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INTRODUCTION The versatility of natural stone">stone is well illustrated in its application as stair treads, window cills, wall copings and cappings. It allows the potential for continuity of a theme, or alternatively may be used as a feature amongst other materials. Unlike many stone">stones Kirkstone">stone and Brathay may be used both internally and externally as they are not susceptible to frost due to their extremely low porosity. STAIRS When selecting stone">stone for use on a stair, equal consideration must be given to visual appearance, the structure of the stair that will support the treads, and safety in use. Kirkstone">stone and Brathay are materials laminated by nature and thus offer high degrees of lateral strength. This enables them to be used in relatively thin sections even on open tread designs. In general, treads bedded onto a framed stair should be 30mm thick which will provide sufficient strength to permit an overhang to the riser. It also allows sufficient thickness to add grooves or a recess for an anti-slip inset. Thinner stone">stone may be used for the risers or on the treads, but if it is less than 20mm thick restriction on stone">stone sizes will result in a "tile effect" stair. Kirkstone">stone can offer a variety of nosing details as illustrated below (Diagram 1). These can help to prevent slipping on the tread and also act as a visual definition to the tread edge.
CILLS AND THRESHOLDS Natural stone">stone is still regarded as one of the best materials for use as an external cill to a window or door threshold. Eminently durable, the aesthetic appeal of stone">stone can provide an excellent contrast to brickwork, render, ashlar etc. As with copings they are available in a variety of finishes depending on the stone">stone selected and can be sawn to any shape or size, up to a preferred maximum of 1500mm long. Typical details are shown below (Diagrams 2 and 3). In general, the sawn underside face provides a surface that is sufficiently keyed for bonding. Where it is felt necessary, serrations for added bond strength can be produced.
COPINGS Copings can be produced for both internal and external use in a variety of finishes to the exposed face. Seen edges can be left as sawn, or honed smooth. If a more rugged finish is required to the edge please consult Kirkstone">stone for advice on what finishes are possible. Virtually any shape or size of coping can be produced but for ease of handling, lengths should ideally be kept below 1500mm. Internal and external mitred joints can be accommodated where necessary. Two typical details are shown below (Diagrams 4 and 5). In general, bonding the coping onto the wall using an adhesive or cement mortar will supply sufficient anchorage. Additional security can be provided by dowelling individual copings either directly to the wall or all together to create the mass of one large coping. In highly exposed areas subject to heavy use further mechanical fixing may be required to ensure structural integrity with the supporting wall. |
Stone Identification