Cat Castle Sandstone (Buff)

Technical Data Sheet
Cat Castle Sandstone (Buff)
Deepdale, Barnard Castle, Co. Durham
Dunhouse Quarry Works, Staindrop Darlington,
County Durham DL2 3QU,England
Contact : Dunhouse Quarry Ltd
Tel. +44 (0) 1833 660 208; +44 (0) 1833 660 749
FAX +44 (0) 1833 660 748
Email : [email protected]
Web site :
Grid reference : NZ 010 164
Compiled May 2000

This data sheet was compiled by the Building Research Establishment (BRE). It is based on data from tests carried out by Sandbergs (1996), Stangers (1990), collated information from BRE and current tests carried out at BRE. 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 Dunhouse Quarry Co. Ltd and does not represent an endorsement of the stone by BRE.

The stone has been quarried in the Barnard Castle area since before the turn of the century. There are old quarries nearby which were owned by the railways and which provided stone for many of the railway bridges north of York. This particular quarry was closed in 1914 and reopened in 1977. The stone is marketed as Cat Castle Grey and Cat Castle Buff. There are good reserves of stone. The stone is extracted from a 4.5m face beneath 2m of overburden. There is thought to be further stone below the present floor of the quarry. The stone is available at various depths on bed and large blocks are obtainable.

Cat Castle is from the Coal Measures of Carboniferous age. It is an attractive coarse to very coarse grained stone, creamy buff in colour with darker specks though some blocks are grey in colour.

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 from the Coal Measures have been used extensively in many towns and cities in the UK. Cat Castle has a long history of use for buildings and civil engineering projects. Cat Castle sandstone appears to be a durable stone that is not effected by acid rain or air pollution. The weight loss in the sodium sulphate crystallisation test indicates resistance to salt damage but the high weight loss in the harsher saturated sodium sulphate test indicates susceptibility to salt damage in harsh environments (for example in coastal locations or from de-icing salts). Previous tests using the saturated sodium sulphate crystallisation test indicate that some caution is needed if the stone is to be exposed to a very harsh environment for a long period. In the frost test there is a slight loss in flexural strength with the Buff. However, the stones traditional use in the north of England and Scotland, including harbour walls, indicates good performance. The compressive and flexural strength of the stone is towards the lower end of the range for sandstone but is similar to some of the stronger limestones.

Overall, Dunhouse Buff should be suitable for use in most aspects of construction including load bearing masonry and cladding but special consideration may be required where extreme conditions are likely to be encountered.

Test Results – Catcastle – Buff

in Use
Slip Resistance (Note 1)


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

Not Tested

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

115.5 MPa
(94 – 115 Mpa range)

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


Loaded perpendicular to the
bedding plane
ambient humidity

Not Tested

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

(10.1 – 11.8 range)

2) Saturation Coefficient (Note 3)

(0.6 – 0.68 range)

3) Water Absorption

2.6 % (by wt)
(2.6 – 4.3 range)

4) Bulk specific gravity

(2350 –
2386 range)

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

5.2 MPa

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

-0.95% Mean wt loss

Sodium Sulphate Crystallisation Test
(Note 14) (saturated)

Mean: 82% wt loss

Resistance to Acidity 
Acid Immersion Test(Note 4)


(Test methods Note 1 = prEn1341, Note 2 = prEn 1342, Note 3 = prEn 1341 /BRE 141, Note 4 = BRE 141)

Tests were carried out at BRE in 2000

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