Our homes might be made of brick and plaster, our cars of metal and
plastic, and our sheds and coops of lumber, but their surfaces – the
part we see – are usually paint. Those flashy colours, though, often
contain an alarming stew of ingredients – benzene, tricholoroethylene,
formaldehyde, and many others – all of which flake off over time but
never, of course, truly leave us. That’s not even counting the lead, now
long banned, but which lingers in soil for generations.
So when our chicken coop needed some brightening, we took the
old-fashioned route and whitewashed. Whitewashing was used on buildings
here in Ireland into the late 20th century, only recently replaced by
more dubious alternatives. Whitewash can consist of as little as two
short ingredients – lime and water – that can be mixed and prepared with
almost no energy in a few minutes. It is non-toxic enough that animals
can actually lick it off with few or no ill effects, but antiseptic
enough to discourage bacteria in the coop or dairy.
Lime refers not to the fruit or unrelated tree, but to a product made
from burning limestone in a kiln. Limestone is mainly coral and shells
of long-extinct sea creatures, squeezed over aeons into a solid mass of
calcium carbonate, or CaCO3. When burned it vents carbon dioxide (CO2),
leaving behind the volatile calcium oxide (CaO) or “quicklime.” When
combined with water – hydrated or “slaked” – it becomes calcium
hydroxide or Ca(OH)2, or simply called “lime.”
Humans have been creating lime this way for several thousand years,
putting it to many uses; as a mortar for building, as an early form of
cement, as an antiseptic ointment for animals or an anti-fungal coating
for trees. A bit of lime could help remove hair from hides, sterilise
water, bleach paper, deter slugs from a garden, or preserve eggs for
months. It could be worked into boggy and acid soils to increase the
fertility many times over. Also, it colours walls.
Its brilliant whiteness was valued here in Ireland, an island a
thousand miles from the Arctic Circle where the winters grow very dark
indeed. Cottages here were traditionally whitewashed in spring, as the
rainy season gave way to the slightly less-rainy season, and again as
part of the ritual leading up to Christmas.
The whitewash also showed too plainly when straw roofs needed to be
re-thatched. After a decade or so, moss and algae build up on a straw
roof, and when it rains the water runs off the roof and leaves green
streaks down the whitewash. When a family had such visible stains, they
were said to be “selling laces” – having money troubles, too poor to
re-thatch.
Some old houses here were made with cob (sand, clay and straw mixed
into something like cement) or wattle-and-daub (a mesh of flexible wood
with a clay plaster coating), and as both were susceptible to moisture,
the whitewash might have provided an early-warning system, showing where
the owner needed to watch for erosion.
After experimenting a bit, we settled on a rather simple recipe: 2
cups of water for every cup of lime, with a 1/4 cup of salt thrown in.
It was a particularly thick ratio and flaked off a bit when drying, so
next time we might try a thinner combination. Once mixed, the wash can
be applied with regular paintbrush strokes – or with my 9-year-old’s
more Jackson-Pollock-inspired approach. It looks thin and transparent at
first, but whitens as it dries. Wear gloves and goggles – lime is only a
mildly caustic alkalai, but work with it all day and you’ll get raw
hands.
We also tried mixing milk in as well, recommended by many old books,
but found the effect no different, so the extra expense of milk was not
justified. Milk powder, however, comes much more cheaply, and could hold
some promise. Farmers here sometimes added oils – linseed was most
popular – to make it more waterproof, or strengthened it with animal
hair or cereal husks.
To be sure, whitewash has disadvantages; it is water-soluble, for one
thing, so rain washes it away. This presents little problem when the
sides are under a slight overhang, like the sides of our coop or most
houses, but when it showers, our hen-boxes receive a gusher of water
from the roof, and we had to divert the water with a plastic awning or
the white coating wouldn’t have lasted long. Even in dry weather,
however, whitewash flakes off over time, and powders your clothes when
you rub against it. The good news is that it leaves no permanent stains.
It is also, almost inevitably, white – although in the west of
Ireland, I’m told, some farmers painted their houses pink by mixing
pig’s blood with the wash. The fact that lime was cheap and easy, while
coloured paints were expensive, probably accounts for the classic look
of Irish homes – clean white exteriors accented by brilliantly coloured
doors and windows.
Locals here seemed familiar with many vegetable dyes or fabrics –
elderberries for lavender; red cabbage or brambleberries for blue;
nettles for green; St. John’s Wort for magenta; and marigolds,
calendula, dock root and onion skins for yellow. Many of these colours
are also water-soluble and fade quickly – which modern people think of
as a disadvantage, although some valued the muted colours.
Some traditional peoples did create natural pigments, however, by
boiling various clays and minerals – yellow and red ochre, sienna,
umber, cinnabar and iron oxide for reds and browns, copper ore for green
paints, urine for yellow, lampblack or charcoal created blacks and
greys. Wherever you live, your plants and soil probably have their own
palette of colours, which you can use at least as well as the
Neanderthals who painted long-extinct animals on cave walls.
