Last fall, my employer signed a contract to remodel a kitchen
in San Ramon, Calif. It was my job as project manager to work
out the details with the client and manage the actual
The home was a 1980s single-story contemporary with a long
bearing ridge and high vaulted ceilings. A wall approximately
14 feet wide by 18 feet tall supported one end of the ridge and
separated the kitchen from a family room at the back of the
house. Except for a soffit (which we planned to remove), the
only break in this vast expanse of drywall was a 5-foot-wide
doorway (see Figure 1). Although it wasn't part of the original
plan, the customers told me they were thinking about putting
French doors into this opening.
In the original house, built in the
1980s, a 5-foot-wide doorway linked the kitchen and family
room; the author suggested enlarging this opening.
I suggested increasing the size of the opening instead; this
would result in a better traffic pattern and give the kitchen a
more spacious feeling. It would also let in light from the
family-room windows and create a view into the landscaped yard
beyond. The owners liked the idea.
The only catch was that the wall carried a large section of
roof and was one of the major shear walls in the house.
Need for Shear Walls
Shear walls are designed to resist the forces exerted on
buildings by high winds and earthquakes. They resemble regular
framed walls but are secured to the foundation with heavy
hold-down bolts or straps and are stiffened by a layer of
plywood fastened with a specified tight nailing pattern. On the
West Coast, shear walls are the main earthquake-resistant
component used in residential construction.
We wanted to create a new 9-foot-wide by 8-foot-tall opening in
the existing shear wall, which required stamped drawings from
an engineer. I faxed elevations of the wall with the existing
and proposed door openings to civil engineer Lee McCleary, of
Walnut Creek, Calif., who laid out what it would take to open
up the wall.
I estimated the cost of the additional work, presented it to
the clients, and came away with a signed change order.
Existing conditions. The existing
shear wall was framed with 2x6 studs and sheathed on the
kitchen side with 3/8-inch plywood nailed 3 inches on-center.
It was supported by 2x8 joists and a sill that landed on a
concrete stem-wall foundation. In addition to studs and a
header, the wall contained three 4x6 posts connected to the
foundation with cast-in anchor bolts (Figure 2). Since they
would be in the way of the new opening, the posts and anchors
had to come out.
Figure 2. The wall
between the two rooms was a shear wall; it's shown here after
the soffit and some of the drywall and plywood shear sheathing
were removed. The 4x6 post to the left of the opening is tied
to the foundation by a heavy cast-in hold-down.
According to McCleary, we could take out part of the wall, but
only if we replaced the shear value of the area removed.
With the new, wider passageway, only 30 inches of wall would
remain at either side of the opening — far too little to
provide the necessary shear value with conventional framing.
McCleary's solution was to replace the end walls with
manufactured shear panels, factory-built wall sections that are
significantly stronger than site-built shear walls.
Shear panels are frequently used in high-wind and seismic zones
to stiffen "weak," narrow sections of wall, allowing builders
to devote more wall area to door and window openings. While
shear panels can be installed almost anywhere in a building,
the most common location is in the narrow section of wall on
either side of a garage door (Figure 3).
Figure 3. Manufactured
shear panels are made from either steel or a combination of
wood and steel. At far left, Simpson's Wood Strong-Wall panel
strengthens and stiffens a wall containing a garage-door
opening — a common application. In the project at left, a
Hardy panel allows the contractor to include more window area
than would be possible with conventional shear walls. In these
installations, the panels sit on a mudsill or directly on the
Several manufacturers make shear panels, among them Simpson
Strong-Tie, Hardy Frames, Shear Transfer Systems, Trus Joist,
and R.H. Tamlyn & Sons. The panels are made from wood with
a small amount of steel; from steel with a small amount of
wood; or entirely from steel. Stock-size shear panels measure
anywhere from 12 to 80 inches wide and from 78 to 153 inches
tall. For an extra charge, most manufacturers will produce
Since tract builders buy panels by the truckload, I assume they
get them at a good discount. A small builder should expect to
pay $200 to $400 per panel at a lumberyard or supply
In most instances, shear panels are bolted directly to the
foundation or slab, but on this remodel we wanted to attach the
shear panels to the wood floor to avoid the complication of
cutting out and resupporting joists. Although installation is
simpler and shear values are higher when you bolt panels
directly to a foundation or concrete slab, floor installations
are necessary when you're using panels on the upper levels of
At first, McCleary considered using Simpson's Wood Strong-Wall,
but when he calculated the load he found that any wood panel
wide enough to meet the shear requirement would not fit in the
available 30-inch space. And whereas the steel version of this
product — the Steel Strong-Wall — was strong enough
to work in the available space, it was not yet approved for
installation on top of framed floor systems.
The right panel for the job. Hence,
McCleary specified Hardy Frame Panels, steel shear panels
strong enough to replace the missing shear value, narrow enough
to fit the space, and rated for use over floors framed with
wood or light-gauge steel (see illustration). Steel panels are
stronger than similar-sized panels made from wood.
Had the end walls in this house been wider, we could have
chosen from a variety of wood shear panels, all of which are
rated for use over framed floors.
Since we wanted to complete the structural work as soon as
possible, we purchased all the materials in advance.
Fortunately, they were all stock items: two Hardy Frame Panels,
four lengths of 7/8-inch threaded rod, a 6x12 Douglas fir
header, a 6x8 Parallam to block joist bays, and multiple tubes
of Simpson's Epoxy-Tie Set adhesive.
As soon as we got permits, we began demolition. We had already
removed the soffit and enough drywall to see inside the lower
portion of the wall, but we were not certain what was at the
top. To be on the safe side, we assumed that the wall carried
the roof, and we made plans to shore it up before removing any
structural components. First, however, we placed the new header
against the side of the shear wall so that the shoring would
not interfere with our attempts to maneuver the header into
position (Figure 4).
Figure 4. The author's
crew used diagonal 2x6 braces to support the load above the
shear wall while structural work was under way. To avoid having
to maneuver the massive header through the braces, the workers
prepositioned it on the floor and built the shoring around
Shoring and demo. I picked a height
well above where we needed to cut the studs to insert the new
header and removed the drywall and plywood below that line.
Then we nailed horizontal 2x6 cleats to both sides of the wall.
Next, we wedged long 2x6 supports between the blocks on the
floor and the cleats on the wall and nailed them into place.
Since the supports came up at an angle, there would be room to
To prevent the supports from bowing, we tied them together with
diagonal bracing and ran perpendicular braces to the floor. The
shoring did not take long to complete and was quickly approved