Crypt Waterproofing Project

The waterproofing project was about an old coal storage area of a listed church adjacent to the crypt. The room in question, about 4 metres underground was used as coal storage, used to heat the building during Victorian times.

The 150 years old coal storage was leaking badly, and due to liquid water ingress became practically unusable. Moreover, the water that found itself into the room started affecting the adjacent crypt.

About 3 years prior to Core Conservation's involvement in the project, there was an attempt to stop the water ingress using modern cement tanking. The intervention was unsuccessful and the dampness problems have returned shortly thereafter. A more robust solution had to be found and being a listed church, the solution ideally had to be conservation-friendly.

The client came across Core Conservation's Roman lime solutions online and reached out to us. After an initial survey aimed to determine the extent of the problem, the initial renovation specifications have been put together and a completely heritage-friendly solution has been proposed to the client. From waterproofing aspect, the proposed solution was based on the Rinzaffo MGN Roman waterproofing mortar that can stop liquid moisture ingress while letting the walls to breathe. The product page explains the technical details how this is possible.

The same Rinzaffo MGN product has also been applied onto the floor, creating a waterproof yet breathable and completely dry hard floor.   

As the coal cellar had some large rusty metal beams to which plater won't adhere, we covered those beams with the Fondo Pozzolanico lime tanking slurry system. This stick to the metal, creating a base onto which lime plasters can be applied. Areas with strong water leaks have also been reinforced with this lime-based material.      

Once the waterproofing coat has dried, we applied a Cocciopesto plaster (lime mixed with brick dust) as second coat. This has excellent hygro-thermal properties, well-known since antiquity. In fact, cocciopesto plasters have been used in the Roman baths as it is moisture resistant, an excellent internal humidity regulator and also it is aesthetically very pleasing. 

Here is a photo gallery showing the whole process.

This solution completely transformed the previously very damp, neglected, unhealthy coal storage.

The plasters have been applied in October. Three months later, towards the end of January, throughout and extremely rainy and wet period the cellar stayed completely dry. The biggest subjective surprise was the related to the internal ambiance. All the smell was gone. The air was dry, healthy and the space felt normal and completely habitable. Pictures won't make justice here, but the subjective transformation was very significant.