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Dry Mix Joint Compound

Dry mix joint compound is a product used in many areas of construction, from patching wall and ceiling material to filling seams in wallboard and drywall installations, to filling gaps between trim and walls or ceilings. Dry mix joint compound is more popular among professionals and do-it-yourselfers than ready-mix joint compound because it can be mixed as needed, with unused portions stored indefinitely in a dry state. It’s also a more economical choice, and weighs less than ready-mix compound, making it more desirable at job sites.

Dry mix joint compound and asbestos

As with many construction-related products manufactured prior to 1978, dry mix joint compound was typically mixed with asbestos fibers. In fact, considering the fibers’ insulative ability, high heat resistance, and high tensile strength and flexibility asbestos may have seemed like an ideal additive to the ubiquitous dry mix joint compound. At first glance, the addition of the fibers appeared to make dry mix joint compound a more effective, and even safer product, increasing its resistance to heat and corrosion. But as safety warnings concerning asbestos increased during the early 1970s, legislators revisited the practice of adding the fibers and in 1977, issued rulings that made it illegal to add asbestos to dry mix joint compound. Existing stocks of dry mix joint compound were exempt, and builders were allowed to continue to use those stocks until they ran out. As a result, today most buildings constructed prior to the early 1980s probably contain asbestos-embedded dry mix joint compound in walls, ceilings, and systems components.

Left undisturbed and in their pristine state, the asbestos fibers are not dangerous. But because they become brittle and degrade over time, any disruption, through renovation, remodeling, or even duct cleaning, can cause tiny particles of degraded asbestos fibers to become airborne, allowing them to be inhaled. Even something as simple as removing wallboard to add insulation – a common renovation that would seemingly improve the quality of your life by conserving heat and making your home cozier and more efficient – can instead prove highly dangerous. Once the fibers enter the airways and lungs, they can cause myriad health problems, including mesothelioma and other cancers. Anyone undertaking renovations in any building constructed prior to the mid-1980s should take precautions, by wearing a respirator or other suitable mask equipment.

Last modified: December 09 2009.