While
this issue is not at the centre of the unity debate, we in
Ontario should realize that Canadians in the rest of this
country think we're a little nuts because of our fixation
with brick houses. Our theory is that people in Ontario were
raised on stories like the "Three Little Pigs". We want a
house that nobody can huff and puff and blow down. There's
Brick and Then There's Brick
What
most people in Ontario don't realize is that there are
two very different types of brick houses, brick veneer
and solid masonry.
Solid
Masonry
Solid
masonry construction is also called ‘Solid Brick', ‘Double
Brick', and sometimes ‘Brick and Block'. In its most common
form, a solid masonry wall consists of an outer layer of
brick and an inner layer of brick (a layer of brick is
called a ‘wythe' in masonry circles).
The
reason why solid masonry is a more accurate description than
solid brick or double brick is because the inner wythe may
not be brick. Because the inner wythe will never be seen,
concrete or cinder block is sometimes substituted for brick.
As
a brick wall increases in height, there is more and more
danger that the inner wythe will separate from the outer
wythe. To hold the two wythes together, header bricks are
installed, usually every six rows. From the outside, header
bricks look like regular bricks except they are shorter.
In reality, they are the same size as a normal brick, however
they are installed sideways so that the end of the brick
is visible from the exterior of the building. The header
bricks act as a bridge between the outer wythe and the inner
wythe and prevent the two from separating.
Therefore,
most solid masonry walls display header bricks in every 6th
row or course. Sometimes, every brick in the course is a
header brick, however there are a number of common patterns.
It is not unusual to see two long bricks followed by two
short ones then two long ones then two short ones. (The long
bricks, by the way, are called stretchers.)
Sometimes
bricks are installed over windows with their long face parallel
to the wall but the brick standing on its end. These are
called soldiers.
It
is possible to build a solid masonry wall using metal ties
to hold the two wythes of masonry together. When this is
done, no header bricks will be visible and the wall can easily
be mistaken for a brick veneer wall.
So
What's so Good About a Solid Masonry Wall?
There
is no question that the big bad wolf will find this wall
the hardest to blow down. Structurally, solid masonry walls
are very strong and can, if properly maintained, provide
hundreds of years of service.
What
is Brick Veneer?
If
solid masonry is so good, why is it that most brick houses
built in the last 30 years are brick veneer construction?
Firstly,
we have to understand the difference between brick veneer
and solid masonry. The biggest difference is that with solid
masonry, the brick is holding up the house. With brick veneer,
the house is holding up the brick!
When
we say brick veneer, we don't mean those little thin slices
that you glue on your kitchen wall. We mean an honest to
goodness brick. However, the wall is only one wythe thick.
Behind the brick veneer is a wood frame wall which is actually
holding up the house. The brick veneer is, in effect, siding!
Insulation
Brick
veneer became the norm when building codes began to require
insulation in the exterior walls. One of the best insulators
is air. Most good insulation does nothing but trap air;
that's why most insulations are light and fluffy. Brick
is not exactly light and fluffy. Therefore it's not really
a very good insulator. A brick veneer house then, is really
a wood frame house where the cavity between the studs in
the wall can be insulated.
The
walls are built, covered with sheathing and often insulated
before the brick is even installed. As the brick is being
installed, metal ties are nailed onto the wood frame wall.
It is important that they be nailed into the studs and not
just into the sheathing. The metal ties are then bent so
that they are horizontal where they become imbedded in the
mortar joints as the brick veneer wall is constructed. The
brick veneer is built on the outer edge of the foundation
wall so that a one inch air space remains between the brick
veneer and the sheathing.
How
Waterproof Is Brick?
The
short answer is "not very". With a wind driven rain, moisture
will pass right through a brick wall. The one inch air
space behind the brick allows this water to run down the
back surface of the brick. At the bottom of the wall cavity,
a plastic or metal flashing collects the water and allows
it to drain out through weep holes. You'll find weep holes
spaced at approximately 32" (every fourth brick) along
the top of foundation walls and above doors and windows.
Not
only do the weep holes let the water drain out of the wall,
but they also allow the wind to get behind the brick and
pressurize the one inch airspace between the back of the
brick and the sheathing. Believe it or not, this extra
air pressure reduces the amount of rain that gets forced
through the wall.
So
Which is Better?
Well
that depends on your criteria. Solid masonry walls are
certainly stronger, however brick veneer walls are plenty
strong and are certainly better insulated. In the big scheme
of things, the differences between the two types of construction
should not be important enough to affect a purchase decision.
In the interests of national unity, you shouldn't even
care whether the house has any brick.