Drywall, also known as plasterboard, wallboard, or sheetrock, is a panel made of gypsum plaster and pressed between two thick sheets of paper. It is used for interior walls and ceilings and is usually supplied in 4×8 and 4×12 sheets. The plaster used to make drywall is a building material used for coating walls and ceilings. It starts as a dry powder that is similar to mortar or cement. Mixed with water, the powder forms a paste which then liberates heat and hardens.
Standard drywall is a pale gray or ivory on one side and a darker gray or brown color on the other side. The lighter surface is the side that faces into the room. The opposite side will have manufacturers’ logos and visible seams down the edge.
There are also other types of drywall that you can select from depending on the type of environment it will be installed in. Three of those types include:
- Moisture & Mildew Resistant – For walls in rooms with high moisture, like bathrooms and kitchens, it is better to use a moisture resistant drywall. When this type of drywall is made, it is also impregnated with waterproofing materials. It is breathable so the surface beneath the board can “breathe” through the surface of the wall.
- Foil-backed – This type of drywall has vapor-resistant paper on one side so it is less protected than moisture-resistent sheets. It has a silver foil-like layer on the nondecorative side. This type of drywall is used in cold climates but not for moisture resistant materials or humid climates.
- Fire-resistant – This drywall has greater fireproofing qualities than standard drywall. The best use for this type is with integral garage ceilings, stairwells and some corridors.
The drywall is attached to the walls with drywall screws and drywall glue. Once the drywall is hung throughout the house, there is additional work done to prepare it for primer and paint. Seams and nail holes need to be smoothed out. This is a labor intensive process and the time it takes depends on the number of seams and the overall size of the project. The finished project will create the illusion that the wall consists of one flat piece instead of several 4×8 or custom cut boards.
Where two pieces of drywall meet, drywall tape is applied. Any seam and especially the corners need to be taped. Then, drywall compound, or mud, is applied to add a seal to all joints. You also want to make sure that all of the screws or nails are firmly embedded into the drywall sheets and add drywall mud over those as well. Once the layer of drywall compound is dry, it must be sanded. Two additional layers of mud are applied and each layer sanded.
The sanding should create a seamless, smooth finish. Most drywall finishers follow the “6 foot finish rule.” This means that if you stand 6’ away from a wall, you can not see any seams, bumps, bubbles, nails, screws or imperfections.
At this point, the wall is perfectly smooth and ready for primer and paint.