Updated: Oct 16, 2021
Oftentimes I walk around Madison and see repairs to masonry that stick out due to the mismatched color. Oftentimes these homeowners or building owners hire contractors that lack the experience to identify mortar types and colors. Using the wrong mortar can be costly as it begins to fail after a few years due to the incompatibility.
Short History of Mortar
There are Portland cement based mortars and then there are lime putty based. Lime putty mortars were almost exclusively used prior to 1930. Lime putty mortars date back more than 4000 years and are still relevant to some historic structures right here in Wisconsin. So what's the difference between the lime putty and Portland based mortars. Lime Putty mortar is a mixture of local sand and limestone that was heated in a kiln to activate it. The lime was then mixed with water and was tended to for hours before being mixed with sand loaded into wooden buckets and carried to the masons. This lime mortar was pliable and allowed for structures to move over time. The properties of a lime mortar allow it to repair itself as the building settles over time making it a long lasting mortar with proper care. Today we have introduced Portland Cement to lime and sand to make mortars. When they cure they are subject to cracking and moisture intrusion if movement of the structure happens. When not taken care of in a timely manner the cracks get exponentially worse. Portland based mortars are hard and stiff and should not be used in conjunction with a structure built with lime putty mortar as they are not compatible. Knowing the difference is key to a long lasting repair.
Repairing historic structures is a specialty that sets us apart from most masonry contractors in our area. From decades of experience we have been able to make repairs that don't stick out but blend to the surrounding and last as long as they should. We want to make sure that the right materials are used and that they are properly prepared. Masonry is an artform and like an art form there is a specific way that repairs need to be done to ensure they last. Using different blends of sand and lime putty you alter the final color of the mortar. Irox onides can be added to mortar mixes to make a wide variety of colors.
Matching mortar colors takes time to learn and apply properly, so with our 40 years of experience you're sure to get the best results. Our goal is to provide you with the longest lasting repairs that blend in. We take pride in our work and take the time to ensure our customers are happy with the results.