As the most viewable
buildings still standing, the 21 California Missions are California history. They
serve as the main inspiration for custom home architecture in Southern
California, and provide every 4th grader in the State with a unique
education. Some would argue that the
Missions in California represent a unique architectural style all their
own. Plaster products were widely used
in the Missions, and provide the stucco industry with its most relevant
historical reference point.
When people ask “Why is stucco
so common in the Southwest?” my answer is “The Missions.” Their building methods set a precedent that
continues to today, rooted in Spanish, Moorish, and Mexican traditions. From the first Mission begun in San Diego in
1769 to the final one begun in 1823 north of San Francisco, the network of
Spanish Missions did more to create the stucco industry than any other single
factor.
The Missions all started very
humbly, as these were frontier outposts.
They worked with what was available, adobe, ladrillo bricks, and stone. “The first temporary quarters, hastily built,
were little better than brush huts with grass-thatched roofs… The second
structure at most of the missions was of adobe…. As soon, however, as a mission
was strong and prosperous, the pride of the padre usually extended to an
ambition to build a church in more lasting material, hence stone or burned
brick were employed.”[1]
The Church at Mission Santa
Barbara, made of stone
As through the course of
human history, once the Missions became prosperous, they were plastered. “All mission churches had exterior plaster of
lime-and-sand stucco, following the Roman formula of three parts clean washed
sand to one part burned lime, slaked with water.”[2] It seems hard to believe, but the Mission construction
projects drew from Roman records of building techniques written 17 centuries
earlier, notably Vitruvius’s De
architectura, as evidenced by the books found in several Mission
libraries. So perhaps we have Vitruvius
to thank for today’s stucco industry.
Mission Walls & Ceilings
Together with the clay roof
tiles, the plaster served a vital function, protecting the underlying adobe
blocks, ladrillo bricks, and stone units in the walls from moisture. “When roofed, plastered, and protected from
groundwater, adobe walls are enormously durable and provide effective
insulation, although their soft surface does not lend itself to decorative
relief.”[3] A lime-based whitewash served as the final
wall surface as additional protection from the weather and also to provide an
attractive finish.
Mission compounds were mixes
of adobe blocks with limewash, structures of adobe and kiln-fired ladrillo
bricks, and stone. The prosperity of the
Mission at the time of construction and the function of the building determined
the materials. “For important buildings
such as the church and the convento, the final plaster would be made of lime,
producing a hard and durable finish.”[4] Ladrillos provided improved weather
resistance and sharper lines that were not possible with adobe, and are widely
used at Mission San Luis Rey (Oceanside), Mission San Antonio (Monterey County)
and Mission San Diego. Prominent stone
churches were built at Mission Santa Barbara, San Gabriel, and the now ruined
San Juan Capistrano. Nothing made a
prouder padre than building a stone church clad in white plaster.
The church at
Mission San Luis Rey, built with adobe and kiln-fired clay ladrillo bricks
Interior Wall Decoration
While exterior walls were
left simple and bare, interior walls were decorated extensively. Where Mission jobsites couldn’t use expensive
wood and stone features, they often painted them on the walls. “Dado” wainscots were common, as were painted
cornices at the tops of the walls. “True
fresco painting was rare in Alta
California, identified only recently at the Royal Presidio Chapel in
Monterey. This technique is executed on
wet plaster, allowing the paint to bond with the wall surface and resulting in
a more durable finish.”[5]
This wall painting came from
Mission San Fernando Rey
Visitors to today’s Mission
museums might be surprised to learn of the colorful decorations used on the
Mission interiors, because most have been covered up. “…when the Catholic and Hispanic heritage of
the missions was widely unpopular, some mission interiors were redecorated
according to British Victorian taste or whitewashed to modernize and dim their
Hispanic origins.”[6] Many painted decorations were whitewashed
over, covered in wood paneling, or damaged by years of neglect. Many of these decorations only survive today
because of a New Deal-era survey of American art called the Index of American Design. Now housed at the National Gallery of Art in
Washington, D.C., the Index contains the full spectrum of American art up to
the 1930s, and included many California Mission wall decorations that would not
have survived to this day, if it weren’t for the Index. See http://www.nga.gov/collection/iad/index.shtm
to see some for yourself, listed under Folk Arts of the Spanish Southwest. Mission San Miguel, just off the 101 freeway
near Paso Robles, is the only surviving completely original interior.
The Hispanic builders and
Native American workers were both experienced with paint materials. “Red was made from hematite (red ochre) and
cinnabar, white from diatomaceous earth (chalklike fossil rock), and black from
charcoal, burned graphite, and asphaltum.
To these sources the Spanish added pigments imported from Mexico… and
linseed oil, used as a binder.”[7] One Chumash Indian artist was said to have
used “meat of the red tuna, egg whites, and pitch to the pigments. He also used urine, which he collected in
clay pots, as a mordant for the paint.”[8] Sometimes the old way is the best, as with lime
plasters; other times the old way is best left buried, as with urine paints.
Restoration of California Missions
As the Missions faded from
the public interest, they were neglected.
The fairly simple maintenance required to preserve adobe and stone buildings
was not done, and in extreme cases, walls were dissolved back into the mud from
which they were made. Earthquakes
accelerated the pace of deterioration of many of the mission buildings.
Concerned citizens groups got
organized to save and restore the Missions, and thankfully many are now
maintained and well financed. The
restoration work done on the missions has shown what works with these walls and
what does not. Portland cement repairs do not work.
Well-intentioned repair
efforts used Portland cement in the 1940s, 1950s, and 1960s on walls that had
lasted almost 200 years by then.
Portland cement was stronger than the original materials, cheap, and
readily available. So it was reasonable
to believe that cement repair products would only strengthen the
structures. But, “when cement was
applied to adobe walls, often over chicken wire, its hard, water-repellent
surface proved so impermeable that when moisture did occur in the walls it
remained trapped behind the cement veneer, slowly eroding the adobe wall from
within… In other cases, a cement mortar was added to ladrillo constructions;
over time, the stronger mortar pulled away the surface of the tiles.”[9] The lime mortars and plasters, on the other
hand, that had ably protected the walls for decades, when properly maintained,
“are porous and “breathe”, allowing modest dampness to evaporate. Traditional lime- or earth-based renders
(exterior plaster) and finishes protected adobe bricks from direct contact with
the weather, providing an easily replaceable sacrificial layer.”[10]
“Modern conservation practice
recommends that cement coverings, including renders, plasters, and “aprons”
(surface coverings placed along the lower portions of walls), be replaced with
renders and mortars similar to the original material, allowing the walls to
breathe… Now mission ladrillo arcades are remortared and restuccoed using soft
lime mortars.” [11] Lime is the right material for these
structures, because of its breathability, durability, and ease of
maintenance. Plus, the hard feel of
cured limestone hides an inner softness that gently coats and supports masonry
units without breaking them (like Portland cement products will).
Restoration at Mission San
Juan Capistrano, for example, strives to reproduce as closely as possible the
original construction of the walls. “To
reinstate the historic character of this area, removal of all inappropriate
past repairs, mainly the use of cement, is a key element to the project. Work on the masonry columns includes the
removal of hard cement mortar at the joints between the bricks and repointing
with a softer, more compatible lime mortar.”[12]
Restoration work at Mission
San Juan Capistrano using lime mortars to repoint bricks
Products Available for Mission
Restoration Projects
Thanks
to their softness, breathability, and protective qualities, lime mortars, lime
plasters, and lime washes are ideally suited to restoration of Missions and
other buildings of similar construction.
There are several products that have established themselves in this
niche. Headquartered in Orange,
California, Vero imports Italian seasoned-slaked lime mortars, plasters, and
lime washes, produced in much the same way as those used by Vitruvius in
Ancient Rome. Malta Grezza/Fine are ready-to-use
lime mortars, and are made more weather-resistant through the addition of
Cocciopesto (brick dust). This technique
is consistent with that used for reservoirs and fountains in the California
Missions, which “were often rendered with water-resistant coccio pesto,
hydraulic lime stucco made pink by the admixture of ground terracotta tiles,
another Vitruvian formula. Coccio pesto
was also used on architectural elements, such as the ladrillo colonnade columns at Mission Santa Ines.”[13]
Malta
Grezza & Malta Fine produce this characteristic pink tone when Cocciopesto
is used to provide added water-resistance and faster set.
Lime washes (such as VeroEpoca 800) are an ideal finish coat over a lime mortar, as they beautify, can
add color, and cross-link with the lime mortar to provide a water-shedding
topcoat. “[Limewash] gives a smooth
coating which, after an initial wetting, encourages an easy run-off of rainwater. At the same time the nature of this surface
allows good, all-over evaporation which helps the wall to dry out. Limewash is unaffected by the ultra-violet
rays in sunlight which destroy synthetic paints.”[14]
Vero lime plasters can also
be used as topcoats over the lime mortars, when smooth textures and a more
substantial color coat is desired. “Lime
plaster is extremely strong stuff that has withstood hundreds of years of
weather. Moreover, because it is pliant
(somewhat flexible), lime plaster is not likely to crack very much as a
building shifts or walls expand and contract in response to natural temperature
fluctuations or as moisture levels rise and fall… In addition, lime plaster and
earthen materials expand and contract similarly. Consequently, when lime plaster is applied on
an earthen wall or an earthen plaster, it is less likely to crack or peel off a
wall.”[15]
Other manufacturers also
carry lime mortars, including the bagged Natural Hydraulic Lime products
imported from France by Transmineral USA out of Petaluma, California. Their Ecomortar product is preblended with
properly graded sand and ready to use.
Lime finishes are available from many companies in California and
elsewhere in the U.S.
Conclusion
Next time you’re near a
Mission, pay it a visit. If you’re in
the plastering business, you’ll pay extra attention to how the walls were
built, and you should thank the Franciscan Padres for bringing plaster to
California and planting the seeds for the architecture, materials, and techniques
used today. The same materials used in
building the Missions are available today, and should be used exclusively in
preserving these and other historic buildings.
[1] E.
Engenhoff, Fabricas (Sacramento:
California Division of Natural Resources, Division of Mines, 1952), 181, as
observed by Eugene Duflot de Mofras during his visit in 1840-42.
[2] E.
Kimbro & J. Costello, The California
Missions, The Getty Conservation Institute, 2009. p. 94
[3] Ibid.,
p. 96
[4] Ibid.,
p. 97
[5] Ibid.,
p. 135
[6] Ibid.,
p. 146
[7] Ibid.,
p. 134
[8] Ibid.,
p. 147
[9] Ibid.,
p. 156
[10] Ibid.,
p. 156
[11] Ibid.,
p. 156
[12] “South
Wing Conservation”, http://www.missionsjc.com/preservation/projects-southwing.php,
July 10, 2012.
[13] E.
Kimbro & J. Costello, The California
Missions, The Getty Conservation Institute, 2009. Chapter 4 note 7
[14] Holmes
& Wingate, Building with Lime, ITDG Publishing 2002, p. 49
[15]
Guelberth & Chrias, The Natural Plaster Book, New Society
Publishers, 2003, p.165
