In this video we will discuss a traditional Louisiana construction method
called Bousillage. Bousillage is a Louisiana French term for walls made of
mud. The origins of the word comes from Bous which means mud. Louisiana’s
bousillage techniques appears to be a blend of French and Native American
traditions. Both cultures employed similar mud walled building techniques
and traditions tell us that the early French colonists and Native Americans
worked together. Commonly in the 18th and 19th centuries bousillage was
used for buildings that ranged from small cottages and outbuildings to the
finest of mansions.
The material that makes bousillage unique is the Spanish Moss. Spanish
Moss is a unique feature to the southern landscape. This flowering plant
can be found hanging in the branches of any variety of trees in the more
humid regions of the tropic and subtropical latitudes. In North America
Spanish Moss ranges from Texas to Florida and as far north as Virginia
along the eastern seaboard. This plant is not parasitic but actually a
true epiphyte and gets its sustenance from the atmosphere and it not rooted
into the tree in any way.
Traditionally the moss is gathered in the spring time when it is most
abundant. Most moss is gathered directly from the trees by use of a long
bamboo or cane reed pole, any moss found on the ground is also gathered.
Once any captured sticks or leaves are removed from the moss it is bagged
for processing. Keep in mind that it takes a lot of moss for the making of
bousillage. Traditionally Spanish Moss was prevalent in southern and
central Louisiana.
It is this reason that the moss was such a good building material. As late
as the 1940’s gathering and processing Spanish moss was a major industry in
the state of Louisiana. During the 20th century Spanish moss was used for
automobile and furniture upholstery. Unfortunately, due to the heavy use
of chemical exfoliates to harvest cotton; Spanish moss is a rare find in
central Louisiana today.
Once the moss has been gathered it must be processed or retted. The
processing of the moss is done by digging a shallow ditch usually on the
site where the building will take place. The Spanish Moss is then stretched
out into the ditch and buried over. This remains buried for four to five
months, the time out of the sunlight kills the moss and reduces it to thin
but very strong black fiber. This black fiber is mixed directly into the mud
for bousillage. In some traditions the moss is boiled after being brought
out of the ground this helps to remove any remaining greenish grey covering
of the living plant.
This is the green moss that we picked this morning. This is the way it looks
like before it was retted. And this is how it looks like after it has been
buried for four to five months. It has cured now and this is the type we use
when we are making bousillage.
Now that the moss is prepared the soil must be chosen and gathered. For
bousillage a silt soil is used. Traditionally, the soil is gathered on the
high ground near the levees, often at the building site, this helps to avoid
the heavy clay deposits that can be found on the river backs. After the soil
is gathered it is commonly sifted to remove any large organic matter or
foreign objects such as sticks, roots or rocks.
Now lets look at methods for repairing historic bousillage.
Here we are inside the Cook's Cabin at the Oakland Plantation looking at the
original historic bousillage walls. Unfortunately due to age some areas of
this bousillage have failed. It has become very pliable and very frail. And
its had to be removed in areas such as this. As we can see here some of the
original bousillage was made with straw. Probably from here on Oakland
Plantation. The repair mix that we are putting back will use the traditional
Spanish moss. Once all these areas, the large and the small, are patched we
will actually lime wash the wall like it was originally intended. We can see 58 00:04:02,000 --> 00:03:07,000 some evidence of the original lime wash still intact. This is also one of
the important reasons why we have added the fiberglass reinforcement fiber.
That way we can delineate between our repair work and the original bousillage.
Hello I am Moss Rudley with the National Park Service Historic Preservation
Training Center. We are mixing bousillage here today at the Cook's Cabin at
Oakland Plantation. Bousillage is a mixture of loamy soil gathered along the river
banks here, a small amount of lime, cured Spanish moss and in this case we are
using concrete reinforcement fibers to clearly delineate between the historic
material and the replacement material that we will be putting into the wall today.
It will then be mixed with water and formed into loaves, placed over the rabots
and or in the small cracks that have formed in the historic material.
Here in this corner of the Cook's Cabin we can see much of the original bousillage
has failed. However this is fortunate for us that we can see how the original
wall was constructed and most importantly what we can look at are these slats.
These are referred to as batons or rabots. These are local hand-hewn cypress that
are then notched into the wall. This is what will build up the wall using our
bousillage. We will actually form what is called a mud cat and the mud gets laid
over it and thats how we build the bousillage wall. Before we begin with any
repair work we must first wet down the wall with a mist of water. This will soften
the historic material and help the new material bind to it.
Once the bousillage has been mixed with water and the wall has been moistened the
repair material is pushed into the cracks and voids of the historic wall. This
process is very similar to the repointing of brick or stone masonry and uses the
same trowels.
In this section of the wall most of the original bousillage has failed, to replace
this we must first make loafs or mud cats of bousillage to lay over the Cyprus
rabots. As the wall is built up the loafs are smoothed down to bind with the material
below. Some pointing may need to be done to connect the newly laid section with the
historic wall.
Once the repair work is completed the wall will need to dry out before the finish
coats of lime wash are applied. The time it takes to dry will depend on the weather
and airflow to the wall. Typically the wall will take a few days to dry. The original
wall was constructed using the same method of laying the mud loafs over the rabots.
Now that the bousillage has cured we can apply our finish coat of lime wash. First
we wet down the wall with a mist of water. This will soften the bousillage and help
the lime wash bind to it. Natural lime wash is the traditional method for finishing
the interior and exterior of bousillage walls. The lime wash seals the wall but still
and application please see the NCPTT website keyword limewash.
Bousillage buildings in Louisiana are being lost every day due to neglect,
demolition, and ignorance for the material. It is important that we repair, rebuild
and protect this vanishing cultural heritage.