Gypsum decontamination, paneling, drywall or drywall panels and joint compound
Today, drywall and modern joint sealants do not contain asbestos. However, this has not always been the case.
Use of asbestos in construction materials and gypsum decontamination
In the case of a drywall system, the references to asbestos focus mainly on the asbestos that was in the joint compound or in some paints or spray products that would have been applied to the drywall ceiling.
It is important to remember that the asbestos-containing joint compound may have been applied not only over drywall joints up to 18 “in width, but also in repairs, around penetrations or fixtures and in some buildings as a thin layer over an entire surface of the ceiling or wall.
Drywall systems likely to contain asbestos, at least in finishes, sealing joint compounds, topcoats or systems installed on gypsum, date back to around 1910 until the early 1980s in North America (1982 in Canada).
Asbestos content
In the joint compound, the asbestos content varied, but was generally between 3 and 6%. Even if the gypsum boards themselves did not contain asbestos, this means that by weight the asbestos content of the wall system was around 0.25%.
Be wary of the fact that even if the asbestos content of plasterboards (uncommon) or joints (common) can be relatively low, it is possible that certain treatments based on aerosol putty or textured ceilings are very rich in asbestos , which can reach 40% or even more.
How to cover or remove drywall or gaskets containing asbestos
It is important not to touch drywall materials suspected of containing asbestos; it is generally safer to leave these materials intact or cover them. If demolition or removal is necessary, the additional steps described in this document are important.
Testing drywall containing asbestos
If, in an older building (built before 1980 in North America), you are not sure whether the drywall, gypsum board or joint compounds used in your building contain asbestos, you should do analyze representative samples of the two materials (usually without asbestos), the compound of the joints and the plasterboard (which often contains the largest amount of asbestos) in an approved laboratory for asbestos analysis.
Remember that even without asbestos, dust from joint compound and gypsum board creates ultrafine particles that can be a serious respiratory hazard.
Do not attempt to remove a gypsum board yourself if it contains asbestos
Since the dust from the plasterboard panels and the dust from the joint compound are easily airborne and brittle (by sanding, cutting, sawing or other demolition operations), it is advisable not to start asbestos removal yourself. plasterboard walls, the same for cleaning.
However, if you live in an area where removal or repair of asbestos-containing drywall is permitted and you intend to do it yourself, take appropriate measures to control the dust and protect yourself properly, such as using full wetting and a wet sweep to clean the house and wiping the wet floor for work.
Turn off and protect all air handling devices (air conditioners, heaters, humidifiers, dehumidifiers, fans) before handling materials containing asbestos. Do not use a standard vacuum cleaner because it will activate the ventilation of asbestos particles. Some HEPA approved vacuum cleaners may also not treat asbestos and thereby increase airborne asbestos levels.
Typical procedure for removing gypsum board in the case of small jobs
“Little work” should be limited to touching or removing less than one square meter of drywall when a joint compound containing asbestos has been used. The use of a respirator fitted with new or used P100 filter cartridges and a disposable coverall is optional for small removal jobs. Then do the following:
- Install a sheet of polyethylene under the work area using duct tape.
- Spray the drywall to be removed, focusing on the corners and places where joints are visible or presumed to be present.
- Continue spraying any suspicious material as the work progresses.
- Dispose of all waste as ordinary construction debris (disposal of asbestos waste may be necessary depending on where you live).
- Prepare a modified water solution by adding a cup of dishwasher detergent to 20 liters of water. This wetting agent will serve to reduce the surface tension of the water, thereby improving its wetting and penetration properties.
Typical procedure for removing and demolishing gypsum board in the case of larger work
For larger jobs, do the following:
- Shut down the HVAC system that affects the work area. Cover all HVAC vents and diffusers.
- Wear a manufacturer approved respirator (with new or used P100 filter cartridges) and a disposable coverall.
- Spray the drywall to be removed, focusing on the corners and places where joints are visible or suspected to be present.
- Continue spraying any suspicious material as the work progresses.
- Control the dust in the area by spraying the fallen debris.
- Dispose of all waste as ordinary construction debris (disposal of asbestos waste is mandatory or not, depending on where you live and applicable regulations.
Note: special waste disposal or air monitoring may be required for this type of work, or a duly authorized asbestos work permit is required, depending on where you live and the standards in effect. It is important to do business with professionals for gypsum decontamination contact us for more information.
