Here is a contrasting
two-color arbor with MR. DECK's copyrighted
poppy-top canopy. The original
version of the Poppy-top arbor is the Hambly
Project. However, that structure was mounted onto a 2-story wall.
Here the structure is mounted onto the house-beam (6x12 glulam
under
the eave) which supports the
porch roof and not set upon the roof as it appears to be.
The radial
rafters are carved from kiln-dried doubly-stacked 6x12s 24-foot
long Douglas fir timbers,
painted a color called Behr's "volcanic island". The radial lath is
tan colored hollow PVC plastic 5x5s, 4x4s and 2x4s with end-cap inserts.
This
structure is enormous -- it has a 180º radial canopy with a 24-foot
radius. According to my calculations, that's over 900 square feet.
Even though they were
kiln-dried, each one of those four radial
rafters was so heavy I couldn't even lift one end up 6 inches above the
ground with a two-handled belt (and that was limited to how much height
I could get from just straightening my legs) -- I had
to use a mechanical hoist and two furniture dollies to just move them around. That should give you some indication of just how
huge those
radial-rafters are. But once they were put in place, they didn't appear
big at all. In fact the arbor looks to be perfectly sized for the large
house -- it just blends right in.
Incidentally, that's a
big mistake
most contractors make: they tend to
undersize the arbor
to minimize their costs. And after it's built, it looks skimpy and the
customer's stuck with it.
Observe the
shade cast by the canopy over the porch at 2PM PDT. Because the sun
rises in the front of the house, the arbor shades a large portion of the
adjacent pool apron for most of the morning -- which makes having
morning coffee by the pool a very comfortable experience.
People
outside California have no idea about how hot the summer sun gets here,
even in the mornings, unless of course we have fog overnight. And once
that burns off, its right back into broiler sunshine all day long -- and
the heat is especially strong over an unshaded concrete patio.
Here's the problem addressed
by this design:
The porch
ceiling is 9-foot 10-inches high and both the windows and glass doors are
8-foot high. The view from inside the house has a spectacular view of
the Santa Cruz mountains to the west, but since the sun sets in the
west, the afternoon sun was blinding this magnificent view of the
horizon from the interior. So it was necessary to shade the 12-foot deep
porch with an additional 24 feet of canopy and do it in such a manner as
to not obstruct the view of the mountains from the house's interior.
This
design solves that problem in a spectacular way. The underside of the
central arch is 9-feet 4-inches above the raised porch and projects
shade over the windows and doors in the late afternoon, yet does not
interfere with the view of the horizon. And the span between the columns
is 17 feet so the columns don't squeeze the magnificent panoramic view
from the center of the covered patio.
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Structural
Details
A special
bracket of Mr. Deck's design and engineering for fastening the radial
rafters to
the hidden porch beam was fabricated especially for this project. The attachment of the arbor to the house required a horizontal radial
strut and vertical stub post to support each radial rafter 3
inches above the
highly pitched roof's surface. The bracket was a crucial item in
achieving this design.
As these
radial rafters' interiors dry out over time, a tremendous warping force develops
within them, particularly in these long timbers. To prevent these long, tall
rafters from warping, two heavy-duty strap-brackets, hidden from view,
tie together the top-ends of the rafters to keep them from curling on the upper
portion.
To prevent curling of the rafters at the lower ends,
each
rafter was anchored to its supporting column by a 30-inch
long, 1-inch diameter threaded steel rod piercing the rafter beam from the top
and penetrating the concrete-encased pressure-treated 6x6 post within the column by one
foot.
The
columns are precast 12-inch diameter hollow concrete columns with seams,
backfilled with ready-mix concrete.
Observe the invisibility of the seams (trade secret). That in itself takes a number
steps over 10 days to accomplish.
Pyramidal caps
were placed atop the columns to facilitate rain run-off and to prevent
birds from nesting in that otherwise flat environment.
Those pyramidal caps didn't come with the columns but were built
in-place with a fast-setting
concrete after the rafters and arches were already connected to the column's
totally hidden
internal 6x6 post. And the poured caps are internally laced with galvanized
1/4-inch wire mesh to prevent them from cracking.
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Lighting
Details
The 3 major arches
each have 4 recessed 12-volt 20-watt halogen lights and the 2
half-arches on the extreme sides each have 2 of these recessed lights. The circular purlins near the roof-line have
a total of 6. Further, the radial-rafters each have 2 of these same
recessed lights, one on each side of its supporting column, to highlight the
column fore and aft. That makes a total of 30 recessed 20-watt lamps in all.
These are powered by two 300 watt transformers hidden in the attic on
two distinct circuits. Yet not one wire is visible anywhere.
In addition,
each arch supports one 120-volt 100-watt hanging outdoor lamp at its
center. The lamp's pearled-glass lenses are lit with a special 100-watt
halogen bulb for better illuminating the pearled glass -- ordinary bulbs
just don't have the intensity to do the lamps justice.
Both 12-volt
and 120-volt circuits are on dimmer switches controlled from inside the
house.
The
concentration of the six 20-watt halogen lights within the 4-foot radius of the
circular purlins near the roof-line (above) provides a much-needed circle of
lighting in the center of the porch to preclude a multiple shadowing
effect that would otherwise occur from all the peripheral lighting in
the arches.
Another
special treatment is the opposing tilt of the recessed light on the
upper slope of each rafter-beam. In order to get the light to shine back
onto its supporting column, the lamp had to be recessed at twice the
angle of incline of the rafter, but in the opposite direction.
Consequently, there is a double recess for each of these lights, one to
accommodate the lamp's cylinder and a smaller one to accommodate the
light's lens which is usually surface-mounted. No easy task.
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To prevent
rain-splash from causing dry-rot in the portions of the rafters above the roof-line,
the radial-rafters were clad with galvanized sheetmetal on the
horizontal top, back and under
sides. The entire hidden backside surface of the left- and right-most
radial-rafters that sit above the gutter were also clad with
sheetmetal. All this sheetmetal was then painted the same color as the
exposed wooden surface so as to not be recognizable as such.
The wooden
arches have a 6x8-inch cross-section and span
17 feet 8 inches, something that's not feasible with a straight 6x8.
All of the
wooden arches are clad top-side with C-channel 1/8-inch thick PVC plastic.
The radial rafters have each been capped with a continuous ribbon
of galvanized sheetmetal and then painted the same color as the rafters
themselves. With all the radial lathwork being colored PVC plastic,
the entire canopy is weather- and color-protected and hence involves
only minor annual maintenance.
The two side
sections have a special arrangement of the radial lathwork as seen here
to the right. This design was necessary to bring the lath-work into the
flat wedge-shaped opening on one plane as far as possible and still be able
to fasten their ends. The strong curve in the crook is not necessary but
just a designer detail to give it flare.
If I didn't
mention all these considerations, you might never appreciate the hundreds of
seemingly minor details that go into constructing something like this because they're neither visible
nor obvious.
In fact, given the
design plans, this structure looks like it would be rather easy to build.
But
none of this stuff is ever easy or straight-forward to do; it always takes me
way more time than I ever estimated even though I engineered it in the first
place.
A structure
like this, with all the lighting, costs
around $60,000.
So for a project of this magnitude, don't come to me with a meager
budget. I'm not going to tolerate price-intimidation or rudeness from
anyone.
