| Limestone Applications:
The Irish Blue Limestone is available in four
different grades. The classification process excludes specific flaws that could result in
premature failure of the limestone in service and grades on the basis of surface
appearance. Although primarily aesthetic, the grading will also define the suitability of
Irish Blue Limestone for applications.
The highest grade is monumental stone. This is a very uniform limestone with few
surface imperfections. These properties make it ideal for carving and limestone of this
class can hold very fine detail when used in sculpture, headstones, plaques, or ornamental
features. The stone will develop a deep lustrous polish.
All the quarries have horizons that yield monumental grade
limestone although the proportion available relative to overall production may vary.
Class A and Class B limestones are primarily building
stones. Class A stone is normally specified for prestige building or restoration work or
where a fine consistent polished or blue-honed surface is required. The Class A stone
would also be suitable for plinths or kerbing surrounding graves.
Class B limestone is normally used for cladding and ashlar
work in the building industry. Where the stone is to be used in continental Europe, it is
essential that this is the minimum specified grade to avoid problems of premature surface
failure. It should normally be specified for the more extreme conditions in Ireland. The
stone will take a honed or polished finish and although occasional minor surface
imperfections may be visible, they will not seriously detract from the overall appearance
of the stone.
The run of production stone is suitable for use as kerbs,
paviors and setts in continental Europe. Where the limestone will not be exposed to
extreme conditions, cladding or ashlar meeting this grading specification will be suitable
for use in Ireland. The stone will accept honed or polished finishes but may show surface
imperfections. Where the stone is unlikely to be seen close up, this may be quite
acceptable for many applications.
By selection of the correct grade of Irish Blue Limestone,
the material can be used in an extremely wide range of applications. The table on the
following page illustrates the versatility of the limestone.
| Application |
Components |
| Urban Environment |
Footpaths / Kerbs / Walling / Street Furniture |
| Construction |
Vertical Elevations / Cappings and Copings / Sills and
Lintels / Plinths and Foundations / Harbour Walls / Bridge Piers |
| Cladding |
Internal / External |
| Flooring |
Internal / External |
| Staircases |
Internal Panels / External Panels / Treads |
| Decorative |
Fireplaces / Door and Window surrounds / Table and Counter
Tops |
| Monumental |
Sculpture / Gravestones and Kerbs |
Manufacturing Accuracy and
Tolerances
Irish Blue Limestone will have to be cut to size at a number of stages
during processing. Any processing operation can result in some inaccuracies and this
may be compounded by the inherent variations in any natural material. Diligent
checking of dimensions at all stages during the processing however, does guarantee that
the Irish Blue Limestone deleivered to the customer will comply with the specification for
that application. The dimensional tolerances given are those roughly achieved during
production. The values in brackets [ ] are achievable if required. |
| Sawn
Slab |
| Area: |
Maximum regular rectangle that could be cut from the slab.
Dimension tolerance + / - 10mm.
An allowance of 20 millimetres will be made on length and width for subsequent processing
losses. |
| Where the slab has a single surface flaw or an
unacceptable stylolite or white vein it may be supplied, subject to agreement, with an
area based on the amount of unusable limestone. |
| Thickness: |
As per finished stone |
| Bow or Twist: |
As per finished stone |
| Finished
Stone |
| Cladding,
Contra-pass, Sawn Ashlar |
Length &
Width: |
+ 1.0mm for dimensions up to 700mm
+ 2mm [+ 1.5mm] for dimensions equal to or greater than 700mm |
| Thickness: |
+ 2mm |
| Squareness: |
+ 1.5mm [+ 0.5mm]for lengths less than or
equal to 1000mm
+ 2mm [+ 0.5mm per 1000mm] for lengths greater than 1000mm |
| Cladding
Only |
| Bow / Twist: |
Sawn face panels + 1.5mm per 1200mm of the length
of the longest edge.
Ground face panels + 1.5mm per 1000mm [+ 1.0mm per 1000mm] of the length of
the longest edge. |
| Split Face: |
Thickness + 7.5mm |
| Curved,
Ornate or Complex Ashlar Only |
| Shape: |
Template dimensions + 1.5mm with butting faces
matched as necessary. |
| Split
and Dressed Ashlar |
Length &
Width: |
+ 2mm [+ 1.0mm] for dimensions up to 700mm
+ 2mm [+ 1.5mm] for dimensions equal to or greater than 700mm |
| Thickness: |
+ 10mm [+ 7.5mm] |
| Rustic
Paviors and Sets |
Length &
Width: |
Sawn sides + 3.0mm
Guillotined sides + 7.5mm |
| Thickness: |
+ 10mm [+ 7.5mm] |
| Tiles |
Length &
Width: |
+ 0.5mm |
| Thickness: |
+ 0.5mm |
| Monumental
Limestone |
| Length: |
+ 6mm / -3mm |
| Thickness: |
+ 3mm
Note: Posts + 3mm |
| The tolerances outlined above
do not include allowable tolerances on applied labours such as chamfered, bullnosed or
bevelled edges, rebates etc. Details of these should be checked with the individual
producers when the original specification is being prepared. |
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