From studying cave art anthropologist have seen that the art of making interior walls goes back to the dawn of mankind when hides were used to line cave walls. This would have lessened the chill emanating from damp stonework and given a place to hang tools ad other items. Plaster was used to make wall linings in the stone dwellings of adobe natives and in the Biblical areas before the birth of Christ. Even the pyramids of Egypt boasted plaster for the interior chamber walls.
After the Industrial Revolution in the 1800's wood-framed walls were lined with small strips called laths and the surfaces were then plastered to form a smooth wall. This trade reached its zenith in the early 1900' s. Horsehair was often added for reinforcement which made the walls extremely hard and durable.
In the mid-1900's a new form of sheeting became the building standard. The United States Gypsum Company had invented the product in 1916, calling it “sheetrock,” but it failed to catch on as it was seen as inferior to plaster and lathe. Sheetrock was, and is, made from paper sandwiching an inner core of gypsum plaster. This plaster compound is mixed with fibers and compounds for mildew and fire resistance as well as waterproofing. The lamination of the paper and plaster makes a sheet strong enough to fasten to a ceiling.
Shortages of materials and labor during World War II led to the acceptance of sheetrock. The demand for cheap housing, quickly-built was alleviated with the ability to put up interior walls in 2 days instead of 2 weeks. The skill level to put up the sheetrock was minimal and labors also quickly learned to tape and fill the cracks with plaster.
Today drywall is the standard covering for interior walls although for a flawlessly-finished wall it takes a lot of skill from from the installers. To begin with the drywallers need plumb walls. This means that the walls must be straight otherwise over time gravity may cause the sheet to push through the screwheads.
The sheets are delivered to the site in 4 foot widths and lengths of 8, 10 and 12 feet, depending on the height of the room. There is one good side to the panels and so the sheets are shipped in pairs taped together with the good sides facing each other. This prevents scoring and damage to a face which will most likely be painted.
Sizing: The drywalling crews go in after the walls have been insulated and vapor sealed. Framing crews will build the wall frame with the center of each stud 16” apart. In this way if the drywall sheet is hug vertically it will cover exactly 3 spaces and be attached to 4 studs. In new home building there is often not to much cutting as the ceilings are usually the height of the drywall sheets or, even placed horizontally, there would be nothing taken off as 2 sheets would equal 8 feet, or the height of normally ceiling. For living rooms and hallways the drywallers will try to use longer pieces so there is not as much filling and taping.
Cutting: The sheets are cut by drawing knife across the paper surface with a long straight-edge, scoring the sheet, and then applying pressure. The sheet will snap along the cut line and, with the gypsum core broken, the paper back is cut along the break.
Hanging: The drywall sheets are usually hung with a 1 1/4” screw through the sheet and into the stud but a few crews still prefer nails. The fasteners are snugged just below the surface so they look countersunk. Special attachments for drills called “dimplers” are set so that each screw head goes in to certain depth and no further.
Filling the joints and screw heads with drywall compound finishes off the wall and prepares it for painting. Good tapers and “mudders” can transform the individual sheets and pieces into one long, unblemished wall. The tape is actually thick paper which is soaked in the drywall compound and covers the crack. Before the tape goes on drywall compound is worked into the cracks. A skim of mud goes over the tape and then the wall is left to dry for a day. Sometimes a light sanding is required but professionals do such a skilled job of taping that many put the finish coat on with out it. After this is left to dry then it is sanded and and the wall is ready for paint.
In some instances the entire walls will be plastered. This is called “veneer plastering” and the gypsum board used for this is called blueboard. This type of sheet is covered with a paper specially made to speed up the setting of the plaster coat. The result is a harder more uniform wall but this process requires a skilled hand.
Drywalling is an art which is easy to learn but difficult to perfect. When you put this in terms of time, the mess involved and perfection a trained, professional crew is the best choice.