South Carolina State Museum

With so much history, careful attention to detail was required when a portion of the South Carolina State Museum was recently renovated. One hundred plus year old subfloors were an early concern in the project.

With more than 70,000 artifacts, the South Carolina State Museum calls the building in which it is housed its largest artifact. Built in 1894, the former Columbia Mill houses exhibits devoted to art, history, science, and technology. Listed on the National Register of Historic Places, the building was the first completely electric textile mill in the world and the first major industrial installation for General Electric.

Existing Substrate

While in surprisingly sound condition given its 100+ year age, the concrete was uneven and had a number of cracks throughout. Some areas of the concrete subfloor were damaged. Former dividing walls within the structure presented deeper subfloor imperfections with brick remnants left behind. As with many older subfloors, evidence throughout the space indicated past leveling efforts with varying degrees of success.


The floors are thoroughly swept with all debris removed. Loose subfloor materials are removed and trenches and open spaces vacuumed. Schönox SEZ Plus, rapid setting screed, is an ideal choice to fill voids and trenches.

Priming Using Schönox VD

The entire space is primed using Schönox VD, universal acrylic primer, increasing the adhesion of the leveling materials to be applied next. With a drying time of roughly 10 to 30 minutes, Schönox VD is rolled onto the substrate.

Schönox AP Application

Schönox AP, synthetic gypsum self-leveling compound, is mixed and poured within the renovation area. Dust-reduced properties within the product keep dust to a minimum within the Museum. Schönox AP flows into the subfloor imperfections with a smooth, efficient consistency.
Gauge rakes are used to distribute the leveling material throughout the renovation space. Pre positioned barriers provide a finished transition between the renovated space and existing floor areas.

Rennovated Subfloor

Before the subfloor project, the substrate was not suitable for any floor covering. The Schönox AP will be ready for flooring installation in roughly 24 to 48 hours.