Hi Mark, to install TandoStone siding over a concrete wall, there's three options:
1. The most common procedure is to "fur out" the area by using furring strips which are thin pieces of wood fastened to the wall as a nail surface for the siding.
2. You can penetrate the concrete itself (at least 1/2") with the proper fastener and drill.
3. You can put up a new surface over the concrete, such as plywood. This option is costly and thus less common.
For additional information, see Tando's [special cases installation guide](https://cdn2.hubspot.net/hubfs/1806455/DIV5357A_Installation%20Guide%20over%20Masonry-Stucco-CMU_Biling.pdf).