Working with Sandstone

Tagged:
Stones

Sandstone is an excellent building stone that is easily worked. Often found naturally in nice blocks and slabs, this stone is also easily cut however the builder desires.

Sandstone is what the old-time builders called a freestone, which is a type of stone that splits readily in any direction, making it easy to work. Whereas many types of stone will shatter, or have distinct fracture lines that make precise cutting much more involved, these freestones can be cut quite simply wherever desired. The class is the optimal stone for novice masons, as it is easily dealt with. Schist is said to be another freestone, but be aware that our experience does not include schist, so we cannot guarantee it will work like sandstone does. Also be aware that there are some classes of sandstone that are very hard and crystalline, and they do not work quite as easily as the more conventional softer types.

Working the Sandstone

Sandstone is often found in nice slabs or blocks, making it rather easy to use even without trimming. However, the beauty of sandstone is how easily it is cut. When you cut it, whether with a stone hammer or a chisel, it is very predictable, and splits neatly along the line of the cut. Whereas other stones like limestone can require time and care to ensure a clean cut without shattering, sandstone can quite literally be cut anywhere the builder wants by simply using a conventional chisel and working the stone along the line of cut. Thus, angles, like for the skewbacks of an arch, are very easily made, and take very little time to do.

Arch Centering in Place — The skewbacks for this stone arch were cut of sandstone easily by a novice builder.

The Limitations of Sandstone

The sandstone in question must be vetted before use. Some sandstones are so soft that they literally turn into sludge if exposed to water and freeze-thaw cycles. Sandstone is generally soft and, obviously, tends to erode into sand over time. Thus, it is not the most durable of the building stones. However, it has been used extensively on many old structures, and is a good choice for smaller structures like stone culverts.

Painterhood Creek Overflow Culvert — A stone arch culvert built of sandstone.

One other consideration to keep in mind about sandstone is that it has a bit of a reputation for being more difficult to mortar than most other types of stone. Basically, the mortar is not as likely to bond to the sandstone as it would to other types of stone. This means that a little extra care in mixing and applying the mortar is necessary.