Dust Control Drywall Compound: What to Know Before You Buy

Dust Control Joint Compound Basics

Drywall dust is as fine as talcum powder and it loves to travel. If there is even a tiny hole in the dust barrier, it is a sure thing that the drywall dust will find it and escape.

Once released, drywall dust, borne by HVAC cycles and by air currents, can even end up at the other end of the house on your bedroom dresser.

Drywall dust is so invasive that manufacturers of home vacuums often indicate that warranties are rendered invalid if the machines are used on drywall dust.

A number of methods have been designed to reduce drywall dust: airtight, negative-pressure plastic dust barriers; conventional sheet plastic barriers; wet-sanding methods; and sanding machines that attempt to suck away dust as you sand. While all make admirable efforts, none is a real match against drywall dust. One question remains: If drywall dust defenses are so inadequate, why not design a joint compound that produces no dust in the first place?

In general, dust control joint compound is a higher-priced specialty product that works fairly well at reducing the spread of dust, though it does not sand quite as smoothly as conventional joint compound.

What's Inside Dust Control Joint Compound

Dust control joint compound applies like regular joint compound, but its modified formula makes the dust heavier and causes it to clump as you sand it.

The clumps are heavy enough to drop to the floor rather than floating into the air like regular powdery drywall sanding dust. The secret is in the ingredients.

Regular joint compound contains over 35-percent limestone and less than 5-percent content each for attapulgite (an ingredient found in anti-diarrheal medications), mica, and talc.

By contrast, dust control joint compound raises the limestone content to closer to 50-percent, dispenses with the talc altogether and replaces it with an equal amount of perlite, and retains the attapulgite.

Does Dust Control Compound Really Hold Down Dust?

Conventional drywall dust is sometimes described as having a talc-like consistency. This description is spot-on since talc is exactly the material that floats throughout your house. Removing the talc solves much of the problem.

With dust control compound, the dust clumps are similar to coarse sawdust. If you have ever cut a piece of wood with a jigsaw, you have some idea of the aftermath of sanding a wall with dust control joint compound. The bulk of the dust piles up at the base of the wall. Then, there is a layer of fine dust radiating out another couple of feet.

Outside of that is a very fine layer of dust extending just a few feet from the wall, with very little dust beyond that area. Compared to the dust from regular joint compound, this is a noteworthy difference.

Quality of Dust Control Compound Finish

One advantage of standard drywall joint compound is its smooth finish. With good-quality joint compound, you can successively step down your sandpaper grits. By the time you have reached the finest grit, the sanded compound is hard and glass-smooth.

With dust control joint compound, the best finish is medium-hard and somewhat rougher, a degree short of glass-smooth. So, you will not want to use a dust control joint compound for the final skim coat of a level 5 drywall finish.

Due to the clumping effect that prevents the material from breaking up readily into fine particles, dust control compound is slightly more difficult to sand than standard joint compound. 

Tips for Using Dust Control Drywall Compound

Create Dust Barriers

Using dust control joint compound does not mean you can sand drywall with abandon and leave the work area open to the rest of the house. You will still need to erect dust barriers if you want to keep the room or surrounding area dust-free. If you do use a barrier, the dust control joint compound will be far less prone to escaping through small holes and seams in the barrier and traveling from one end of the house to the other.

Use on Smaller Areas

Dust control joint compound tends to cost two to three times more than conventional joint compound. Due to its higher cost, this type of joint compound may not be cost-effective for large areas. Instead, you may wish to confine your use of the dust-control joint compound to smaller areas that are in or near dust-sensitive areas.

Clean With a Broom

With conventional joint compound, every sweep of the broom only creates more dust. This is why it is best to suck up the dust with a shop vacuum fitted with a drywall dust-compliant bag. But with dust control joint compound, it is possible to sweep up most of the pile without creating dust clouds.