My wife and I recently
bought an old 1872 Victorian home that as you can imagine needs a lot of work.
We are interested in keeping the historic integrity of the house. The largest
concern right now is the exterior of the house. It is currently an aggregate
stucco exterior that is in very poor condition. Our concern is the renovation
of the exterior. In order to keep the historic integrity do we need to
re-stucco with the same aggregate look (little stones mixed in with the stucco)
or can we either re-stucco with a smooth finish, or can we replace with cedar
clapboard? If we re-stucco, does the color matter? —Wilmington, Delaware
To keep the building's architectural character you will want to repair and
preserve the original stucco if possible. If not, complete replacement with an
exact or near match would be acceptable. Replacement with cedar siding would
change the character of the building dramatically. The color can be as
important as the texture, but realize that the color may have been changed with
later coatings or paint.
"Stucco" is a type of exterior plaster applied as a two- or
three-layer coating directly on masonry or on wood or metal lath that is
fastened to the wood frame structure beneath. In the 18th and 19th centuries
stucco was made of lime, sand and hair troweled onto masonry walls as a
weatherproofing skim coat. It was usually applied with a flat and smooth
surface sometimes tooled and troweled to simulate more costly stone masonry. By
the 20th century stucco was more commonly formulated with Portland cement and
lime, making it more durable. It was applied in two or three layers on a system
of furring and metal or wood lath making it an integral part of the wall
system. By this time a variety of additional novelty finishes and textures were
used, including Spanish adobe, pebble-dashed or dry-dash surface, fan and
sponge texture, and roughcast (or wet-dash), each with its characteristic
appearance.
It is important to assess damage and determine the causes. Water leaks in
cornices above or rising damp from below are the probable causes of damage.
Reduce or eliminate these sources of moisture before repairs are made or
complete replacement is considered. Shifting foundations or changing structural
loads within the building may be causing cracks in the stucco. Call in a
structural engineer before stucco repairs for a structural assessment if you
have cracks wider than 1/8".
Repairs should duplicate the original methods and materials. Successful stucco
repairs require the skill and experience of a professional plasterer who
understands the original stucco system and materials used. It is possible to
repair up to one-fourth of a wall at lower cost than complete replacement. If
you decide for complete replacement be wary of Exterior Insulation and Finish
System (EIFS). This system of materials and methods was recently developed for
modern buildings and even on them it has a reputation for costly failures.
For more information consult the 16-page Preservation Brief #22, “The
Preservation and Repair of Historic Stucco,” available online at
http://www.nps.gov/history/hps/tps/briefs/brief22.htm.
Tar on Sandstone
How can I remove drips
of tar from my sandstone steps? —Omaha,
Nebraska
If the tar drips are recent and have not soaked deeply into a porous stone
surface, just pop them off with a putty knife on a sub-zero day in the middle
of the winter. Has spring already sprung in Omaha? If so try a preliminary application of
dry ice to freeze the tar. This method may leave some tar residue. To remove at
least some of the residue let the stone dry out, cover with a couple layers of
absorbent cotton cloth and heat carefully right over the spot with a hot
clothes iron. The tar should soak up into the cloth. As always, test first in
an obscure location. Any solvent method is likely to make the tar soak deeper
into the stone.
Window Glazing
I will soon be
replacing broken lights and reglazing 50 windows. I would like to know how to
take out old hard brittle window glazing without breaking the glass. Also,
where can I get old bubbly, wavy glass in various sizes?" —Athol, Massachusetts
Heat methods work best and fastest. When brittle glazing putty is heated, it
softens up quite quickly. It can then be easily scraped away. For this work I
use a Makita heat gun (model HG1100, about $80, with the separately available
flat nozzle) and a pull-type scraper (Embee Molding Scraper Set, No. 1240,
about $15).
When working with heat methods always remove the sash from the frame and work
outdoors or in a separate shop building to reduce the risk of fire. Since you
are doing so many windows it will be worth setting up a shop or work station
that that has everything you need to make the job easy. Set up a bench that
holds the sash up at an angle with the center of the sash at about elbow
height. Removing putty and paint from the sash generates hazardous
lead-containing dust and debris. Use a rated respirator, wear a hat and remove
your clothes after each work session and take a shower. Wash the clothes
separately and give the washing machine an extra rinse cycle after removing the
washed clothes. Keep your work area clean with a HEPA rated vacuum machine.
Adjust the heat gun to the lowest temperature that softens the putty. The
maximum temperature will make the work go faster but it is so hot that it can
vaporize lead in the glazing and paint, creating an additional health hazard.
Lay the wide nozzle down on the glass right along the base of the glazing and
shift it up along the glazing as you scrape away the softened putty just
heated. The hot air will crack the glass if it blows directly onto it. Make a
heat pad to protect the glass on the other side of the glazing from the hot
air. Cut a piece of cardboard (off the back of a pad of writing paper) to about
1/8" less than the size of the exposed glass and wrap the cardboard with 3
or 4 layers of aluminum foil. Lay the pad on the glass on the other side of the
glazing to protect it from the stream of hot air. With this method we usually
have less than 10% breakage.
Our best and lowest cost source of glass is from all the old windows that are
removed by the window replacement companies. Usually they are free for the
taking right at the site. Of course, you have to deglaze and clean up the glass
before you can use it.
Contact John Leeke
directly for answers to your questions and more information on techniques for
restoring and maintaining your historic building. Write to John Leeke,
Preservation Consultant, 26
Higgins St., Portland Maine 04103;
(207) 773-2306; or by email at johnleeke@HistoricHomeWorks.com.
