Replacing old mortar for historic brick
The tuckpointing in your brick building is starting to decay. Cracks are forming and small chunks of mortar are beginning to fall out. Sounds like you’re due to take on the “not too difficult” but time consuming task of tuckpointing. Time to head on down to the nearest Home Depot or Lowes at stock up on tuckpointing supplies and ready mix mortar. Right? If you are tuckpointng an older building like those found through most of St. Louis City and much of St. Louis County, you just made a mistake.
The mortar found at most big box stores are mixes designed specifically to be used with modern brick. Modern brick is much harder than the brick found in most older homes. For various structural reasons, the harder the brick in use the harder the mortar should be. If you use a mortar that is harder than your brick, the bricks could begin to crack and break apart. With the two earthquakes and pair of accompanying aftershocks that recently struck the area, I hope these kind of issues get your attention.
The mortar you need cannot be found at Lowes or Home Depot. You need to head to a specialist. The only supplier I have ever used is F W Clemens at 3357 Gravois in South St. Louis. Its at the northwest corner of the Cherokee and Gravois. They have ready mix mortar on hand specifically designed to be used with older brick. This mortar, which runs about $6 a bag, has a higher content of lime than the more cement laden mortars commonly used today. It won’t cause your brick to prematurely break down and will improve the structural integrity and shock absorption capabilities of your brick building. Make the right move and play it safe.