Naylor Hill Gritstone

Technical Data Sheet
Naylor Hill Gritstone
Naylor Hill Quarry
Dennis Gillson & Son (Haworth), Naylor Hill Quarries
Blackmoor Rd, Haworth, W. Yorkshire, BD22 9SU.
Contact : Dennis Gillson & Son (Haworth),
Email : [email protected]
Website : www.gillsons.com
Tel. 01535 643317
Grid Reference : SE 040 364
Compiled May 2000

This data sheet was compiled by the Building Research Establishment (BRE). It is based on data from current tests at BRE (2000). The data sheet was compiled in May 2000. The work was carried out by BRE as part of a Partners in Technology Programme funded by the Department of the Environment, Transport and the Regions and Gillson & Son (Haworth) Ltd and does not represent an endorsement of the stone by BRE.

General
Naylor Hill Quarry is a situated near Keighley has been in operation for 70 years with the saw works and quarry workings. The working face is some 20 m high. Quarried block sizes are up to 2 x 3 x 1.5 m. There are good reserves of stone.

Petrography
Naylor Hill Gritstone is a coarse grained yellow/ buff coloured Gritstone from the Millstone Grits of Carboniferous age.

Expected Durability and Performance
It is important that the results from the individual tests are not viewed in isolation. They should be considered together and compared to the performance of the stone in existing buildings and other uses. Sandstone is traditionally acknowledged as generally being a very durable building and paving stone and has been used extensively in many towns and cities in the UK. Naylor Hill gritstone appears to be a durable stone that has good resistance to acid rain or air pollution. In addition, the negligible weight loss in the sodium sulphate crystallisation test indicates good resistance to salt damage (for example in coastal locations or from de-icing salts) and should also have good frost resistance. The compressive and flexural strength of the stone is average for a sandstone. The density and compressive strength indicate that the stone has good abrasion resistance and should be suitable for use in heavily trafficked areas.

Overall, Naylor Hill Gritstone should be suitable for use in most aspects of construction including flooring, paving, load bearing masonry. The stone is suitable for areas where a long service life is needed. The stone is mostly used for paving and is not normally used for cladding.

Test Results – Naylor Hill Gritstone

Safety
in Use
Slip Resistance (Note 1)

81.9 

Wet. Values > 40 are considered
safe. 
Abrasion Resistance
(Note 1)

Not tested

Values <23.0 are considered
suitable for use in heavily trafficked
areas 
Strength
under load
1) Compression(Note 2)

101.0 MPa

Loaded perpendicular
to the bedding plane
ambient humidity
2) Bending (Note 1)

7.9 MPa

Loaded perpendicular to the
bedding plane
ambient humidity

Not tested

Loaded parallel to the
bedding plane
ambient humidity
Porosity
and Water Absorption
1) Porosity (Note 3)

9.6%

2) Saturation Coefficient (Note 3)

0.59

3) Water Absorption

2.4% (by wt)

4) Bulk specific gravity

2396kg/m3

Resistance to Frost 
Flexural
strength after
Freeze/Thaw Test (Note 1)

5.7 MPa

Loaded perpendicular
to the bedding plane
ambient humidity
Resistance
to Salt
Sodium Sulphate Crystallisation Test
(Note 3)

-0.57% Mean wt loss

Resistance to Acidity 
Acid Immersion Test(Note 4)

Pass

(Test methods Note 1 = EN1341, Note 2 = EN 1342, Note 3 = EN 1341 /BRE 141, Note 4 = BRE 141)

Tests were carried out at BRE in 2000

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