Wednesday, October 15, 2008

HAMILTON GRANGE: Restoration Update October 2008

The Hamilton Grange restoration team has spent the past month uncovering
remaining historic evidence of the home’s original roof details. Based
upon this evidence the National Park Service (NPS) proposes to replace the
flat roof with non-historic material and to install stained wood shingles.

Details Emerge from Original Roof

When constructed in 1802, the Grange’s roof was flat and surrounded with a
lower (hipped) roof. We do know that the flat roof failed very quickly, as
the nails that were used for constructing the replacement hipped roof date
to approximately 1815, 13 years after the Grange was built. The only
definitive evidence we found of the original flat roof were small wrought
flashing nails, lead flashing, sealant, sheathing nails and balustrade
(decorative railing) base nails. Even with this evidence, we unfortunately
are unable to conclude what the original flat roof was actually made of.
Options from Hamilton’s day would have included wood shingles, lead sheets,
tin plates or canvas.

Since we cannot conclude what the original flat roof was made of, and given
the uncertain performance of any of the historic options, NPS is proposing
to install a roof made of modern materials that will ensure weather
tightness. The new roof material, which will be a synthetic membrane, will
match the off-white appearance of the historic wood shingles (ranging in
width from 2-3/4" to 5," with 4" exposed to the weather) previously found
on the sloped portion of the roof – see September 2008 update.
Additionally, we consider it possible that the roof’s balustrade, which can
be seen in a circa 1860 photograph, is not the original balustrade, and in
fact the original main roof balustrade may have been placed around the
perimeter of the flat roof, connecting the four chimneys on their inside
edges. The balustrade base nails (two large 6" wrought spikes spaced every
15-16" along the flat roof beams), completely flashed over at the
intersection of two flat roof beams, were instrumental in our
re-considering the location of the original main roof balustrade. The
spacing of the double nailing correlates with the balustrade newels and
intermediate bottom rail support blocks.

Temporary Reconstruction of Original Stair Components

When the Grange was moved in 1889, the original stair hall was reconfigured
to accommodate a new front door (the original faced St. Luke’s Church).
The reconfiguration entailed the replacement of the 1802 stair case, three
runs of stairs with two intermediate landings, with a new staircase of one
long run, a short run and one intermediate landing. To our great surprise,
and appreciation to the 1889 carpenters, replacement stairs used all of the
original stair carriages and one of the original landings. Last week we
“temporarily” reconstructed the original stairs, in order to determine the
extent of missing pieces, and verified that the re-used landing was in fact
the original.

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