Chicago is a masonry city
Yes, there thousands of wood frame buildings throughout our city, but when one travels the neighborhoods, it becomes obvious very quickly that this is a city built out of bricks and mortar. Competently constructed masonry buildings need very little repair or maintenance, but it sometimes becomes necessary to perform repairs. But Chicago is destroying it’s masonry. The problems come from how those repairs are performed.
- We use the wrong materials for repair. Our buildings were built with soft lime rich mortars, entirely unlike modern mortars. When you put the wrong cement on old masonry, it accelerates damage, it doesn’t fix anything.
- We waste money on “tuckpointing” when properly applied spot repairs are what’s necessary.
- We ignore lintels and smear cement over problems. Rusting lintels are one of the largest issues, and we ignore them.
- We wrap lintels with aluminum. This holds water into one of the most critical components in the building.
- We ignore critical flashing details and smear them with cement. Cement is not caulk; it doesn’t keep water out of buildings. (In most cases, neither does caulk.)
It’s better to do nothing
First, it is not necessary to “protect” the older mortars. If we don’t actively abuse our buildings by applying the wrong principles, materials, and methods, they will last. They have withstood thousands of years of use all over the world, and if the building is reasonably maintained, tuckpointing is most likely only necessary every 25-30 years at most.
I am proposing that it’s better doing absolutely nothing than it is to do the wrong things to our buildings. I’m going to break this down into component parts, the first one is my post on “What is Tuckpointing?“.
If you can find it, it’s a great read Volume XXIII (issue #3, 1991) of the APT Bulletin, The Journal of the Association for Preservation Technology.