Due to the importance of the tower foundation issue, it is essential that long-term monitoring be conducted. Better data are needed to determine the best course of action for addressing the tower foundation issues, and to ensure the movements are not increasing and becoming more critical. In the meantime, the structural damage already incurred must be addressed as soon as possible. These, in turn, are a threat to the integrity of the church and its priceless contents, especially the historic stained glass windows.
A Cyclical Fluctuation
From 2009-2011, a 15-month monitoring was conducted by CCS Group Inc. of Chesterfield, MO. Contracted by the Archdiocese to help ascertain the rate of movement of the steeple, the study was also to evaluate any change in the structural damage due to this movement.
This new study is more extensive than the previous 5-month study (performed in 2005), which was not long enough to capture the seasonal effects. The new data shows that the displacement is cyclical in nature, most likely due to seasonal conditions. In fact there was a separation of the tower from the nave, but the rate of separation seems to be much lower than the previous projection. “The continual movement was not significant enough to be readily measurable over this time period,” and that “it is not a primary concern at this time,” according to the report.
The recommendations contained in the report are two-fold: continued monitoring of the movement for the long term, and address the damage already incurred.
Although this study concludes that “global structural failure of the bell tower or nave structure does not appear to be occurring at this time,” it would seem prudent and necessary to conduct long-term monitoring to obtain better data so as to determine the most cost-effective foundation repair in the future.
According to the recommendations of this study, addressing the building deterioration is the primary concern at this time. Numerous cracks which have developed over time in the masonry require tuck-pointing and repair to avoid further damage, and the integrity of the historic stained glass windows require immediate attention. Some of these, such as repairs of cracks in the masonry, securing of endangered stained glass windows, repair of other stain glass windows, we had already begun to address and some of them even successfully remedied.