Installing a Twenty-Foot Header - Continued
A bigger challenge was preserving the addition's clear-span
second floor with only 8 1/2 inches of depth to work with.
After consulting with a structural engineer, the architect
specified 8-inch steel C-channel joists on 12-inch centers; the
joists would have to be doubled up under the tub.
Manhandling the Steel
At 48 pounds per foot, our 19-foot 8-inch header weighed almost
1,000 pounds. We rolled it off the truck on PVC pipes to get it
into position, then used a chain hoist to raise it (Figure
Figure 5.A chain hoist attached to the temporary
ledger supplied lift (top photos). After the hoist maxed out, a
pair of heavy-duty ratchet straps finished the job
We strapped the chain hoist to the temporary 2x10 ledger, found
the balance point on the beam, and carefully lifted, keeping an
eye on our ledger and shoring as we went.
When it became obvious that we would max out the chain hoist
capacity, we finished the lifting with a couple of
1,000-pound-capacity ratchet straps.
The architect planned for the beam's support posts to bear on
the addition's new concrete foundation. This worked out well;
at a little over 8 inches wide, the I-beam wouldn't fit inside
the existing 2x4 framing anyway.
Once the beam was in near-final position, we slipped in the
4-inch-square columns and bolted everything together (Figure
6). We'd had the columns made to exact length, which made it a
little tough to get the beam into place. We used a post on a
bottle jack to lift first one end of the beam (and the house,
too) and then the other end, so we could get the column bases
Figure 6.Four-inch steel columns with welded caps
and base plates support the beam at each end. Note the
1/2-inch-drive ratchet's drift handle, used for lining up the
predrilled bolt holes (top). The column bottoms (bottom) would
be secured later with one 1/2-inch wedge anchor each; the
inside hole landed too close to the edge of the concrete for
We didn't have to worry about cracking the plaster in the bath
above as we jacked, because the whole space was being demoed
anyway. (Next time, as my fabricator suggests, we'll make the
posts 1/2 inch short to gain a little play, then add shims
underneath once the beam is in place.)
Only then — when the beam had solid bearing — did
we remove the ratchet straps. We checked the posts for plumb,
then installed a couple of wedge anchors through the base
plates into the foundation.
Installing Joist Hangers
Next we attached the existing second-floor joists to the beam.
To maintain a consistent ceiling plane, we jacked each joist
individually to the proper height, toenailed it snug, and
installed the hanger. We used a powder-actuated tool to fasten
the exterior wall plate above to the top of the header.
Finally, with everything secure, we took down the diagonal
bracing so we could frame the rest of the addition (Figure
Figure 7.The author used conventional face-mount
hangers nailed to the header to support the joist ends on the
existing part of the house (top). With the hangers installed
and the post bases fastened to the foundation, the ledger and
2x8 supports came down. The temporary wall was left in place to
keep the house clean and offer weather protection
Finishing the Framing
The rest of the framing was a piece of cake — except for
the time spent dealing with the steel floor joists (Figure
Figure 8.Eight-inch-deep steel joists on 12-inch
centers provide a clear-span ceiling in the kitchen. The
doubled joists on the right side of the photo at left support
the whirlpool tub. The steel band joist is visible between
If you're used to working with wood, steel framing takes a lot
more time. You cut with an abrasive cutoff saw, and all the
connections have to be made with an impact driver and
self-tapping screws. It took a while to align the precut holes
for plumbing and electrical rough-in, and we had to install a
row of blocking midspan.
Still, despite the complications, the steel joists were a
pretty good solution, especially considering we ended up with a
19-foot span that supports a tile floor and a 70-gallon
Cost of the Steel
The steel beam and posts cost about $1,200 and took less than
eight hours to install, including the time spent installing the
temporary bracing, plating the web, and preparing the
We hid the steel posts supporting the I-beam in the 2x6 walls
of the addition. The addition's roof and overhang details had
been designed to match the existing house (Figure 9), and once
the entire house was sided with vinyl, the addition looked as
if it had been there forever.
Figure 9.The addition didn't just furnish extra
space; it dramatically improved the appearance of the original
rear facade (top photos). Inside (bottom), the new
kitchen.Bjorn Billings owns Billings Carpentry and
Construction in Nyack, N.Y.