Sandstone: Characteristics, Uses And Problems
SANDSTONE: CHARACTERISTICS, USES AND PROBLEMS
This standard includes general information on the characteristics
and common uses of sandstone and identifies typical problems
associated with the material along with common causes of its
Characteristics of Sandstone:
- A sedimentary rock consisting of sheets of sand, mineral particles, and binding matrix deposited one
atop in water environments and desert formations.
- Very porous and water will penetrate it easily.
- Brown, red, purple, and pink sandstones are commonly called
- Available in a variety of surface textures and earth-toned
- Weathers best when its end-grain faces the weather (naturally
bedded). (Face-bedded) stone is subject to greater
deterioration. Water damages a face-bedded stone by spalling
or flaking off entire sheets of sandstone. Also, freeze/thaw
cycles allow water to get into the stone and then freeze and
expand causing some of the top layer to split off.
NOTE: In many 19th century applications, the grain was placed
parallel to the weather side (face-bedded) for aesthetic
reasons. This was especially common around doorways.
Typical historical uses for sandstone included:
- Urban row houses, commercial buildings and churches built from
the 1840s through the early 20th century (this was usually
brownstone); often fournd in Northeastern and Mid-Atlantic areas of the US.
- Lighter-colored sandstones were used more frequently by the
end of the 19th century.
Typical current uses for sandstone include:
- New sandstone is typically most often used for high quality custom-designed buildings. Such stone represents 13% of the dimension stone market (Mineral Information Institute). Also, new sandstone is used for restoration projects if appropriate.
PROBLEMS AND DETERIORATION
Problems may be classified into two broad categories: 1) Natural
or inherent problems based on the characteristics of the material
and the conditions of the exposure, and 2) Vandalism and human-
Although there is some overlap between the two categories, the
inherent material deterioration problems generally occur gradually
over long periods of time, at predictable rates and require
appropriate routine or preventive maintenance to control.
Conversely, many human induced problems, (especially vandalism),
are random in occurrence; can produce catastrophic results; are
difficult to prevent, and require emergency action to mitigate.
Some human induced problems, however, such as improper stone use, installations and details can be
mitigated with corrective treatments developed.
NATURAL AND INHERENT PROBLEMS
1. Moisture-related problems: May be evident in sandstone as
spalling, erosion, cracking, flaking and deteriorated mortar
2. Weathering: Disintegration of the stone's surface usually
caused by erosion, chemical action, and moisture freezing in
3. Exfoliation: Separation and loss of large areas of stone
along the bedding planes usually caused by the stone having
4. Blind Exfoliation: Separation of stone along bedding planes,
but where layers are still loosely attached behind the
surface. It is often caused by having laid the stone with the
bedding planes running parallel with surface of the wall
(face-bedding). Blind exfoliated stone will sound hollow when
lightly tapped with a rubber mallet.
5. Blistering: Swelling and rupturing of a thin uniform skin
caused by air-borne chemicals reacting with the stone's
surface, forming a hard, brittle skin. The blisters will
often pop when touched.
6. Cracking: Narrow fractures in the stone from 1/16 to 1/2 inch
7. Detachment: A clean break in the stone often resulting from
a sharp impact, or from stresses concentrated in a small area
of stone due to structural settlement.
1. Stone laid with its layers parallel to the wall plane (face-
bedded) rather than perpendicular to the wall plane
(naturally-bedded): Face-bedded stone is more prone to
deterioration by weathering as entire sheets of stone tend to
2. Painting over a deteriorated stone surface may lead
to more serious moisture-related problems when necessary treatment is deferred.
3. Applying a hard cement patch over deteriorated surface areas: If
an inappropriate patching mix is used, it may be necessary to
paint the entire stone surface to lessen the visual disparity
between the two materials, or remove the patch.
END OF SECTION