Joint compound and spackle are two essential materials that are used when working with drywall. Both products are white, thick, and have a paste-like consistency. So, what’s the difference between them? Spackle and joint compound are often used interchangeably, and they do perform similar functions—and they're even often used together on drywall projects. However, each is designed for different, specific purposes.
Contains gypsum and limestone
Use in large scale wall projects
Sold in larger quantities
High shrinkage when dry
Harder to smooth out
Contains gypsum and binding agents
Designed for small wall repairs
Sold in smaller quantities
Low shrinkage when dry
Easy to use
What is Joint Compound?
Joint compound is also known as drywall mud or just mud. It’s comprised mainly of gypsum and limestone, but it also has other materials such as clay, mica, perlite, and starch. Joint compound has a spreadable consistency similar to mud, which is how it got its common name. However, the consistency depends on the specific type of joint compound. In general, it's used for heavy wall repairing projects or for new drywall installation. Joint compound can also be used to fix small holes or smooth out divots in walls.
Uses and Cost
The primary use for joint compound is to seam and smooth new drywall installations. It’s sold premixed in 1-quart to 5-gallon containers or in a powdered form you can mix yourself with water. Although it can be used for smaller projects, it is sold in large containers and designed to cover a large area. It also takes joint compound some time to dry—up to 24 hours before it’s sandable or paintable. There are four types of joint compound:
- All-purpose: used for all phases of the patching process.
- Topping: used for final coat and typically spread onto a wall with two dried coats of taping compound.
- Taping: goes over drywall tape and sets the seam between the drywall.
- Quick-setting: dries faster than the other compounds and works well for patching deep cracks and wide holes.
Joint compound is relatively inexpensive. Although it doesn’t cost a lot up front, it doesn’t make sense to purchase a large container of the substance for minor repair projects. Also, some homeowners may find it hard to get a smooth finish when using joint compound because of its consistency, and it does take some practice and patience to get a seamless finish.
What is Spackle?
Spackle compound for drywall is comprised of gypsum powder and binders. It is thicker than joint compound, similar to the consistency of toothpaste. Spackle is sold in a premixed tub container. It is also available in several different grades designed for specific applications. Spackle is used to fill in dings and dents, nail holes, or any small damaged areas on walls. It dries faster than joint compound, typically within half an hour. However, there are several types of spackling compounds available, and it's not all designed just for drywall.
- Lightweight spackling compound contains fine aggregate with sodium silicate and an adhesive. It is designed for repairing smaller dings, holes, and cracks. It doesn't sand well and is only meant for quick, small fixes.
- Standard/All-purpose spackling compound is gypsum-based (similar to joint compound) and designed for repairing larger holes, gouges and cracks in drywall.
- Vinyl spackling compound is designed to fill in holes and cracks up to ¾-inch deep. It's applied in layers, with each layer allowed to dry in between. Because it contains vinyl, this type of spackling will not dry out or crumble, and it sands well.
- Acrylic spackling compound, like vinyl, is flexible and can be applied to drywall, stone, brick, wood, or plaster.
- Epoxy spackling compound is an oil-based filler that's used to repair holes, gouges, cracks, or other imperfections in wood.
Uses and Cost
Spackle is made for small repair jobs on drywall. It’s thicker than joint compound and harder to spread. Because it has a binding agent mixed in with the gypsum powder, it is more elastic and less likely to crack or shrink when dried. Spackle is a little more expensive than joint compound. However, it’s not an apples-to-apples comparison. Joint compound is used in large quantities to cover a larger surface area, so you end up spending more on it for your drywall project. Spackle may come in a small container, but you only use mere ounces of it at a time, and a tub can last for months, if not years.
Which You Should Choose
Both joint compound and spackle have their various uses in the home, and choosing the right one for the job makes all the difference. Most homeowners may only need to use spackle for small repair jobs around the house. Keeping both joint compound and spackle in your knowledge toolbox is a good idea, though, so you will be prepared for any drywall job that comes up.