Natural stone flooring lends a touch of class to formal entryways or a rustic look to an outdoor bathhouse. No matter where you choose to install it, there is a type of stone flooring to fit your style. From solid marble tiles to rough-cut limestone slabs, stone floors provide durable beauty.

1. Start with the surface that will be under your floor. On new construction, a subfloor of concrete may be poured, providing a level surface. On a remodeled floor, the installation of a water-resistant backer board is necessary.

2. Figure out the total amount of stone tiles you will need by measuring the length and width of the floor and adding 15 percent more to allow for cutting and fitting pieces around the edges.

3. Purchase mortar or grout made specifically for the stone flooring you choose. Speak with the customer service person in the tile department when buying. Because different stones retain moisture at various rates and because the surfaces vary from rough with holes to glass smooth, it is very important to choose the correct mortar.

4. Begin laying square tiles in the middle of your room and working outwards. Use straight chalk lines on the subfloor as guides. However, if you are remodeling a floor and the walls are not perfectly straight, consider which part of your floor needs a straight edge and begin tiling there. Keep in mind that the last tiles will be uneven so plan to install them in a place not frequently seen.

5. Lay rough-cut, natural shaped flooring stones by placing each one next to the prior one and fitting smaller stones in-between. The idea here is to place the larger flagstones first for an ordered look and use the smaller ones in a consistent manner. Use a hammer and chisel to break off smaller stones for filling.

6. Seal your natural stone floor if it has a porous surface. Buffed marble and granite need no sealant but flagstone and other porous surfaces require the application of a sealant. Because tiny holes exist in natural stone, they can absorb stains, making it difficult to clean. Sealant provides a clear water-resistant protection that repels stains.