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Frequently Asked Questions
Architects/designers, contractors, engineers, conservators and building owners
have raised some interesting questions concerning its use here. We thought
you'd like to see our answers.
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P.J. Morrissey, October 2007
President, ConSpec Associates Inc.
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Architect/Designer
Where has Sandstone been used in the US?
It was used in 2003 at the Adult Training Center, Brooklyn NY, for the NYC Board of
Education, and is currently specified for several architectural and landscape projects
around the country, including a major restoration in Wilmington DE, and outdoor
seating at the University of North Carolina at Chapel Hill.
What color is it?
Sandstones can vary from a deep brown, to deep red. Sandstone is quarried in two
colors, a reddish-brown and a yellow-buff. Each exhibits the slight sparkle that is
typical of quartz sandstones. These earth tone colors can be used to create complex
designs that are resistant to severe weathering conditions, including ground contact.
What sorts of finishes are available?
Sandstone is available in all the traditional finishes, such as natural cleaved,
sawn, sandblasted, and rock-faced. Some sandstones are remarkably tough and
compact and can also be flame finished or polished.
Contractor
How soon can it be delivered?
Delivery can be approximately six to eight weeks after receipt of your order. For larger
shipments, there may be some normal delays associated with winter shutdown of the
quarries.
Can it be delivered carved, and how long would that take?
If you supply detailed shop drawings, carving can be accomplished at the quarry. This
does not add substantial time to your construction schedule.
In what sizes is it available?
The quarry is currently sawing blocks up to 8 feet in length. It is sold in a wide range
of sizes as ashlar units, paving (flagging and blocks), and special items, such as
decorative fountains, benches and outdoor sculpture.
Engineer
How strong is it?
Brownstone has a crushing strength of about 19,000 psi; it is thus one of the strongest
sandstones in the world.
How long has it been in use?
It has been utilized in Northern Europe for the construction of castles, fortifications and
public buildings since at least the early 13th century. From the 18th century onward, it
is seen in some unusual situations, including street paving, garden walls, and the lining
of canals, where it has proved to be of outstanding durability.
Conservator
What is the weathering performance of Sandstone?
Buff and brown Sandstone has historically been used in North Germany and
Russia, where the climate is similar to New England and parts of eastern Canada. The
current condition of structures and monuments of stone from the Bad Karlshafen
quarries is excellent. Carving and lettering are still sharp and legible after hundreds of
years.
Have there been any laboratory investigations to support claims of resistance to
environmental acidity and freeze/thaw?
Sandstone has excellent freeze/thaw characteristics; recent studies on 1” cubes
have shown no failures at 100 cycles. (Indiana limestone typically fails at 60 cycles in
this test.) It does not exhibit any reactivity when tested with 0.1 M sulfuric acid. Many
commercial sandstones being sold today do react with acid, some vigorously.
Building Owner
I've always wanted to use real sandstone. How does it compare in price with other
materials?
Natural stone is always more expensive than substitute materials, such as stucco or
artificial stone. However, this initial cost does not reflect the greater service life of
stone and its considerable positive effect on resale value.
Wouldn't the cost of importing from Europe be prohibitive?
Freight charges are actually a relatively minor factor. For both architectural and paving
stone, it is the costs of quarrying, cutting and finishing that are the principal
determinants of selling price.
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© 2008 ConSpec Associates, Inc.
(203) 467 4426
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