Why is celloluse the cheif ingredient to drywall? What is the purpose of drywall? Is it just to look good?

Question

is drywall and sheetrock synonymous?

Answer 1

Cellulose is a minor ingredient in drywall. It is only the paper that covers the outside. The primary component of drywall is gypsum, which is Calcium Sulphate Hydrate. This gypsum is mined from the earth in open pit mines or underground mines and formed into the sheets of drywall.

The primary advantage of drywall over some wall-coverings is that it is inorganic, so the gypsum does not burn, will not conduct electricity, and when propertly treated is not readily damaged by moisture. Special types of drywall are used for bathrooms or other areas that experience moisture. Drywall has some fire-retardant properties as well, and when drywall is exposed to a fire it is endothermic,absorbing heat and giving off moisture (the gypsum chemically changes to anhydrite) and thus delaying heat transfer. In an ideal installation it can have a 2 hour fire rating.
http://www.awc.org/Publications/dca/dca3/

The other advantage to drywall is that it is very inexpensive compared to most other building material, can be installed quickly, is easy and quick to paint, and is easy to repair and replace when damaged. Drywall has mostly replaced plaster and other more labor intensive wall coverings.

Sheetrock (TM) is the trademark of US Gypsum.
http://www.usg.com/navigate.do?resource=/USG_Marketing_Content/usg.com/web_files/products/brand_overview/Sheetrock_Brand-BO.htm

Here is a gypsum mine with mine photos and lots of information about gypsum:
http://www.alliedcustomgypsum.com/ACGgypsum.htm

Answer 2

I thought the chief ingredient of drywall was some kind of chalk.. oh well.. ok..

drywall and sheetrock are the same (I think)

the purpose.. is to provide some type of finish that is cheap to build with yet easy to use like wood... it is not as flammable as wood so it is safer.

it is also easier to repair than wood if something happens to it.

it is a bit of a fire barrier... which is why garages need thicker sheetrock than other rooms...

Answer 3

celluose is just the outside veneer. However, to correct you, dry wall is mainly composed of gypsum (a common white mineral) and a bonding agent. Drywall is a pre primed building material designed to replace plaster for the use on interior walls and ceilings. It has limited fireresistance, and the celluose (mainly paper) veneer is to help paint bind to the surface like a primer. The celluose helps to smooth out the gypsum surface too.

Sheetrock is technically different in some cases. Known as a concrete backerboard in some places. However, the term is used interchangably.

Sheetrock is made from a asphalt/concrete/brown gypsum blend...mainly used for shower walls, subflooring and walls for tiling surface. Unlike drywall, it's specifically designed to hold mortar and tiles. It lacks a celluose veneer and it remains porous to let the mortar grab the surface. It's okay for humid surfaces but not direct water contact. It's more brittle than drywall. It needs to be screwed on to plywood for floor applications.

Answer 4

Additional info - My understanding is that drywall was made as a replacement for plastering. Old houses had plastered walls. These were extremely labor intensive, required highly skilled workers and were very expensive. By comparison, drywall is easier and quicker.

Answer 5

Sheetrock is the company that produces drywall. drywall is made with a gypsum and its fireproof. it stops fire from burning the frame of the whole house.

Answer 6

The above poster is sort of correct. Cellulose is an insulator as well as a moisture blocking material, thus no seepage.

The other guy was looking for FRP, which is flame retardant plastic.

Answer 7

Dry wall doesn't burn It is meant to slow the fire down if your house ever started on fire.