|This nice old dome had
been patched quite a few times since 1910. Some of
the patches were really well done, like where this band
||Most of the paint
was easily scraped off. A long as we are down to
the unpainted stucco, we can permanently bond a new
coat on top.
|Where the dome was re-coated before failed,
the mortar was easily scraped off. They didn't know the secret of Flex-con.
|The stucco was done over gypsum blocks, known
as "gypblock". These were really made for interior use.
Without tearing the whole dome down, we had to find a
practical solution for a permanent repair.
|A close up of the gypblock shows it was reinforced with
straw. Gypblocks are cast molding plaster, like is used for
interior plaster moldings. Some of these gypblocks were made
right at the job site, by the plasterers. Some were made by
manufacturers, like US Gypsum.
||Most of the paint is chipped off using an
electric chipping hammer. The chips open the pores in the
old stucco for a good bond.
For more about re-coating stucco, please click here.
ABOVE: All the holes and gaps in the gypblocks are packed with mortar with plenty of Flex-con mixed in. The flex aids not only in bonding, but the mortar develops incedible strength and crack resistance. The wall will be coated with the
same flex-con mixture. The flex-con also makes the mortar a lot less porous, and water resistant.
For more about Flex-con and chemical bonders,
Please click here.
LEFT: The ladder we climbed every day to get to the dome.
|Brown coat on the dome
||The stucco at the bottom is cut off to insert a metal
|The flashing overlaps the
rubber membrane below, and is over lapped with mortar.
coat is REAL white portland cement and REAL white sand.
After the window returns are finished, we put the finish on
the big wall.
|Dome finished to it's
original 1910 splendor.
I hope it lasts longer that 100 years this time.
|With a new copper cupola, and
new stucco on the dome, Capitol Hill Seventh Day Adventist
lights up the corner of 10th and Massachusetts Avenue, NE, Washington, DC.