pavers are clean, dry and dust free prior to applying this sealer. Using a suitable sprayer, lambs wool applicator or roller, apply the Protectastone (as per manufacturer's instructions) to achieve a final seal that will protect against moisture and in turn salt from affecting the sandstone. Protectastone requires at least 24 hours to dry and cure. Please refer to the attached details on Protectastone.
For the remaining areas, not immediately surrounding the pool, once the Sandstone is fixed and dry the pre-seal can be applied, Pre-seal requires 24 hrs to dry and cure prior to which any cleaning can commence. Once the seal has cured the cleaning process can begin.
Pre-Seal is a water-based seal that cannot be affected by acid or cleaning chemicals. It stops chemical from soaking into the Sandstone and affecting further seals and allows the stone to be cleaned and dried very quickly.
If grout smear is on the face of the sandstone then Phosphoric Acid Cleaner should be used to clean the surface to remove excess grout, rust, minerals and other construction debris. After cleaning with Phosphoric Acid Cleaner, all areas should be rinsed and left to dry, providing the pre-seal has cured the stone will dry quickly.
Once clean and dry the final sealing can commence to the total area, including the pool surround. Using a suitable sprayer, lambs wool applicator or roller, apply Premium Seal in two coats to achieve a final seal that will protect against oil, food stains and most other staining that can occur. For ongoing cleaning use Spirit HDC or Neutral Cleaner to maintain the stone.
Limestone Sealing Care & Maintainence
Rock 'n Stone recommend using only 'Spirit' Marble and Tile care sealers and cleaners on their pavers. Please refer to the attached list for stockists.
Limestone is a porous to very porous stone and when used in flooring should be sealed to protect the stone from effects of water marking, water staining and staining from foods and drinks. In addition to normal staining, limestone can suffer from the effects of tradesmen such as construction debris, cement, grout and heavy foot traffic. To minimize the damage and promote easy cleaning Spirit Pre-Seal should be applied to the face and edges of the tile prior to the stone being exposed to water. Spirit Pre-Seal will act as a grout release and stabilize the stone to keep contaminants near the surface. It is important to allow the pre-sealed stone at least 24 hours to dry and cure before laying or grouting to ensure the full effect.
Once the stone has been pre-sealed, laid and grouted and approximately three days have passed for grouting to harden, the cleaning process can begin. Because limestone is composed of calcium carbonate and other minerals that react with acidic cleaners, no acid should be used to clean or remove cement or grout. If an acidic cleaner is used, damage may occur to the face of the stone. If Spirit Pre-Seal has been applied correctly and cured, grout smear and soiling can be cleaned using Spirit Neutral Cleaner and a brush. This is a simple way to clean and prepare the surface for the finishing products to be applied. Once the stone is clean and dry Spirit Premium Seal can be applied. The coverage rate may vary depending on the porosity but normally 8 to 10 square metres per litre will complete the job. If the stone is inside, a coating such as Spirit Satin Seal may be applied after washing with Spirit Neutral Cleaner. This will limit the beading effect and allow the Spirit Satin Seal to level and dry. Two coats will give long lasting protection and a low sheen to the stone. For daily cleaning use Spirit Neutral Cleaner mopped on and allowed to dry. For periodic heavy cleans use Spirit HDC to remove heavy buildup of soiling.
Spirit Product Profile
Spirit Premium Seal
A solvent based penetrating seal that provides a natural looking finish with long life benefits. Spirit Premium Seal provides the very best protection from both oil and water-borne contaminants. Permits vapour transmission. Mildew resistant. Non-flammable/non-corrosive. Spirit Premium Seal is an excellent top finish over Spirit Pre-Seal. Also available in a handy easy to use "Spray" form called PREMIUM SEAL SPRAY
Spirit Natural Paving Seal
A solvent based penetrating seal that provides a natural looking finish, with long life benefits. Spirit's Natural Paving Seal is designed for exterior paving. Clay products, cement products, sandstone & other natural stone products will benefit from Natural Paving Seal. Natural Paving Seal provides protection from oils & water borne contaminants.
A water based penetrating seal used for pre-sealing stone and other clay or masonry products. For internal and external use. Fast sealing and curing. High resistance to water-borne contaminants. Permits vapour and salt transmission. Life expectancy of 3 to 5 years. Helps reduce efflorescence. Mildew resistant. Non-flammable
A concentrated heavy duty alkaline cleaner. Excellent grout cleaner. Dissolves soap scum on tiles. Use on all types of tiles, slate and stone. To remove build up soiling and staining.
Spirit Neutral Cleaner
A fully biodegradable pH neutral cleaner safe for use on all surfaces that can be cleaned with water. Ideal for maintaining sealed terracotta, slate, marble and natural stone. Use as a routine daily cleaner to break down dirt and grease. Regular use will inhibit growth of algae or mineral deposits. Equally effective in hot or cold water.
Spirit Phosphoric Acid Cleaner
A concentrated heavy duty acid cleaner developed to remove cement, mortar and grout residue. It dissolves rust and hard water deposits, efflorescence and alkaline deposits. It has no harmful or damaging fumes which makes it much safer than muriatic acid.
Protectastone Product Profile
PROTECTASTONE is a hydrocarbon solvent-based silane/siloxane impregnant which has been formulated to impart excellent water repellency to a wide variety of natural building materials such as sandstone. The product is designed to penetrate into the first few millimetres of the surface and make the stone substrate water repellent. This water repellent zone dramatically reduces the absorption of water and water borne salts which is responsible for the bulk of the deterioration in natural stones such as sandstones. The water repellent zone will still allows the free passage of water vapour.
PROTECTASTONE is used to protect natural sandstone from the damage caused by weather and environmental damage.
PROTECTASTONE has been developed for optimum performance on the following sandstones: Debden, Warrego, Mt White/Somersby, Donnybrook, Wondabyne and Piles Creek.
As masonry materials vary, it is always recommended that a test must be carried out prior to application to find out the suitability of this product for the purposes. It is also important that the applicator should perform trials in a small scale before application.
- Penetrates deeply into masonry substrates. No peel or blister.
- Easy application.
- Excellent surface beading effect and stone remains cleaner.
- Does not significantly change the original surface appearance.
- UV and alkali stable formulation.
- Reduce water and chloride ion ingress by up to 95%.
- Reacts chemically with stone substrate to form a water repellent layer within the surface.
- Non-corrosive and non-toxic formulation.
- Appearance: Clear colourless liquid.
- Density (20 oC): 0.79g/ml
- pH value: N/a
- Solubility in water:Insoluble
Surface preparation The surface to be treated should be dry, firm and free from grime, oil, surface coatings and laitance. If the surface is dirty, the dirt should be removed by washing with water. Detergent should be avoided. However, a low residue and biodegradable detergent should be used and the detergent residues must be completely removed from the surface. The surface should be allowed to dry for a minimum 24 hours before application. All cracks grater than 0.3 mm should be filled. It is essential that the surface should be free of oily products and surface coating present before of PROTECTASTONE impregnation.