Mint sandstone

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[edit] Introduction

Mint Sandstone is a commercially used natural sandstone characterised by light buff, beige and pale yellow tones, sometimes with greenish or greyish variations. Like other natural stone products, its colour, texture and physical properties can vary between individual pieces and batches. The suitability of Mint Sandstone for a particular application depends on its tested characteristics, finish, dimensions and the requirements of the proposed use.

The term Mint Sandstone is primarily a commercial description rather than a precise geological classification. Products sold under this name can therefore differ in geological characteristics and performance. Technical information for the particular stone should be obtained when the material is being specified for construction.

[edit] Characteristics and appearance

Sandstone is a sedimentary rock formed from sand-sized mineral particles that have been deposited, compacted and cemented together. Quartz is commonly a major constituent, although the precise mineral composition varies between sandstones.

Mint Sandstone generally has a relatively light appearance, with combinations of buff, beige, pale yellow and occasionally greenish or grey tones. Natural variation is an inherent characteristic of sandstone, so individual slabs or paving units are unlikely to be identical. Where colour and texture are important to a project, representative samples or a control range should be examined rather than relying on a single sample.

The surface finish can also affect the appearance and performance of the stone. Natural or riven finishes retain more of the surface texture, while sawn and honed finishes provide a flatter and more uniform appearance. Other finishes may be available depending on the characteristics of the particular stone.

[edit] Applications

Mint Sandstone may be used for a range of construction and landscaping applications where its physical properties are suitable. These can include:

• external paving, patios, paths and courtyards;
• steps and other landscape features;
• walling and copings;
• building facades and natural stone cladding;
• internal flooring and other interior applications; and
• architectural and decorative features.

Applications subject to significant loading require particular consideration. For example, stone suitable for pedestrian paving should not automatically be assumed to be suitable for vehicle traffic. The required thickness and construction depend on the physical properties of the stone, the dimensions of the paving units, the supporting construction and the expected loading.

Natural stone cladding also requires appropriate consideration of the fixing system and the weight of the stone. Thin stone used as cladding is generally supported and fixed to the structural substrate by a suitable mechanical or proprietary system rather than being treated as structural masonry.

[edit] Selection and specification

The selection of Mint Sandstone should begin with the intended application and the environmental and loading conditions to which the stone will be exposed. Relevant properties can include water absorption, density, flexural strength, compressive strength, resistance to abrasion, frost resistance and slip or skid resistance, depending on the application.

The required dimensions and thickness should be established from the proposed use and the tested characteristics of the particular stone. There is no single thickness that is suitable for all paving, cladding or other applications.

The surface finish should also be specified. Surface texture can affect appearance, cleaning requirements and slip performance. Where slip resistance is important, the performance of the actual stone and finish should be established through appropriate testing rather than inferred solely from descriptions such as 'natural' or 'riven'.

Natural colour variation should be considered during specification and installation. For significant projects, slabs or paving units from different batches should be assessed to establish the expected range of colour and texture.

[edit] Installation and maintenance

The performance of Mint Sandstone depends on the complete construction in which it is used, as well as the properties of the stone itself. For external paving, the supporting ground, sub-base, bedding, joints and drainage should be designed for the expected loading and site conditions. Paving should generally be laid to appropriate falls to prevent prolonged standing water.

The laying method should be appropriate to the paving units, substrate and intended use. Joints and bedding should form part of the overall paving design rather than being selected solely according to the nominal dimensions of the stone.

Sandstone is a porous natural material and can absorb water and contaminants. Regular sweeping and appropriate cleaning can help maintain its appearance and reduce the accumulation of organic matter. Cleaning products should be suitable for the particular sandstone and finish. Strongly acidic or otherwise aggressive cleaning agents can damage some stone surfaces and should not be used unless their suitability has been established. Excessive pressure washing can also damage some finishes.

Sealing is not universally required. Where a sealer is used, it should be selected for the particular stone, finish and intended application. Sealing does not compensate for inadequate drainage, unsuitable installation or inappropriate stone selection.

[edit] Related articles on Designing Buildings

• Natural stone
• Types of stone
• Natural stone paving
• Natural stone flooring
• Natural stone cladding
• Types of cladding
• Autumn Brown Sandstone
• Sandstone.