Joint Compound vs. Spackle: What’s the Difference?

Half of the battle with common home repairs is picking the correct product to use. And when two products have some overlap in their intended purpose—as spackle and joint compound do—the choice can get even trickier.

Is joint compound the same as spackle? Both popular putties are used in wall and ceiling repair and construction, and they look almost identical to the untrained eye. The similarities end there, however, as they have various formulations that affect factors like dry time, shrinkage, and project scope. If you’re about to tackle wall installation or repair, read on for the 411 on joint compound vs. spackle to handle the job like a pro.

Spackle is generally intended for repairing minor damage to drywall or plaster.

Spackle, made of gypsum powder and binders, has a gooey paste-like consistency and is sold pre-mixed in tubs. When making minor repairs to plaster or sheetrock, spackle is the way to go. It’s used to fill small dings and dents, like nail holes, in walls. Spackle dries more quickly with less shrinkage than joint compound—and that fast dry time (usually about 30 minutes) means you can sand and paint over the filled flaws almost right away.

Joint compound is most often used when hanging new drywall.

Joint compound (also known as “drywall mud” or simply “mud”) is comprised mainly of gypsum dust and can be bought in pre-mixed tubs, like spackle. A major difference between spackle and joint compound is the latter’s frosting-like consistency, whereas spackle is thicker.

During drywall installation, contractors affix large sheets of gypsum board to a wall’s framing, apply drywall tape to the boards’ seams, and then cover the tape with joint compound. With a little bit of finish work, the joint compound helps create a smooth surface with undetectable seams. Spackle isn’t suited for this purpose because its quick-drying nature gives you less working time, which makes determining when to use spackle vs. joint compound relatively straightforward.

Different types of joint compound and spackle are suited to different jobs.

Types of drywall mud include all-purpose joint compound designed for easy application to drywall seams, quick-setting joint compound that’s better suited to patching jobs because it dries more quickly, and taping and topping joint compounds, which are applied in sequence over drywall tape.

Spackle varieties, meanwhile, include lightweight spackle (made with a vinyl binding agent) suitable for small repairs and an all-purpose formulation (made with acrylic) ideal for holes up to ½ to ¾ inch in diameter. Both types of spackle are elastic, minimizing shrinkage.

Joint compound can be substituted for spackle if need be, but not vice versa.

Got a tub of joint compound left over from a previous renovation? Feel free to substitute drywall mud for spackle for small drywall repairs. Just be aware that joint compound runs the risk of shrinking, which calls for multiple coats and a longer dry time—sometimes up to 24 hours.

On the other hand, if you’re all out of joint compound but have what looks like enough spackle to patch a large hole or finish your drywall installation, hold off. You’re better off going back to the hardware store for more drywall mud instead. Spackle (especially the lightweight variety) dries too quickly for the kind of coverage needed to make big repairs or install drywall—jobs which definitely call for joint compound.

Both products can dry out quickly during use as they’re exposed to air.

It’s important to work quickly with both joint compound and spackle, and you should keep either product covered when not in use. If you’re mixing up your own DIY spackle or joint compound with water and a powder mix, only make as much needed for the job at hand.

Patching small holes with either product is a similar process, with a few exceptions.

For holes in drywall or plaster that are smaller than a half-inch, opt for a premixed spackle and follow these steps:

• Prep the area by removing loose drywall around the hole’s perimeter.
• Apply spackle with a putty knife. Angle the knife about 45 degrees and run it in downward motions until the hole is filled.
• Remove excess spackle with the putty knife.
• Let the spackle dry according to the manufacturer’s instructions; apply another coat if necessary.
• Smooth the surface with sandpaper when completely dry, and wipe away any remaining dust.

A similar technique applies for medium-sized holes or cracks in drywall or plaster measuring several inches, but opt for joint compound and reinforcing mesh—a backing material typically made of aluminum that, once adhered to damaged drywall or plaster, gives the joint compound something to bind to. The mesh helps ensure that the repair won’t dry and crumble over time. Apply mesh tape or a patch to the prepped surface, covering the hole completely. Then apply the joint compound, letting it dry completely according to the manufacturer’s instructions, before sanding and finishing.

If you have a very large drywall hole, you may need to patch it with a piece of drywall, some joint compound and a reinforcing scrap of lumber.