Drywall 101

Drywall T-Square

A drywall t-square is essential for cutting and installing drywall panels. It is used primarily to provide a strait-edge along which to cut drywall using a drywall utility knife. Below are a few tips to look for when buying a drywall t-square.

Drywall t-squares are basically two pieces of metal connected at right angles to one another. The shape of the two pieces of metal creates a capital T-shape, thus the name. The two pieces of metal create a 90° angle just below the cross bar of the T-shape. This 90° angle is essential to ensure that the cut edge (butt joint) is exactly 90° from the bound edge (drywall seam) when cutting drywall panels.

T-squares are generally made out of aluminum. Aluminum is preferred because of the light weight and resistance to rusting. Since most drywall panels are 48 inches tall, standard size t-squares are 48 inches from top to bottom, though other lengths can be found. 54 inch drywall sheets are sometimes used when hanging drywall in rooms with tall ceilings. This extra 6 inches prevents unnecessary seams if the ceiling is higher than 8 feet and less than 9 feet. When using 54 inch panels, a 48 inch t-square falls short so longer t-squares can be used however these longer t-squares are useless for cutting standard 4 foot sheets.

There are a few features to look for when buying a drywall t-square. The long edge of some t-squares are made with one-eighth or more inch thick aluminum. This thicker metal creates a safer straight edge than thinner models of just one-sixteenth of an inch thick metal. A thicker straight edge is safer because it prevents the utility knife from slipping off the cutting side of the t-square and sliding across the metal face of the t-square.

48" tall adjustable drywall T-square

Another feature to look for is an adjustable height. As just mentioned, most t-squares are 48 inches tall to match drywall panels. Some have an adjustable screw where the two pieces of metal come together. This allows the crossbar of the t-square to slide vertically along the long edge and create a shorter t-square. For example if you have an already ripped panel 30 inches in width, a 48 inch t-square is difficult to use. An adjustable t-square can quickly be short end for this one cut and then returned to full height for other panels. Ideally, you would like a 54 inch tall adjustable t-square that can be used for cutting all sizes of drywall panels.

A drywall t-square is primarily used to cut full sheets of drywall at right angles. However, a professional drywall hanger can use it in a few other useful ways. At times angle cuts are required to match vaulted ceilings or other architectural designs. The 90° angle of a t-square can be used as a reference on the wall against which to determine the proper angle cut. A drywall hangers ability to use this tool and calculate the intricate angles needed speak to his ability as a carpenter, including his math skills.

Drywall t-squares are an essential tool for a drywall hanger. When buying a t-square look for one made of thicker metal and adjustable height.