The philosophical questions become less of a debate the more
character-defining the stucco becomes.

My 1926 1.5 story California-style simulant Craftsman bungalow has brick
veneer on the ground floor and pebbledash stucco finish over wood lath on
the large aeroplane-style lookout roof dormer. It is a marvelous pebbledash,
using pinky fingernail-size quartz and black glass (mica?) chips embedded in
a brilliant white stucco. It must have shimmered like crazy in the southern
summer sun when new and before environmental grime dulled its luster.

At some point, the gutters were removed from the upper roof. Over the years,
the resultant waterfall bouncing off the lower standing seam metal roof
saturated the base of the stucco wall in two areas below upper valleys. The
stucco had completely failed at the lower extremities above the lower roof
counterflashing, exposing the lath.

It is clear that this material was never intended to serve as a sacrificial
material. Additional problems included the loss of adhesion of the chips to
the stucco as the stucco surface became more friable, with lots of chips
laying on the roof around the dormer.

My solution was to cut out the area of damaged stucco and replace it in-kind
after a search across Carolina for matching quartz chips, and a fruitless
search for mica or black glass (I ended up buying black glass votive candle
holders and smashing them in a bag with a hammer and running the result
through sieves until I had sufficient quantity of proper sized chips). We
matched the color of the new stucco to the interior color of the old sound
stucco. It was very much brighter than the grey the old had weathered to.
Yes, it looks new. Admittedly, it is not prominent in the public view of the
house, being on the rear sides of the dormer behind the cross ridge of the
main roof, and positioned low. But I would have chosen the same solution
regardless of where it was located. After 7 years, the brightness of the new
work has moderated, and it is increasingly blending with the old.

We then very lightly cleaned the stucco (a pretty ineffectual rinse, since
the surface was so compromised that no scrubbing could be applied; mostly it
was done to aid the penetration of the consolidant) and used a clear
breathable ProSoCo masonry consolidant for stucco on the balance of the
historic material. I have been very pleased with the performance of this
renewable product. Virtually no loss of chip material has occurred, and
after application, you could run your hand across the stucco with confidence
that the chips would remain embedded. It was advertised as needing renewal
every 10 years, and that seems about right. I am now seeing some loosening
of the surface.

Painting was not an option for this surface. Total replacement seems
irresponsible, and the original chip materials are not in my experience to
date entirely replaceable in kind.

That's my case study.
_____________________________________________________
Dan Becker,  Exec. Dir.           "Have nothing in your house that
Raleigh Historic                        you do not know to be useful
Districts Commission                or believe to be beautiful."
[log in to unmask]                                       -- William Morris
919/890-3678