Residents of Seattle benefit from a rich architectural history in its built environment and the preservation and restoration of its historic structures is an ongoing community effort. One of the foundational principles of historic building restoration is to maintain fidelity to the existing historic fabric of the structure. However, this principle is not always practicable when the original building material of a structure requiring restoration is no longer available or in use in modern construction. In these instances, preservationists will employ alternative materials such as concrete and partner with commercial concrete contractors in Seattle to promote the historic character of their city.
Common types of concrete used in restoration
Concrete is a common building material used in historic preservation and restoration projects due to its versatility and durability. These characteristics are fundamental to historic building restoration as it is important to match the aesthetic of the existing material and to create repairs that strengthen the structural integrity of the building while lengthening its life cycle. Three popular types of concrete used for these purposes are precast concrete, dry-tamped cast stone, and glass fiber reinforced concrete.
Precast concrete is an ideal alternative for stone or terra cotta masonry and is made by casting wet concrete into molds, creating discreet masonry units identical to the existing historic building material. This is achieved by making rubber molds from the original masonry and applying pigments to the concrete mixture or staining the cured concrete to match the coloration. Precast concrete has several advantages such as its easy production process, minimal shrinkage after being cast in the molds, similar thermal properties to the masonry it is replacing, and its load-bearing properties.
Dry-tamped cast stone
Dry-tamped cast stone is similar to precast concrete but is made with an almost-dry cement, lime, and aggregate mixture. This mixture is tamped into molds created in the same fashion as precast concrete molds and yields a dense stone-like unit. Dry-tamped cast stone is often used as a replacement for brownstone or sandstone and is most seamlessly integrated into the historic structure by creating multiple, differing molds in order to replicate the natural variations of the existing material.
Glass fiber reinforced concrete
Glass fiber reinforced concrete (GFRC) are not appropriate for load-bearing applications, but are ideal for the aesthetic elements of a restoration project such as cornices, finials, or window and door trims. GFRC is made by spraying a lightweight concrete mixture reinforced with glass fibers into molds that, when finished, result in thin-shelled concrete panels. This fabrication method lends itself to highly detailed surface textures and therefore can be used to replicate a variety of building materials, like stone, terra cotta, metal, or even wood.
The Conco Companies’ mission is to be the best supplier of concrete services in the Western U.S. and to bring expertise and incomparable quality to each project. We continue to upgrade and expand our facilities to better serve the growing market for commercial, educational, parking structures, public works projects, and other development. Contact us to learn more about the services from one of the most trusted concrete contractors in Seattle.