This data sheet was compiled by the Building Research Establishment (BRE). It is based on data from collated BRE data and 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 Viva Properties Ltd. and does not represent an endorsement of the stone by BRE.

General
Callow Hill Quarry is near Monmouth, Herefordshire. The stone is extracted from two faces and supplied as walling stone and block stone. There are no saw works. The stone is available in depths of 0.3 - 2 m on bed. There are good reserves of stone.

Petrography 
Callow Hill sandstone is a fine grained, red/brown coloured sandstone from the Old Red Sandstone of Devonian 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. Callow Hill sandstone appears to be a durable stone despite having limited resistance to acid. Some care is required in the selection of the material as the acid immersion results are variable indicating that there is some variation in the deposits. It has been used successfully in non-industrial applications in the locality. In addition, the negligible weight loss in the sodium sulphate crystallisation indicates good resistance to salt damage (for example in coastal locations or from de-icing salts). From the frost test the stone should also have high frost resistance. The compressive and flexural strength of the stone is high for a sandstone. The high flexural and compressive strength indicate that the stone should be suitable for use in heavily trafficked areas.

Overall, Callow Hill should be suitable for use in most aspects of construction including flooring, paving, load bearing masonry and cladding. Special consideration is required for areas where there is the likelihood of encountering an acidic environment and a long service life is required. Traditionally the stone has been used for walling and block work.

Test Results - Callow Hill

Safety in Use
Slip Resistance (Note 1)	72	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)	153.4 MPa	Loaded perpendicular to the bedding plane ambient humidity
2) Bending (Note 1)	18.4 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)	9.7%
2) Saturation Coefficient (Note 3)	0.65
3) Water Absorption	2.6 % (by wt)
4) Bulk specific gravity	2435kg/m3
Resistance to Frost
Flexural strength after Freeze/Thaw Test (Note 1)	16.1 MPa	Loaded perpendicular to the bedding plane ambient humidity
Resistance to Salt
Sodium Sulphate Crystallisation Test (Note 3)	-0.48% Mean wt loss
Resistance to Acidity
Acid Immersion (Note 4)	Fail (2000) Pass (1993)

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

Back to top of page | Back to stone list