The interior of a columbarium is made out of many different materials depending on the company. There are concrete, granite, metal and polymers. At Kyber we use metal interiors because of their strength, design flexibility and their ability to handle all conditions mother nature can throw at them.
The exterior of a columbarium can also be made of many different products. Granite would be used the most extensively with other types of stone such as limestone and masonry becoming more popular.