Stairs can be made from one timber or a combination of many. Below is a list of the timbers most commonly used to manufacture stairs from. It’s also worth noting MDF and Plywood are frequently used for the treads and risers to keep costs down when the stairs are to be carpeted.
Pine
Pine is the most common timber used to manufacture staircases. It is a straight-grain wood that is highly resistant to static bending and fairly resistant to compression.
It is popular due to being the most inexpensive material suitable for staircase manufacture, it is also easy to work with, ideal for painting, however, it can also be stained, varnished or waxed.
Hemlock
Hemlock is not resinous, and the colour is virtually uniform with occasional darker purple-red stripes. It has a straight grain pattern, very suitable for varnished and etched finishes. It features medium resistance to static bending and compression.
Western hemlock is an evergreen tree from North America. It grows prolifically from the coastline of northern Sonoma County, California, north to the Kenai Peninsula, Alaska and east to Idaho and Montana, and is widely harvested in these regions.
White Oak
Oak is a hardwood, has few knots, and gives a premium finish, ideal for waxing or varnishing. Rated as very durable; frequently used in boatbuilding and tight cooperage applications. Has a tell-tale smell that is common to most oaks. Most find it appealing. Usually more expensive than Pine and Hemlock, prices are moderate for a domestic hardwood, though thicker planks or longer boards are more expensive. Staining or varnishing Oak you can create amazing results.
White Oak is strong, beautiful, rot-resistant, easy-to-work, and economical, representing an exceptional value to woodworkers. It’s no wonder that the wood is so widely used in cabinet and furniture making.
Sapele
Sapele is a dark hardwood with a red tint to it, similar in appearance to Mahogony, it is generally used where a darker coloured timber is required. Fine uniform texture and good natural luster. Sapele has a distinct, cedar-like scent while being worked.
American Walnut
American Walnut is a popular hardwood timber which is dark in appearance, it can be used for manufacturing stairs but not generally straight flights as longer lengths are hard to acquire. If fits nicely like treads combination with white risers. Strong and durable and more expensive wood. Gives style and individuality to your staircase.
Other tree species are also available. Ask for options.
Plywood
Plywood is a material manufactured from thin layers or “plies” of wood veneers that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. All plywoods bind resin and wood fibre sheets (cellulose cells are long, strong and thin) to form a composite material. This alternation of the grain is called cross-graining and has several important benefits: it reduces the tendency of wood to split; it reduces expansion and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across all directions. There is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Mostly used are 9mm and 12mm for staircase risers.
MDF
Medium-density fibreboard (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibres, often in a defibrator, combining it with wax and a resin binder, and forming it into panels by applying high temperature and pressure. MDF is generally more dense than plywood. It is made up of separated fibres, but can be used as a building material similar in application to plywood. MDF does not contain knots or rings, making it more uniform than natural woods during cutting and in service. Typical MDF has a hard, flat, smooth surface. MDF may be glued, doweled or laminated.
MDF is usable for staircase treads because of its strong surface. Available thickness 22mm, 25mm, and 30mm.
Thinner than 12mm MDF is not recommended for risers due to its weakness.
Advantages:
- Consistent in strength and size
- Shapes well
- Stable dimensions (less expansion and contraction than natural wood)
- Takes paint well
- Takes wood glue well
Disadvantages:
- Low grade MDF may swell and break when saturated with water
- May warp or expand in humid environments if not sealed
- Dulls blades more quickly than many woods.
- Though it does not have a grain in the plane of the board, it does have one into the board. Screwing into the edge of a board will generally cause it to split in a fashion similar to delaminating