by Tim Meehan
Stowe, Vt., is a classic New England town. One of its oldest
and most visible structures is the historic Stowe Inn, located
near the center of the village. When its owner decided to
expand the dining room by adding a large wraparound porch, I
was glad to get a call to discuss such a highly visible
Because of the building's historic status, the town's historic
preservation commission insisted that the porch look like it
had been around for a long time. Accordingly, the architect
designed a porch reminiscent of those from the late 1800s. Most
notably, the design included a rounded outside corner, a
signature Victorian element.
Other than the curved corner and a barrel vault over the inn's
front door, the porch design was conventional. We built a 2x10
pressure-treated floor system supported by 6x6 posts bearing on
concrete piers spaced about 8 feet apart. To support the joists
at the curved corner, we glued up a rounded girder from six
layers of 1/2-inch pressure-treated plywood. The joists bear
directly on this girder, and terminate in a curved band joist,
which we laminated from three layers of 1/2-inch PT plywood. We
also placed posts and girders near the building, so that most
of the loads from the deck — which would support 100-psf
commercial loads — would be carried directly to the
ground, not to a ledger attached to the building.
We spent a little extra time laying out a double floor joist
coming off the building's outside corner at 45 degrees —
or as close to 45 degrees as we could make it, given that the
old building was not perfectly square. Since we planned to lay
out the roof framing above from the same diagonal reference, we
wanted it to be accurate.
To support the porch roof, we attached a ledger to the solid
brick building with a combination of 3/8-inch lags and lead
shields and epoxied threaded rod (1). At the eaves, we used
three-layer built-up 2x8 beams for the straight runs and a
laminated beam for the radius, all supported by
fiber-reinforced synthetic columns.
Laminating a Curved Beam
While the crew worked on the straight sections of the roof,
lead carpenter John Morin made the curved beam, using the same
method he'd used to make the curved girder for the floor (2).
He first did the layout on the plywood floor of our shop, using
a trammel arm, then screwed 2x10 blocks to the floor, which
provided the formwork for the six layers of 3/4-inch CDX
plywood. Given the relatively large curve, we didn't think we
needed to compensate for spring-back, so we simply used the
9-foot design radius, figuring we could persuade the beam ends
into position with clamps.
We let the glue dry for a couple of days, then delivered the
beam to the job site in our stake-body truck and had a crew of
four lift it into position. A plumb bob helped us line it up
with the curving band joist below. Once the beam was level, we
clamped it in place and marked where it would tie into the
straight beams (3). As expected, we had to do a little prying
and clamping to get the beam in its final position.
We removed the beam and Morin made stepped cuts on both ends
using a circular saw, a recip saw, and a chisel (4); he also
made corresponding cuts at the ends of the straight beams (5).
We covered the mating surfaces with a thick layer of
polyurethane glue, then pulled everything together with clamps
Round Roof Framing
The next day John removed the clamps and went to work on
framing the roof. He positioned the top end of the first rafter
at the outside corner of the ledger (7), then used a plumb bob
to line up the rafter tail with the diagonal floor joist below.
This placed the first rafter in the center of the arc, where a
supporting column would be located. For the rest of the
rafters, John made long cheek cuts that tapered anywhere from
3/4 inch down to zero.
We spaced the eaves ends of the rafters 20 inches on-center (8)
so the segments of plywood sheathing (9) would be the same size
and shape as the standing-seam panels that would ultimately
cover the roof. Matching the sheathing and the steel panels
minimizes oil canning, the distortion in standing-seam panels
that can be made worse by uneven substrates.
Soffits and Trim
With the roof framed, we moved on to the soffit and fascia. For
the curved sections of the soffit, we used segments of 1/4-inch
AC plywood, first scribing the joints in place to get a tight
fit (10). We then used a simple site-made compass to mark a
fair curve on the outside edge (11), and finished up by
grinding and sanding to the line (12). We secured the soffit
with polyurethane glue and finish nails.
We used cellular PVC boards for the curved fascia. We left the
material in direct sunlight for a few hours, which increased
its flexibility enough that we were able to make the bends
We used similar methods to frame and trim the porch's curving
half wall. We framed the 2x6 walls with plates laminated and
routed from 3/4-inch plywood. For the frame-and-panel
treatment, we used 1/4-inch MDO for the panels and primed pine
for the frames. A panel molding hides the gaps between the
frame and panel.Tim Meehan owns Northern New England Homes
in Stowe, Vt.