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About Marion: |
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| About Marion, Inc. |
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Over the past 32 years, Marion, Inc. has earned a reputation as one of the region’s top masonry restoration firms. We are uniquely qualified to take on complex restoration projects that demand sophisticated craftsmanship and an understanding of historic materials and techniques.
When you hire Marion, Inc. for your project, you are assured of having a knowledgeable, thoughtful team that will guide you throughout all stages of the restoration process. |
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| Why does historic masonry require different care than modern masonry construction? |
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Historic masonry construction is fundamentally different from modern masonry buildings in several important ways:
-First, historic brick is softer than modern brick because modern brick is fired at a much higher temperature than was possible in the past. Abrasive cleaning, sealants, inappropriate chemical cleaning, and rigid cement mortars and parging will damage softer historic brick and stone.
-Second, historic buildings were built with lime mortars, so installing a cement mortar will lead to damage and deterioration. Portland cement--which is harder than traditional lime materials--is used in most modern buildings, but it wasn't even available in the United States until 1871.
-Third, historic masonry buildings were designed to breathe, i.e. absorb water and then release it, as opposed to modern building technology, which emphasizes waterproofing. The use of sealants and rigid, impermeable mortar in historic buildings disrupts the breathability of the walls. Water will become trapped in the walls, and this will cause deterioration of the masonry and interior finishes.
-Finally, modern buildings incorporate "control joints" which are regularly spaced vertical caulked joints that accommodate building movement. Because of the control joints, the mortar does not need to accommodate building movement. By contrast, the soft mortar in historic buildings provided the accommodation for movement, so control joints weren't necessary in traditional construction. When a rigid mortar is used in a historic building, the structure no longer has accommodation for movement. This leads to cracking and spalling of the masonry. |
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