slide 1 masonry - atlanta preservation and planning...

Masonry

Stone, Brick, Concrete, Terracotta, Adobe,

Tabby [Plaster & Stucco]

Richest and most varied building material with endless colors, textures, and patterns.

Slide 2 STONE

Oldest building material Simplest building technique — stacked stone Most expensive

– Traditionally, large public buildings built of stone– Less often used for residential buildings, except

for facing or decoration.

The high cost of transporting stone meant that it was advisable to use local stone

Slide 3

Sphinx, ca. 2500 BCE. Carved out of limestone outcrop. Granite facing

applied later.

Egypt’s first pyramids ca. 3000 BCE. Built mostly from limestone; other stones used on interior.

Pyramids: interior stones include low grade limestone at the core; fine white limestone for the outer casing; pink granite for the interior walls which had to withstand more stress; also basalt and alabaster. The casing stones were removed about 1300. What you see today is about 700 years of weathering in a dry climate.

Great Wall of China, 7th-6th Centuries, BCE

Sandstone, rammed earth, brick

Longest human-made structure, approx. 3,948 miles

Slide 5

Parthenon, Athens, Greece, 447-432 BCE. Marble and limestone

Slide 6 Colosseum, Rome

Vespasian, 70-82 CE

Concrete and tufa faced with travertine

Tufa is a soft, porous CaCO3 limestone from ambient temperature bodies of water. Do not confuse with tuff—an igneous rock composed of compacted volcanic ash. Travertine is limestone deposited from solution in hot, freshwater springs, aka flowstone. There are extensive deposits of travertine at Tivoli, Italy.

Taj MahalAgra, India 1630-1653 Marble

Slide 8

http://3dparks.wr.usgs.gov/nyc/common/geologicbasics.htm

Slide 9 How to Distinguish Rocks Lightness / Darkness Coarseness / Fineness

– Are the grains visible?

Gabbro

Rhyolite

Basalt Granite

Gabbro is a dark, coarse-grained, plutonic igneous rock. It is the chemical equivalent of basalt—a fine-grained volcanic igneous rock which cools too quickly for large mineral crystals to grow. The vast majority of the earth’s surface is underlaid by gabbro. Granite is a light, coarse-grained, plutonic igneous rock. It is the chemical equivalent of rhyolite, a fine-grained volcanic igneous rock.

“Granite” Countertops?

Marketing claims aside, these countertops are

andesite

Drummond kitchen. Andesite is a volcanic igneous rock, the extrusive equivalent of plutonic diorite.

Slide 11 How not to Distinguish Rocks Not by color: color often comes from

impurities in the rock– Greens — chlorites, magnesium– Reds — iron oxides, esp. hematite (iron ore)– Yellows/tans — hydrated iron oxides

Chlorite Iron Ore Limonite

Slide 12 Igneous — rock deposited in a molten state

Plutonic — formed deep beneath earth’s surface, when magma cools & hardens– Granite (light); diorite (dark); gabbro (very dark,

mistakenly called black granite)– Granite: “grain”-y, non-porous, light colored (gray to

pink), hard, durable, scratch- and chemical-resistant, takes a variety of finishes, low thermal expansion, can be used in contact with the ground or exposed to severe weathering

Volcanic — formed close to the earth’s surface when lava cools & hardens– Rhyolite, andesite, basalt, pumice, tuff– Not often used for building in U.S. — few volcanoes

Slide 14 Boston Public Library

Pink granite; 1888-1895; McKim, Mead & White

Slide 15 Rhodes Hall — 1516 Peachtree Street NW; Stone Mtn. granite and Lithonia gneiss;

1904; W. F. Denny, II

http://archive.rebeccablacktech.com/boards/cgl/img/0059/49/1339713678612.jpg Rhodes Hall in midtown Atlanta, built of both Stone Mountain Granite and Lithonia Gneiss http://georgiarocks.us/gallery/AtlantaQuarriesCuts/AtlantaQuarriesCuts-Pages/Image4.html

Stone Mountain, GA, ca. 1916

http://dbs.galib.uga.edu/cgi-bin/ultimate.cgi?dbs=vanga&ini=vanga_galileo.ini&userid=galileo&_cc=1 Vanishing Georgia DEK-4

Slide 17

Anisotropic – directionally dependent– Specific bedding planes– Sandstone and limestone are examples

Sedimentary — rock deposited on the earth’s surface by the

action of wind and water

Isotropy – identical properties in all directions Wood is also anisotropic—easier to split along the grain than against it

Slide 18 Sandstone Crossbeds

Red Rock Canyon National Conservation Area, 17 miles west of Las Vegas strip. About 180 million years ago the area was completely arid, much as the Sahara Desert is today. A giant dune field stretched from this area eastward into Colorado, and windblown sand piled more than half-a-mile deep in some spots. As the wind shifted the sands back and forth, old dunes were leveled and new ones built up leaving a record of curving, angled lines in the sand known as "crossbeds". These shifting sands were buried by other sediments, and eventually cemented into sandstone by iron oxide with some

calcium carbonate. This formation, known locally as the Aztec Sandstone, is quite hard and forms the prominent cliffs of the Red Rock escarpment. In some areas the iron minerals in the rocks have been altered and concentrated giving the rock it's red color. http://www.blm.gov/nv/st/en/fo/lvfo/blm_programs/blm_special_areas/red_rock_nca/red_rock_s_unique/red_rock_geology.html

Slide 19 Sandstone Crossbeddingand Jointing

Checkerboard Mesa is a mass of slickrock with crossbedding etched into the north face of the rock. The imperfect vertical and horizontal fissures are a result of jointing and crossbedding. The checkerboard design has been created by weathering and erosion in the upper portion of the Navajo Formation. Weathering by rainwash and freeze-and-thaw cycles brings these grooves out in relief.

Slide 20

Carbonates: CaCO3 and Mg(CO3)2

– Composed of carbonate minerals which precipitate out of supersaturated waters, or are formed when the water evaporates

– Limestone, travertine, tufa are precipitates– Oolitic limestone, gypsum are evaporates– Porous; will not accept a high polish; soluble

in acid; very absorbent and susceptible to staining not usually in contact with soil

1st Sedimentary Rock Type

There are two types of sedimentary rocks: carbonates and silicates. We’ll look at carbonates first. Chemical sedimentary rock forms when mineral constituents in solution become supersaturated and inorganically precipitate. Common chemical sedimentary rocks include oolitic limestone and rocks composed of evaporite minerals such as halite (rock salt), and gypsum. Most other limestone, and travertine and tufa are evaporates. Oolitic limestone is also found in Indiana in the United States. The town of Oolitic, Indiana, was founded

for the trade of limestone and bears its name. Quarries in Oolitic, Bedford, and Bloomington contributed the materials for such iconic U.S. landmarks as the Empire State Building in New York and the Pentagon in Arlington, Virginia. Many of the buildings on the Indiana University campus in Bloomington are built with native oolitic limestone material, and the Soldiers' and Sailors' Monument in downtown Indianapolis, Indiana, is built mainly of grey oolitic limestone. The 1979 movie Breaking Away centers around the sons of quarry workers in Bloomington. Oolitic refers to the ooids from which the rock is formed—spherical grains made of concentric layers. Comes from the Greek word for “egg”. Pronounced Ho-olitic (long o’s).

Slide 21

Tufa — Ostia, 1st

century BCE

Travertine — LA, 1984-1997

Getty Centre in Brentwood, LA; Richard Meier & Partners, architects (1984-1997); concrete and steel with either travertine or aluminum cladding; 1.2 million square feet of travertine used to build the centre. Image from: http://www.archdaily.com/103964/ad-classics-getty-center-richard-meier-partners-architects/96sf20-163/ Tufa stone work (NOT bricks) from the Ostia Synagogue (1st European synagogue discovered; dates between 1st century BCE and 1st century CE), in the city of Ostia, the harbor of Rome at the mouth of the Tiber River. Image from: http://www.utexas.edu/research/isac/web/OSMAP/OSMAP_Masonry2.html

Tufa

Towers, Mono

Lake, CA

“Tufa” – a sedimentary rock...

The most iconic visual feature of Lake Mono are tufa towers formed by underwater springs rich in ionized calcium; these calcium rich waters mix with high carbonate lake waters, producing deposition of calcium carbonate. Since the formation only occurs underwater, the emergent towers testify to the decline in surface level since 1941, the date when massive water diversions to the rapidly expanding human population of Southern California commenced. Top image from: http://www.oceanlight.com/spotlight.php?img=09931 Bottom right image from: http://www.grahamowengallery.com/photography/landscape_CA_inland.html

Slide 23 Not to be confused with

“Tuff” – an igneous rock

Tuff buildings, Kirkland, AZ, ca. early 1900s

Tuff columns, Pompeii forum, pre-79 CE

Two tuff buildings in Kirkland, AZ: http://walkingprescott.blogspot.com/2010/03/back-in-outback2-kirkland.html Tuff columns along the forum in Pompeii: http://www.flickr.com/photos/roger_ulrich/6057894758/ (Note modern concrete bases)

Georgia Capitol — Atlanta; Indiana ooliticlimestone; 1889; Edbrooke & Burnham

Slide 25

Manufacturer and Builder, XIX, 11 (Nov. 1887), 253.

http://ebooks.library.cornell.edu/cgi/t/text/pageviewer-idx?c=manu;cc=manu;rgn=full%20text;idno=manu0019-11;didno=manu0019-11;view=image;seq=0258;node=manu0019-11%3A37

Slide 26 Georgia Capitol, West Exterior Stairs

Bottom step is granite; other stairs are limestone. Limestone is porous, will not accept a high polish, soluble in acid, high absorption and susceptibility to staining not usually in contact with soil. Granite is more impervious to water and has great compressive strength, making it ideal for foundations.

Silicates: SiO2 (quartz) + Fe2O3 or CaCO3

– Composed primarily of silicate minerals transported by moving fluids, and were deposited when the fluids came to rest

– Sandstone (brownstone & bluestone are colored sandstones)

– Highly stratified, durable good for paving, sills, hearths, mantels, copings

2nd Sedimentary Rock Type

Slide 28

The White House; Washington, DC;

sandstone façade over brick; 1798; James

Hoban

1858 view to northwest showing west side and south porch. http://lcweb2.loc.gov/service/pnp/cph/3b30000/3b32000/3b32800/3b32885r.jpg

Slide 29 Changes to the White

House

1948-1952: President Truman gathered engineers and architects together to study the condition of the White House. They found that the house needed an enormous amount of work in order to save it. The president wrote to a congressman: "My suggestion is that we do not tear down the present building. The outside walls are in good condition . . . . We could put a steel and concrete structure inside the walls and restore the inside of the house to its original condition. We are saving all the doors, mantels, mirrors and things of that sort so that they will go back just as they were.“The outer walls — the

same walls that James Hoban built — were saved, and so was the third floor. Otherwise, the entire interior was taken down. Bulldozers moved in and dug down two additional basement levels to provide more storage room and space for heating and air conditioning equipment. The White House was also fireproofed. The size and shape of the first and second floor rooms were rebuilt to appear as they did throughout the building’s history. This work took four years to complete. The Truman family moved across the street to Blair House. In 1952 the work was done, and the first family moved back to the White House. The President’s House was stronger, safer, and ready to serve the nation’s leader for years to come, and the image of the White House never changed.

Slide 30

Changes to the White

House

2011-2014: Utilities construction April 4, 2011; not due to be complete until 2014. Of course, there are also rumors of new secret tunnels and bunkers beneath the White House. But GSA officials insist it is a project devoted just to utilities, including new lines for water, sewer and electricity.

Austin Hall, Harvard University Law School Cambridge, MA; red sandstone; 1881-1884;

H. H. Richardson

Slide 32 Mount Airy, Warsaw, Virginia, 1758; dark brown sandstone, trimmed in light-colored sandstone,

projecting limestone pavilion; John Ariss (?)

Slide 33 Connecticut

brownstone used to build the New

York Brownstones

Brownstone Architectural

Details

Italianate school with rusticated brownstone first floor, decorative window hoods (pediments and arches), brownstone window sills, Originally PS 16, built in 1869 at 208 West 13th Street in northern Greenwich Village. Additions, with pediments, built in 1879 with bracketed pediments, brownstone keystones and imposts, arched windows. Became a vocational school of various types throughout 1920s-1970s. The Lesbian & Gay Community Services Center, Inc. purchased the old school building from the City’s Board of Estimates in December 1983 for $1.5 million. Architect Francois Bollack was commissioned to restore and convert the school building into the Center which is used today by at least 300 groups. Images from: http://daytoninmanhattan.blogspot.com/2012/08/ps-no-16-lgbt-community-ctr-no-208-west.html

Slide 35 Bluestone —used for

coping and flagging

Bluestone wall coping and patio: http://www.bedfordstone.com/products/walls-&-coping/368/photo/370/ Inground Gunite pool, bluestone coping, Mikonos pavers, raised water all of PA fieldstone veneer: http://www.poolrenovationsnj.com/portfolio/swimming-pool-renovations-nj/suffern-ny/#!prettyPhoto[pp_gal]/1/ Bluestone coping on limestone wall: http://www.charlesluck.com/products/shoreline-buff Bluestone mantel: http://www.log-cabin-connection.com/fireplace-mantel.html

Terrigenous—derived from the erosion of rocks on land

Slide 37 Metamorphic Rock — formerly igneous or sedimentary rock, transformed by

heat and/or pressure

Three Main Types: Gneiss, Slate, Marble

Slide 38

–Gneiss: formed from igneous or sedimentary rocks Very hardGood for foundations, walls, & other load-

bearing applications

–Slate–Marble

Types of Metamorphic Rocks

Washington Hall,

U.S. Military Academy, West

Point, NY; gneiss

Rock-faced, random ashlar

Slide 40 Morton Gneiss

Stone is about 3.5 billion years old; quarried in Morton, MN since 1884

Dated to 3.5 billion years old, one of oldest stones in the world. Quarried in Morton, MN since 1884. The Morton Gneiss was widely used for buildings and monuments. It was highly valued for its swirling color patterns and great age. Because of the difficulty of extracting large, coherent blocks, it was expensive to produce compared with many other conventional granites and marbles. For these reasons, it commanded a high price in the commercial stone market. Morton Liquor store image: http://stories-in-stone.blogspot.com/2009/06/most-beautiful-building-stone-in.html The building was originally a mercantile built by JH McGowan and RB Hinton in the 1890s. Historic photo: http://stories-in-stone.blogspot.com/2010/03/morton-liquor-update.html

2010 Update

2010 Morton Pub & Eatery image: http://stories-in-stone.blogspot.com/2010/03/morton-liquor-update.html

Slide 42 McDonald’s at Redwood Falls, MN

Architectural use of Morton

gneiss

Morton gneiss sink at the Redwood Falls, MN McDonalds (about 7 miles away from Morton, MN, where the famous Morton Gneiss is quarried). Images: http://stories-in-stone.blogspot.com/2010/02/gneiss-and-mcdonalds.html

Slide 43

Morton, MN Gneiss Quarry

Wedges used to break blocks along closely spaced drilled holes. Wedge quarry image: http://academic.emporia.edu/aberjame/tectonic/morton_gneiss/morton05.jpg Vertical cylinders were drilled to lower wire saws for cutting flat faces in the quarry walls. Cylinder quarry image: http://academic.emporia.edu/aberjame/tectonic/morton_gneiss/morton08.jpg

Peachtree Center MARTA Station —carved out of solid gneiss

Peachtree Center station is the deepest station in the MARTA rail system, at 120 feet or 36 meters below Peachtree Street. The walls and ceiling are carved out of solid gneiss rock. The length of the main hall is 900 feet. The Carnegie Way/Ellis Street escalator is 190’ long, one of the longest escalators in the Southeast. http://farm3.staticflickr.com/2066/2275120367_5eaf733899_z.jpg?zz=1 http://collections.atlantahistorycenter.com/export/get_item_viewer_image.php?alias=/Stupich&i=15&height=600&width=600 ca. 1977

Slide 45 Gneiss in the Atlanta Area

Clairmont Road at I-85

I-285 east of GA 400

A block of amphibolite surrounded by gneiss in the Clairmont Formation at Clairmont Road and I-85. http://georgiarocks.us/gallery/AtlantaQuarriesCuts/AtlantaQuarriesCuts-Pages/Image2.html Mylonitic Long Island Gneiss exposed along I-285 east of GA 400. http://georgiarocks.us/gallery/AtlantaQuarriesCuts/AtlantaQuarriesCuts-Pages/Image11.html

Slide 46 Granite vs. Gneiss

Granite is a plutonic igneous rock. Its crystals form differentially upon cooling deep in the earth's crust. Granite’s visible crystals are randomly arranged.

Gneiss is a metamorphic rock that shows obvious banding of light and dark minerals resulting from recrystallization of the original material due to high heat and pressure.

If you can discern a pattern, it's not granite!

http://www.scottranger.com/geology-of-arabia-mountain.html

Arabia Mtn. gneiss among the granite

http://www.scottranger.com/uploads/2/9/6/0/2960231/8732807_orig.jpg

Slide 48 Arabia Mountain Migmatitic Gneiss“Tidal Gray”

http://www.scottranger.com/uploads/2/9/6/0/2960231/5375396_orig.jpg

Slide 49 Atlanta Area Rock Outcropsgeorgiarocks.us

Rock outcrops, numbered in the order mentioned in the "Around Atlanta - Quarries and Roadcuts" section of Roadside Geology of Georgia - from Google Earth http://georgiarocks.us/gallery/AtlantaQuarriesCuts/AtlantaQuarriesCuts-Pages/Image0.html

Distribution of Granites & Gneisses in Georgia from quarriesandbeyond.org

http://quarriesandbeyond.org/states/ga/images/ga-granites-gneisses_1902_map_p_88_distrib_of_georgia.jpg Georgia - Map Showing the Distribution of the Granites and Gneisses of Georgia, from A Preliminary Report on a Part of the Granites and Gneisses of Georgia, Bulletin No. 9-A, by Thomas L. Watson, Ph.D., Assistant Geologist, Geological Survey of Georgia, 1902, pp. 88.

Slide 51 Vulcan Materials Gneiss Quarry, Norcross, GA

A quarry truck more than 15 feet high carries a load of gneiss out of Vulcan Materials Norcross Quarry, one of the largest quarry operations in the country. http://georgiarocks.us/gallery/AtlantaQuarriesCuts/AtlantaQuarriesCuts-Pages/Image1.html

Slide 52

–Gneiss–Slate: formed from shale (sedimentary

rock) Very dense and hardGood for paving stones, roof shingles, water courses, and countertops

–Marble


Slate

Slide 54 Pentagon,

Arlington, VA, ca. 1943, George

Bergstrom

September 11, 2001 attack

destroyed more than an acre of the slate roof.

Slide 55

Slate-bearing

formations in Georgia

http://quarriesandbeyond.org/states/ga/images/ga-rpt_slate_deposits_ga_p42_map_i_distrib_slate-brng_forms.jpg Georgia - Index Map Showing the Distribution of Slate-bearing Formations in Georgia (circa 1918), from Report on The Slate Deposits of Georgia, Bulletin No. 34, by H. K. Shearer, Assistant State Geologist, Geological Survey of Georgia, 1918, pp. 42.

Gneiss– Slate– Marble: recrystallized limestones

(sedimentary), easily carved and polished Carrera and Vermont marble — grains are

smaller, more porous, metamorphic process did not go as far, chisel can go through it cleanly finely detailed carving, more susceptible to deterioration, especially granular disintegrationGeorgia marble — larger grained, stronger, used

as foundation stone


Slide 57 Taj Mahal; Agra, India; 1630-1653;

marbles

Slide 58 Candler Building

127 Peachtree Street NE; 1906;

George E.Murphy, architect;

F. B. Miles, sculptor; Georgia marble from the

Amicalola quarries in Pickens County

Atlanta, Georgia - the Candler Office Building - the Entrance, from A Preliminary Report on the Marbles of Georgia, Bulletin No. 1, by S. W. McCallie, Assistant State Geologist, Geological Survey of Georgia, 2nd ed., 1907, pp. 120. Built by Asa Griggs Candler, Coca-Cola magnate. 17 stories high; at time, tallest building in Atlanta; Beaux Arts Classical Photo by LM Drummond 2013

Distribution of Marble in Northwest Georgia

http://quarriesandbeyond.org/states/ga/images/ga-prelim_rpt_ga_marbles_1907_map_mrbl_nw_ga_p34.jpg Northwest, Georgia – Map Showing the Distribution of Marble in Northwest Georgia (circa 1907), from A Preliminary Report on the Marbles of Georgia, Bulletin No. 1, by S. W. McCallie, Assistant State Geologist, Geological Survey of Georgia, 2nd ed., 1907, pp. 34.

Slide 60 Igneous or Sedimentary Rock Type Metamorphic Rock Type

Almost any rock subjected to high-grade (high heat and pressure) regional metamorphism Gneiss

Sandstone (Sedimentary) Quartzite Limestone (Sedimentary) Marble Shale (Sedimentary) Slate Basalt (Igneous) Greenstone

Slide 61 Forms of StoneNaturally occurring or human-made

Fieldstone — from riverbeds or fields Flagstone — thin slabs used for flooring,

paving (stones split on a bedding plane) Rubble — irregular quarried fragments,

unsquared Dimension stone — quarried and cut into

rectangles– Cut stone: large slabs– Ashlar: smaller, rectangular blocks

Fieldstone

Fieldstone house, Mackinac Island, MI, 1920s http://stoneplus.cst.cmich.edu/1,A,Straits-ToEdit.html

Slide 63 FlagstoneBluestone — a colored sandstone popular

for flagging

Bluestone: A dense, hard, fine-grained, commonly feldspathic sandstone or siltstone of medium to dark or bluish-gray color that splits readily along original bedding planes to form thin slabs. Bluestone is not a technical geologic term. It is considered a variety of flagstone, with its thin relatively smooth-surfaced slabs suitable for use as flagging. Bluestone image: http://outdoorstones.blogspot.com/2012/09/how-do-you-cut-bluestone.html

Slide 64 Coursed = continuous horizontal lines

Uncoursed = discontinuous; no horizontal lines

Rubble (unsquared)

Ashlar (squared)

Slide 66 Courses and Wythes

Pronounced “with” or “withe” or “wythe”

Slide 67 Load-bearing Veneer

Weight of upper floors supported by walls of lower floors

Interior spaces smaller on lower floors

Arches, vaults, domes opened up space, reduced weight

Limited height due to volume and mass necessary to support the building

Skeletal framing system supports building– Wood– Metal (steel)– Reinforced concrete

Masonry veneer Taller buildings possible By early 1900s, most

stone and brick buildings in the U.S. were veneer

Load bearing masonry construction was the most widely used form of construction for large buildings from the 1700s to the mid-1900s. It is very rarely used today for large buildings, but smaller residential-scale structures are being built. It essentially consists of thick, heavy masonry walls of brick or stone that support the entire structure, including the horizontal floor slabs, which could be made of reinforced concrete, wood, or steel members.

In contrast, most construction today is not load-bearing masonry but frame structures of light but strong materials, that support floor slabs and have very thin and light internal and external walls.

The key idea with this construction is that every wall acts as a load carrying element. In a load bearing structure, you cannot easily punch holes in a wall to connect two rooms - you would damage the structure if you did so. The immense weight of the walls actually helps to hold the building together and stabilize it against external forces such as wind and earthquake.

Load bearing MasonryNote to the class: This is just some additional info on load

bearing masonry, which explains it a little more than I covered in class. This slide was not in Wednesday’s ppt presentation.

http://www.understandconstruction.com/load-bearing-masonry-construction.html

Slide 69 In traditional loadbearing masonry structures, the floor slabs were made of horizontal wood beams, joists, and planks. A joist is a smaller wood beam that rests on two larger beams.

The buildings were covered with sloping wood roofs, that could be finished with clay tile, wood or stone shingles, or metal plating such as thin sheets of copper. Other such buildings had flat terraces, that were built by pouring a concrete layer over a wood floor, and then finishing with some form of tile or stone to provide a strong, waterproof finish.

Every wall had a simple continuous strip foundation below it.


Slide 70 Load bearing masonry construction is not used today for a number of reasons:

It does not perform very well in earthquakes. Most deaths in earthquakes around the world have occurred in load bearing masonry buildings. Earthquakes love heavy buildings, because that is where they can wreak the greatest havoc.

It is extremely labor-intensive. This also makes for very slow construction speed in comparison with modern methods that are much more mechanized.

It is extremely material-intensive. These buildings consume a lot of bricks or stones, and are very heavy. This means that they are not green, as all this material has to be trucked around from where it is produced to the site.

OK, Drummond speaking here now. I disagree with the last statement, because if local stone is used or if the bricks are manufactured on site, then the building is more “green”, that is, environmentally friendly.


Monadnock Building; Chicago; unreinforced brick; 16 stories; 1891, Burnham & Root

18”

6 ft.

Slide 72 Expensive ashlar face (veneer) over inexpensive brick or rubble wall

(wall section diagrams)

https://environment7.uwe.ac.uk/resources/constructionsample/Conweb/walls/ashlar1abc.jpg In some forms of construction the facing stone is tied back to the brickwork/rubble with iron ties. These were quick to rust and could soon result in bulges appearing in the facework. The backing material would largely depend on the locality. In Bath and Bristol for example, there are several limestone quarries with cheap rubble stone available. In London, near to clay beds, brickwork was much cheaper.

Slide 73

Dressed stone over poured concrete

Concrete block over steel I-beam

More veneer examples

Modern

ties

Stainless steel tie in stone work: https://environment7.uwe.ac.uk/resources/constructionsample/Conweb/walls/sta4.jpg Tie diagram: https://environment7.uwe.ac.uk/resources/constructionsample/Conweb/walls/ashlar1abd.jpg

Slide 75

Stone over concrete masonry

units (CMUs)

Slide 76 Thin stone veneer over wood framing

What is the error in the labelling?

The framing should be in good shape for a masonry structure with studs spaced 16ʺ o.c. and rigid sheathing of gypsum wall board, plywood, OSB, concrete board or fiber board. OSB=oriented strand board

Thin stone veneer over wood framing

The framing should be in good shape for a masonry structure with studs spaced 16ʺ o.c. and rigid sheathing of gypsum wall board, plywood, OSB, concrete board or fiber board. OSB=oriented strand board

Slide 78 Stone Finishes

Crandalled

Rock faced

Broached

Tooth chiseled

Drove

Point chiseled

Building stones are often faced an inch or so from their edges. This dressed strip is known as the margin, or draft line, to distinguish it from the rock-faced. Top image with hand is a tooled finish in progress: http://www.nps.gov/hps/tps/briefs/brief42.htm Rock faced, split faced, pitch faced; image from underground Atlanta, Block Building, 1882 Tooth chiseled with margins: http://www.kopelovcutstone.com/carving_and_finishes.htm Point chiseled and margined: http://www.kopelovcutstone.com/carving_and_finishes.htm Hand broached and margined: http://www.kopelovcutstone.com/carving_and_finishes.htm Drove work: http://www.kopelovcutstone.com/carving_and_finishes.htm Crandalled and margined finish: http://www.kopelovcutstone.com/carving_and_finishes.htm

More Stone Finishes

Bushhammer

Rusticated

Bush hammered Wire sawn

Vermiculated

Top image: https://environment7.uwe.ac.uk/resources/constructionsample/Conweb/walls/sta2.jpg Bush hammer tool: http://stonesavvy.blogspot.com/2012/04/counter-top-stone-surface-series_25.html Bush hammered bluestone: http://yyzxm1984.stonecontact.com/member-product/BlueStone-Tiles-Slabs/Bush-Hammered-Blue-Stone-Tiles_148912.htm Rusticated: Sunken or beveled. Surface of the stone projects beyond the wall face; the back of the rustication, which may be a V-groove (as in this image from https://environment7.uwe.ac.uk/resources/constructionsample/Conweb/walls/stone_fin2.jpg) or straight sinking, represents the wall line. Rusticated may or may not have a rough face. Wire sawn: http://www.kopelovcutstone.com/carving_and_finishes.htm

Slide 80 Washington Hall,


Point, NY; gneiss

Washington Hall,


Point, NY; gneiss

Rock-faced, random ashlar

Slide 82 Modes of Deterioration

Solution Weathering Acid Rain Salt Weathering Dry Deposition Freeze-Thaw Cycle Hygric Swelling Thermal Effects Biological Effects

Natural stone is one of our oldest building materials, and is often regarded as a symbol of permanence. However, it is not absolutely durable and exposure to the weather over many thousands of years brings about eventual disintegration. The speed with which disintegration occurs varies according to stone type and environmental conditions, and it must be remembered that cutting and placing a stone in a building does not immunize it from natural weathering processes. However, it has become apparent over the last century that in polluted environments stone decay rates have greatly accelerated, so that the natural lifespan of stone can be drastically reduced from thousands to in some cases only tens of years in urban environments. Finally, remember that stone is not immutable. Human actions can speed up decay, but even without pollution-induced damage, exterior stonework is still subject to natural weathering processes and sometimes you have to accept that it has a finite service life. From: http://www.qub.ac.uk/geomaterials/w

eathering/usd.html

Slide 83 Solution Weathering

Occurs when soluble chemicals in stones dissolve in rainwater and get washed off and re-deposited elsewhere

Occurs naturally when rain falls– Rainwater is a weak carbonic acid formed by

the reaction of CO2 with atmospheric moisture– Carbonic acid can dissolve calcium carbonate

(primary component of limestones and marbles)

In polluted environment, rainfall acidity is increased & solutional activity intensifies

Slide 84 Solution Weathering, cont.

Marble headstone with lead lettering, 130 years old. Rainwater (carbonic acid) washes unevenly over the surface, causing pitting and wave-like deterioration patterns in the marble. The lead letters, originally even with the stone surface, now are “raised”, indicating how much stone surface has been lost.

Acid Rain

Mostly sulfur dioxides and nitrous oxides

Creates gypsum (hydrated calcium sulfate) on building surfaces

Loss of material—gets washed off and re-deposited somewhere else

The burning of coal, oil, and gasoline releases carbon dioxide, nitrogen, and sulfur into the atmosphere, which react with rainwater to form much stronger carbonic, nitric, and sulfuric acids that damage the environment ( acid rain). Gypsum—a soft, white sedimentary rock, hydrated calcium sulfate. Image is of Lincoln Castle carved figure in Lincolnshire, England

Slide 86 Acid Rain & Solution Weathering Processes

1. Rainwater - naturally composed of carbonic acid formed by Rx of CO2 with atmospheric moisture

2. Calcium carbonate is soluble in carbonic acid

3. Sulfur oxides in atmospheric pollution + water in the air form sulfuric acid. When it “rains” on stone containing CaCO3, it forms gypsum

The stone types that are most obviously prone to damage by acid rain are limestones and marbles made up primarily of calcium carbonate. This is because two complementary weathering processes can act them upon. The first of these is solution weathering. Solution loss is not unique to polluted environments and is also accomplished by natural rainwater. This is because rainwater is, as shown in Equation 1, a weak carbonic acid formed by the reaction of carbon dioxide with atmospheric moisture. Calcium carbonate is soluble in carbonic acid and reacts as shown in Equation 2. In polluted environments, rainfall acidity is increased and solutional activity intensified. This is particularly the case when oxides of sulphur are present in the atmosphere and a weak sulphuric acid is formed (Equation 3). If this falls on stone containing calcium carbonate it reacts with it to produce the salt known as calcium sulphate, or gypsum. Typically most of the gypsum is removed in solution as rainfall runs off the building, but if some of the rainfall soaks into the stone or is held

on the surface and subsequently evaporates, calcium sulphate can crystallize and contribute to the physical disintegration of stone by a process known as salt weathering. Although gypsum is the most common salt produced by acid deposition it is by no means the only one.

Slide 87 Salt Weathering Every salt has its own relative

humidity equilibrium point. Depending on the surrounding RH, the solution of salt can give up its water, forming salt crystals, which can split rock.

Marine environments De-icing salts Salt contained in Portland

cement—alkalis can migrate into the surrounding stone

Salt weathering is probably the most important agent of stone decay in cities. This is because salt crystallization and associated damage is possible every time a salt-contaminated stone is wetted and dries out. There are several mechanisms by which salt damages stone. When stones are wetted by rain or condensation salts are dissolved and washed into pore spaces. When drying begins, evaporation causes crystals to grow and press against surrounding grains. As long as the salt solution at crystal tips remains saturated they will continue to grow against the confining pressure of the surrounding stone. Repeated wetting and drying and resultant expansion and contraction can eventually lead to physical breakdown.

Dry Deposition Occurs on carbonate rocks (e.g.,

limestone, marble) constantly Fly ash and sulfur dioxide in the air

captured by the moisture that is always present in the stone formation of a crust

Occurs more often in winter– More particulates in the air– Greater temperature differential

more condensation, so the wet stone captures more particulates

Settling, impactions, adsorption—attracting and holding particles on its surface NPS monitors wet and dry sulfur and nitrogen depositions in the US, gathers weekly data on average atmospheric concentrations of sulfate, nitrate, ammonium, sulfur dioxide, and nitric acid. http://nature.nps.gov/air/monitoring/drymon.cfm Total sulfur deposition is much higher in the Eastern U.S. than in the Western states. With few exceptions, wet deposition is the major contributor to total deposition of sulfur. Total deposition of nitrogen is also higher in the Eastern U.S., however higher rates are also estimated for the Rocky Mountains. Again, most sites are dominated by wet deposition, however the majority of nitrogen deposition to Joshua Tree NP and Death Valley NP in southern California occurs as dry deposition. Images from pubs.usgs.gov/gip/acidrain/5.html Organization of American States building in Washington, DC: marble balustrade has gypsum crust, which causes stone to blacken, blister, and spall. Marble column from Merchants’ Exchange, Philadelphia. Loss of material where exposed to weather; formation of gypsum crust where protected from the weather.

Freeze-Thaw Cycle

More porous stones are more affected (e.g., limestone more susceptible than granite)

Water experiences 10% volume increase when it goes from liquid to solid (freezes)

Mechanical deterioration processes Mausoleum in Oakland cemetery, dressed surface of granite has spalled off.

Slide 90 Stonework should be laid on the quarry bed (grain running horizontally) because stone is stronger and more weather-resistant in that orientation.

Slide 91

Photo courtesy of Ben Sutton, 2014

Sandstone—deteriorated, then replaced

1767-1771 Town Hall (originally market), built of local Scrabo sandstone [Newtownards, County Down, Ireland) Image from: http://www.flickriver.com/photos/kilwirraarchitects/tags/conwaysquare/

Slide 93 Hygric Swelling Clay swells when it gets wet; differential strain

between wet and dry areas causes deformation, stress, cracking

Sedimentary rocks more susceptible: weaker mechanically, more porous, have layers, contain clay

Slide 94 Bio-deteriorationPhysical and chemical processes

Bacteria, algae, and fungi — cause mostly chemical effects; have a specialist identify these

Lichens — chemical and physical effects; can tear away surface of rock; hard to clean

Mosses — mostly physical effects; easier to remove than lichens

Higher Plants — can damage surface and retain moisture

Bacteria effectively digest minerals, and colonization by algae and fungi enhance the dissolution of the stone.

Algae growth on sandstone

Lichen growth on stone wall

Algal growth on sandstone two years after cleaning. Some algae live on the surface of limestone, while other types can live beneath the surface. Algae and fungi can form film over the stone, which does not allow it to breathe. In particular, any moisture that does penetrate will dry out more slowly, the stone will stay wetter for longer and any dissolved salts could penetrate more deeply. Lichen growth on stone wall image at right: http://www.flickr.com/photos/smilla4/8007830976/

Slide 96 Plant-covered brick building

Vancouver, Canada, July 2002. http://www.pbase.com/jb0707/image/2958246/original

Thermal Effects Coefficient of linear thermal expansion = rate at

which mineral expands with increasing temperature

Stone temperature can vary between 30%-50% higher than air temperature

Darker stones absorb more heat and give it up more readily

Daily and seasonal heating cause stress and micro-fractures in and along mineral grains, eventually producing flaking

Mable is particularly susceptive to thermal effects

Creep or drift — building expands during day but does not fully contract at night

Step cracking following mortar joints near the building corners and where the wall movement was resisted by first story intersecting brick walls abutting at right angles the middle section of the long brick wall. Thermal expansion effect on brick: http://inspectapedia.com/structure/JCCbrickfailure16DJFes.jpg

Slide 98 Before cleaning or repairing stone: Know what the stone is, and its source Understand the nature of the stone:

grain, chemical composition, crystal structure, water solubility

Understand the structure: number of wythes, type of fasteners or dowels

Analyze the mortar (composition, color, texture, type of joint)

Know the chemical composition of pollution/salts

Slide 99 Cleaning Masonry Water wash – fine spray directly onto element

(removes gypsum crust) Chemical cleaners – acidic, alkaline – use

extreme care; watch dwell time; rinse thoroughly. Environmental hazard, containment is essential.

Hot water, steam – degreasing Particulate cleaning – more easily localized; can

perform partial cleaning; can be used on different stones in juxtaposition; containment problems; requires trained operators

Lasers – can clean extremely fragile surfaces; can only clean light surface with dark soiling; primary risk is yellowing

Cleaning Dry Deposition — Reconversion of gypsum films into calcite on the surfaces of

monuments & statues Gypsum on marble forms crust that preserves

underlying design details Gypsum crust itself is fragile Washing gypsum off stone surface causes loss

of historic material, esp. carving relief details Inversion of marble sulfation — chemically

return gypsum to calcite (CaCO3) by spraying K2CO3 (potassium carbonate) on stone– Consolidates layers of stone, preserving design details– Calcite is five times harder than gypsum– Calcite is 29,000 times less soluble in water than

gypsum

Inversion of marble sulfation-reconversion of gypsum films into calcite on the surfaces of monuments and statues The work combines the authors' observation that the details of marble statues that have already been lost from the calcite surface are preserved in the gypsum layer, with their research on the mechanism of marble sulfation, to lead to a consolidation of the gypsum, transforming it back to calcium carbonate (calcite) using carbonate ions in solution. The reproduction of the surface detail and the improvement of the mechanical properties were very satisfactory. https://www.iiconservation.org/node/604

Slide 101

http://www.ysma.gr/en/conservation-degradation-phenomena Marble sulfation

Traditional Modern ParticulateSandblasting Cleaning

Larger particulates, diameter = one mm

Delivered at hundreds to thousands psi (pounds per square inch)

Particulate used – True sand (quartz)

Smaller particulates, diameter = tens of microns

Delivered at tens of psi Particulates used:

– Walnut shells– Sodium bicarbonate (Armex)– Dry ice– Calcite or dolomite particles– Façade grommage

Glass beads Aluminum oxide

Modern brick will lack the porous “salmon” center known to be the remaining condition of an historic brick fired in a down-draft kiln. Modern bricks are thoroughly fired in a tunnel kiln which results in more uniform densification throughout. But even modern brick will become “pitted” by the sharp sand action of a sandblaster.

Slide 103 Power Washing / Sandblasting

Power washing image: http://www.multipino.com/offer158340.html Sandblasting image: http://www.heritage-house.org/page.php?pageid=60

Slide 104

Sandblasting Historic Brick

Sandblasted brick (to clean it) at Charles Sturt University, Albury, Australia: http://www.flickr.com/photos/heritagefutures/4961535999/in/photostream Sandblasted historic brick to create a mural in Quebec, delivered at 2000 ppsi, onto tenants’ stores, several hundred years old: http://www.william-mitchell.com/sandblasting.htm

Repairs to Stonework Re-tool mortar joint Re-dress surface of the stone Re-attach using adhesives and pins, dowels,

or staples Patching (Dutchman or composite) Use consolidants (alkaoxysilane monomers) Remove and replace stone Dismantle and rebuild wall Remove and replace corroded metal elements Do all work in accordance with the Secretary’s

standards

Slide 106

Washington Park,

Charleston, SC

Inappropriate & Appropriate

Repairs

Marble, in contact with inappropriate Portland cement, over time and with weathering, began the process of granular disintegration, a “sugaring” of the marble.

Slide 107 Preservation Briefs

#1: Assessing Cleaning and Water-Repellent Treatments for Historic Masonry Buildings

#2: Repointing Mortar Joints in Historic Masonry Buildings

#6: Dangers of Abrasive Cleaning to Historic Buildings

#38: Removing Graffiti from Historic Masonry

Brick Face Names

A stretcher is usually the equivalent of two headers plus one mortar joint

Slide 109

A queen closer is shorter than a header.

King & Queen Closers

Slide 110 Queen Closers

used in the header course of the English bond

pattern

Rebekah Scott Hall, 1905, Morgan & Dillon, Agnes Scott College, Decatur, GA

King Closers used in the

header courses of the English bond

pattern


Slide 112 Brick Construction

Structural (load-bearing) brick — more than one wythe thick; usually at least three. The brick is holding up the building.

Brick veneer (curtain-wall) — over skeletal framing of wood, steel, or concrete. The building is holding up the brick.

Slide 113 English Bond — used in North America through mid-1700s

A very strong bond pattern; often used on rear & side facades, for bridges; considered less

decorative

http://buildipedia.com/knowledgebase/division-04-masonry/04-20-00-unit-masonry/04-21-00-clay-unit-masonry/04-21-13-brick-masonry/04-21-13-brick-masonry

Slide 115

Bridge ca. 1765 in England http://www.uwe.port.ac.uk/walls/bridge.jpg

Slide 116

A queen closer is shorter than a header.

King & Queen Closers

Queen Closers

used in the header course of the English bond

pattern


Slide 118

King Closers used in the

header courses of the English bond

pattern


Slide 119 Flemish Bond — Popular from 1720s – 1800

Not as strong as English bond, but considered more decorative; used on front facades


Slide 121 Note folds in brick—from hand-packing of

the wood molds

1780s Flemish bond brick wall; lime-based mortar. Note folds in brick—from hand-packing of the wood molds. http://www.uwe.port.ac.uk/walls/weyflem3.jpg

Slide 122 American Bond, aka Common Bond

Mid-19th – early 20th centuries

This one is a King closer.

American bond or Common bond

Header course

Stretcher course

You must always designate the number of stretcher courses between the header courses when referring to

American bond. Below is “five course American bond”. I f you just say “American bond”, that is incorrect. The

number of stretcher courses can vary. I have seen from 3-8 stretcher courses between the two header courses

This one is a King closer.

Five Course American bond or Five course Common bond

Header course

Stretcher course

Slide 124

Five course American or Five course Common Bond


Slide 125

Bulloch Hall, 1840, Willis Ball, Roswell, GA. South façade. Varies from 4-7 course American bond brick pattern.

Running Bond — 1920s - present

Slide 127


Slide 128

Urban Life Plaza; J. H. Finch of Finch, Alexander, Barnes, Rothschild and Paschal (FABRAP), architects, Atlanta, GA; J. A. Jones Construction Co., builder; 1974; Georgia State University, Atlanta, GA

Running (Stretcher) Bond

Most often used today as a single-layer veneer over a structural backup wall (wood frame, metal frame, concrete block, poured concrete) – It is anchored into the structural wall with stainless steel ties

(or anchors)– Specialized anchoring required in high wind or seismic areas

Was used historically (pre-20th century) as the outer wythe of a load-bearing masonry structure, but was anchored into the rest of the wall in a variety of ways– Using iron ties (which rusted over time)– Using a variety of brick formations

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