Choosing Sheetrock Thickness

Modern sheetrock products provide a quick, easy and economical way to produce a uniform finish on a masonry wall, stud-partition or ceiling before decorating it. Sheetrock is available in various types and sizes; and choosing and buying an appropriate sheetrock thickness for the job at hand is essential.

Compared to the practice required to perfect ‘wet’ a plastering technique, any reasonably experienced DIY home enthusiast can work with sheetrock, also known as drywall, to attain a surface good enough for decorating.

Main Types of Sheetrock and Their Thicknesses

Although sheetrock can be bought already cut to several different panel sizes the most common size for a sheetrock panel is 8 feet by 4 feet, which available, regardless of the panel size, in thicknesses of 3/8 inch, 1/2 inch and 5/8 inch.

The main types of sheetrock are:


Ideal for walls in rooms that do not currently retain heat very well, they’re guaranteed not to warp due to temperature and humidity variations. They have a high strength ‘polyfoam’, or similar, core meaning they’re still easy to cut with a knife or saw. Their typical thickness is ½ inch.

Fire retardant

Panels of this sheetrock are fire resistant and non-combustible. Check with your local building regulations as you may well have to fit this sheetrock on walls with an exposed external face or on staircases. Fire retardant sheetrock will have something like “Fire Resistant” printed on it and will probably have a grayish backing to it. Fire retardant sheetrock is, understandably, the most expensive and invariably comes in 5/8 inch thick panels; cutting it is best done with a fine toothed saw.

Water resistant

Sheetrock can be used in any rooms likely to have high humidity, or even become wet, such as bathrooms and kitchens. You should be able to quickly identify water resistant sheetrock as, in its 4×8 panels; it should have a green backing. Guaranteed not to warp or rot it can retain its strength even when wet – the 1/2 inch version will be perfectly OK to use.

Wallboard or Baseboard

A high quality sheetrock that is primarily designed to be used on ceilings. However, it can also be used for wall linings and in stud-work partitions. Easily recognized by its ivory paper face it is available in 3/8 inch and 1/2 inch thickness. If you’re installing this on a ceiling – use the 3/8inch sheetrock.

Other Types of Sheetrock

Dependant on the jointing technique you want to use, sheetrock can be bought with two types of edging:

Square Edge – is usually only available as 1/2 inch thick sheetrock and most commonly used on walls.

Tapered Edge – available in a 3/8 inch thickness and often used on ceilings; it is also available in a 1/2 inch version for use on walls.

Whilst the 4×8 foot panels of sheetrock are the ones most commonly used, you can buy pieces as small as 2×2 foot and only 1/4 inch thick. However, these smaller panels are usually only used for repairing holes in sheetrock ceilings. Having taken note regarding any fire regulations or damp/humidity issues in the building; generally speaking fit 3/8 inch panels to a ceiling or on top of existing plaster work and 1/2 thick sheetrock on to stud-work.