Masonry Magazine August 1985 Page. 36
TERRA COTTA
continued from page 7
imbedded in a masonry mix. With time, water would penetrate and rust the metal which would expand and develop stresses in the terra cotta.
• Building facades on older buildings, in general, seldom are inspected and maintained on a regular basis. Because of poor maintenance of mortar points, parapet walls, flashings and built-up roofs, water entry problems are intensified.
These causes result in terra cotta deterioration which is visible in the following areas:
• Crazed and spalled glazes.
• Buckled blocks.
• Spalling at shelf angles.
• Cracks at building corners.
• Vertical cracks at piers.
• Damaged sills.
Some Specific Practices Used to Restore and Maintain Terra Cotta
In the past 10 years, a number of terra cotta buildings have been renovated. Figures 13 and 14 show the Sealy Mansion in Galveston, Texas, which used terra cotta elements from Ludowici-Celadon in its restoration. As a result, a number of techniques have been developed to inspect, analyze, repair and maintain the terra cotta facade. Since the cause of the problems are beneath the surface, each step should be executed.
Typically, the inspection will start out with a visual appraisal with a telescope or binoculars or it can be made from a suspended scaffold. Any crack or marked unnatural discoloration is noted. Major fractures are recorded via photographs. Areas that are suspect of further interior damage are then given additional inspection such as sounding (can detect internal web cracking), metal detecting using a pachometer to locate shelf angles and structural steel supports, and making inspection openings.
From the inspection data, the cause or causes for the terra cotta deterioration are determined. In some cases, this may require dismantling some terra cotta to replace, extend or add a shelf angle. In other cases, it may mean the repair of a water infiltration situation. In all cases, the repair or planned repair should be determined prior to replacing or patching the terra cotta.
If the cracks in the terra cotta are of a minor nature and offer no safety problem, they can be repaired using an epoxy injection technique. The thermosetting resin is in-
36 MASONRY-JULY/AUGUST, 1985