Tuckpointing: a much-needed major undertaking

Why now?

Average life span of lime-based mortar is 25 years.
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Our beautiful church is a stunning sight from a distance, but up close, a visitor sees that after enduring many years of our weather in Saint Louis, this great edifice is in need of much repair and restoration. At this moment, the need of the hour is to take care of grave tuckpointing issues all over the exterior of the church.

When the Oratory of Saint Francis the Sales was finished in 1908, the entire façade was new. Since then, because of weathering, the mortar between the bricks and in the joints between large blocks of terracotta have eroded to the point of allowing water to seep into the structure. In addition to this, there are many places at which the terracotta has fallen off leaving large gaping holes permitting water to intrude behind the façade. The mortar has degraded in so many places on the façade that it is only a matter of time before the water intrusion will irreparably damage the interior of our beautiful church. These issues have to be addressed now as the situation has become critical. The average span of lime-based mortar is 25 years.

All masonry exteriors of brick-and-mortar structures require re-pointing periodically throughout its life. Re-pointing, or the more specialized technique of tuckpointing, repairs and renews the mortar that holds the bricks and stones together. Without this periodic maintenance, the mortar will eventually deteriorate, leading to water seepage and possibly crumbling destabilization of the walls. Tuckpointing of historical buildings requires even more attention to preservation and aesthetic aspects, especially for buildings that are subject to harsh weather.


Process

The process of repointing of the façade involves removing the old worn out mortar and filling the gaps with new mortar specifically produced to match the type, color and texture of the existing mortar to ensure compatibility of materials and avoid unsightly visual aberrations. The first step is to do a mortar analysis where a sample is taken and examined to identify the components, ratio and aggregate. Then the degraded mortar is removed to a depth where sound mortar is found.

Removal of old mortar has to be done by hand so as to avoid any damage to the existing masonry. This is exacting and labor-intensive work, but is necessary so as to have a good foundation for the new mortar. The new mortar is then laid into the joint, in several passes with time for curing if the amount of mortar removed is significant. The mortar is then given a rectangular profile so that it bonds with the brick. Finally, it is finished do make it visually appealing.


Damage to be repaired

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This image on the right shows the brickwork, and some of the wear and tear that must be fixed. The wear and tear seen here is typical of what is found all over the façade.

 

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In 2013, some emergency repairs had to be done to prevent an imminent collapse of a large part of the façade. Due to lack of funds at the time and the emergency nature, the repair of 2013 will have to be reworked. It is important that the upcoming repointing work be done properly so that it will last. As seen below, the damage in this case was quite extensive.

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The terracotta joints of many of the stained glass windows have to be fixed as can be seen here.

The terracotta joints of many of the stained glass windows have to be fixed as can be seen here.

Many decorative elements in terracotta have broken off and need to be replaced.

Many decorative elements in terracotta have broken off and need to be replaced.

The stress produced on the façade by the destabilized bricks and terracotta can crack the façade as seen here.

The stress produced on the façade by the destabilized bricks and terracotta can crack the façade as seen here.

Some of the damage to the façade is due to lightning strikes.

Some of the damage to the façade is due to lightning strikes.

 
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The white substance on these interior walls are evidence of spalling inside the steeple due to water having entered between the brickwork and washed out the mortar between the joints.


Proposal

We need your help in repairing the façade and to prevent further damage to the church. This work will be done in two phases.

Phase I

Repointing the entire steeple, including the scaffold rental for several months

During this phase, we will have to rent scaffolding to surround the 300-foot steeple for a few months, while the masons work on repointing the entire steeple. To save money in the long term, we will take advantage of this scaffolding to repair other elements of the steeple, such as the capitals, the clock in the steeple, and also various copper finishings like the gargoyles and roofing elements.

Phase I cost: $2 million.

Phase II

Repointing and cleaning the rest of the façade.

The church building is 231 feet long, 123 feet wide at the transepts, and 150 feet high including the roofs. The walls are only 73 feet high.  Therefore, scaffolding will not be needed for this phase. Despite the larger surface area, the cost of tuckpointing will be lower.

Phase II cost: $1.2 million. 

Total cost of tuckpointing the church building: $3.2 million.

Given that there are almost 4 million bricks in the façade, the cost of tuckpointing the entire surface comes to less than a dollar per brick! We count on your generosity to help us achieve this important goal to preserve this beautiful gem, the “Cathedral of South Saint Louis".