When you can't support brick veneer on a masonry
foundation, code allows you to use steel angles bolted to the
framing — with strict limitationsby Christopher DeBlois,
Brick veneer poses few structural problems, as long as it can
support its own weight all the way down to the foundation, or
is supported by properly sized steel lintel angles at door and
window openings. But introduce more complicated conditions
— a bay window that projects from the main exterior wall,
say, or even something as common as a two-car garage door
— and brick veneer can start to look like more trouble
than it's worth.
As a case in point, how do you support the brick when a lower
one-story garage roof meets a two-story wall, with brick on the
common wall above the garage roof?
Several JLC readers have posed this question, having seen
examples where builders doubled up the roof trusses directly
below the brick, then laid the brick directly on the roof deck.
I don't recommend this approach, because rafters and trusses
carrying the weight of brick would typically not have adequate
strength or stiffness to meet most codes. Also, the roof
framing will move at a different rate than the wall framing
that the brick is anchored to, which could cause visible
cracking in the mortar joints.
Using Steel Angles
A better solution is to support the brick above the garage roof
with a steel shelf angle bolted to the stud wall at the
main-house wall (see illustration).
Supporting Brick Veneer With Steel
Supporting brick veneer on steel angles bolted to the framing
— rather than providing masonry bearing all the way to
the foundation — is approved by code, but it's important
to get the details right to avoid unsightly cracks and other
more serious structural problems.
According to the 2006 IRC, this 5/16-inch (minimum) steel angle
should measure at least 4 inches by 6 inches, with the long leg
oriented vertically and anchored to the framing (see Section
R703.7.2). The angle should be set to follow the slope of the
roof, with a small gap between the horizontal leg of the angle
and the roof deck.
To make installing the brick a bit easier, the steel fabricator
should add vertical plates in the crook of the shelf angle at
intervals along its length, which will resist the brick's
tendency to slide down the slope of the angle.
Another option would be to weld small angles onto the
horizontal leg of the primary, sloping angle; this will create
a series of small steel seats or terraces that the brick can be
started on. These stops are required by code whenever the slope
of the roof exceeds 7/12.
For brick veneer to be supported by wood framing in this way,
the IRC has a few requirements. First, the veneer must not
weigh more than 40 pounds per square foot, which shouldn't be a
problem with standard bricks but could be one with thicker
jumbo brick or stone.
Second, when the height of a brick-veneer wall above a steel
angle exceeds 12 feet 8 inches, the design must be approved by
your building inspector.
Third, if the brick is supported by a beam or header (for
example, if there is a door opening between the garage and
house), the live-load deflection of the header cannot exceed
1/600 of the span length. In this case, live load applies not
only to the normal forms like snow on the roof, furniture on
the floor, and people at a party, but also to the weight of the
supported brick itself.
The point of this requirement is to limit deflections that
might cause cracking of the brick.
Fastening Steel to Framing
While building codes permit the use of lag bolts into doubled
studs, I prefer to through-bolt the shelf angle into double
blocking between the studs. This connection is stronger, and
it's easier to hit blocking (rather than the center of a stud)
when drilling holes through steel and sheathing. There's a more
reasonable margin for error if you step the blocking down with
the slope of the roof and lay out bolt holes between the
This blocking needs to be adequately supported. If you simply
toenail or through-nail the blocking in place, the force from
the bolt could overwhelm the nails, and the blocking could slip
down the wall. So think of each double block as a little header
between studs, with jack studs supporting each end of each
If the block is close to the floor, run the jack studs all the
way down to the sill and fasten them to the wall studs with a
few nails to lock them in place. If the block isn't close to
the floor, pairs of 16-inch-long jacks fastened to the studs
with six 16-penny nails will handle more load than any one bolt
The appropriate bolt size and spacing depends on how much brick
veneer is to be supported by the steel angle. When choosing a
bolt size and spacing (see chart), keep in mind that smaller
bolts spaced closer together are easier to install than larger
bolts spaced farther apart, and are structurally
Flashing and Movement Joints
Waterproofing should consist of normal weep holes and flashing
at the base of the brick, coupled with step-flashing and
counterflashing directly from the roofing to the brick veneer
— similar to how you'd flash a chimney. This detail can
make the transition at the eaves a little tricky, but
A final requirement — one that many builders seem to skip
and many building officials don't seem to be aware of —
calls for vertical expansion joints to separate brick supported
by wood framing from any adjacent brick that is continuous to
— and supported by — the foundation.
To prevent cracking, vertical expansion
joints are needed wherever veneer brick supported by a masonry
foundation meets brick supported by wood framing.
To create a proper vertical expansion joint, lay up the brick
with a continuous unmortared vertical joint, then finish it
with a continuous flexible backer rod and compatible
These joints will ensure that whatever small movement does
occur in the brick over the garage will not cause cracking at
the transition to the adjacent brick supported on the
PE, is a structural engineer with
Palmer Engineering, in Tucker, Ga.