Drywall is widely used for building homes in North America particularly in the United States and Canada. It’s widely available and quicker to install than other traditional options like plaster. You may also read about drywall referred to as gypsum, plasterboard or wallboard among other names.
While regular drywall can be used in most parts of a home’s walls, the bathroom area is one that is better suited to a special type of drywall called greenboard which is moisture-resistant or PURPLE drywall which is resistant to moisture, mold and mildew.
While green drywall can be purchased from different manufacturers, PURPLE drywall is a brand name from Gold Bond Building Products, LLC.
Why does special drywall need to be used in bathrooms?
Drywall is made from gypsum and surrounded with a special layer of paper over top. It’s typically 1/2″ thick but can also be found in other thicknesses depending on the use. Due to its make up, drywall is susceptible to moisture and water and thus mold and mildew.
Accordingly, regular drywall is not suggested in places where high levels of moisture are found which is typically in the bathroom.
Drywall is widely used in American and Canadian homes for a number of reasons. You can apply a number of materials over top of drywall including paint, wallpaper and tiles among others so it’s very versatile. It tends to be relatively easy and quick to install too.
But in order to install drywall in a bathroom where water and steam will be common, it’s best to use a special type of drywall which is commonly green or purple in color to distinguish it from regular drywall.
What is special about green and purple drywall?
Drywall is normally white or light gray on one side and a darker gray or brown on the other. The white (lighter) side is the one that is installed facing into the room you’re finishing.
In order to easily distinguish from regular drywall, two products suitable for use in the bathroom are distinctly colored and widely available for use:
Green drywall
Green drywall was designed to resist moisture and should be used in conjunction with moisture and/or mold-resistant mud. Before the introduction of mold-resistant drywall, it was a better choice for a bathroom than regular drywall.
While more expensive than standard drywall, it’s less expensive than mold-resistant drywall.
But now that mold-resistant purple drywall exists, you’re better off using green drywall in areas where water is minimal at best but where moisture could be present such as the basement, kitchen and laundry room.
PURPLE drywall
PURPLE brand drywall is manufactured by National Gypsum under their Gold Bond Building Products brand name. Purple drywall was designed to be moisture, mold and mildew resistance so its ideal for bathrooms.
PURPLE drywall products are offered in several different versions which each offer potential benefits over regular drywall including soundproofing, scuff-resistance and impact resistance.
As such it’s a better option than green drywall in rooms that will experience direct contact with water and moisture exposure such as a bathroom and shower area.
Purple drywall tends to be the most expensive option available given its design and benefits. According to the manufacturer
, it would cost less than $1,000 to upgrade your drywall to the PURPLE brand where recommended in a 2,500 sq. ft house.
So in that regard, it is more expensive but in the bigger picture, it’s a relatively small charge compared to the entire cost of the house and certainly when compared to the cost of mold remediation if you go with cheaper standard drywall.
What about blue drywall?
Blue drywall is also something you may also come across. Blue drywall is also water and mold resistant which makes it a better choice than regular drywall but it was designed to be used with veneer plaster. Blue drywall however can’t be use with mud, tape or paint.
If you’re drywalling in an area that will receive direct water exposure such as a shower area, PURPLE drywall is still your best bet.
What happens if you use regular drywall in a bathroom?
Regular drywall is more susceptible to water, mold, mildew and moisture in general than bathroom-specific green or PURPLE drywall.
When drywall regularly gets wet or is exposed to moisture, it can structurally weaken over time. This can also lead to the aforementioned problems of mold and mildew.
The last thing you want to do is complete a costly refinishing of your bathroom and have to rip out a wall(s) several years later to replace drywall that should have been properly finished with water, mold and mildew-resistant drywall in the first place.
How to deal with wet drywall in a bathroom
What happens if your bathroom drywall is exposed to water due to a floor or leak?
Here are steps to take to address wet drywall in your bathroom after you’ve determined and addressed the source of the water damage:
- Determine the extent of your water damage with a visual inspection and then use a water moisture meter. A normal moisture reading for drywall is between 0.2% and 1%. Consult a professional if the damage is severe enough.
- Look for evidence of mold or mildew that will need to be addressed, perhaps by a professional if needed.
- Seal the room and use a professional-grade dehumidifier to dry out the room and walls.
- Check the wall again for moisture to see the improvement. Look again for evidence of mold or mildew.
- Assuming you can get a low enough moisture reading and have no evidence of mold, mildew or rotten drywall, you can repaint the drywall with alcohol or oil-based primer followed by bathroom-suitable paint.
What benefits does drywall offer over other materials like plaster or concrete in your bathroom?
Advantages of building with drywall in the bathroom includes the following:
- Drywall is quicker to install than plaster.
- Drywall results in a smooth surface since you’re installing a prefabricated product that is completely flat by design.
- It’s a material that is more fireproof than wood.
- Drywall is relatively cost effective and due to its popularity is easy to find.
- You can easily repair drywall if you dent it or need to patch holes from nails or screws.
- If you decide to remodel your bathroom in the future, it’s much easier to do than with materials like concrete up to and including removing the drywall completely.
What downsides does drywall have in your bathroom?
While drywall has a number of upsides, there are some potential downsides that one should be aware of when using it in the bathroom:
- Drywall does not respond well to water or moisture and might need to be completely replaced after a flood or water leak.
- Once damp, mold can grow on drywall which can become a health hazard in addition to the visual eyesore it can produce.
- Termites are attracted to the paper surface of drywall and thus can be an expensive problem for homeowners if you experience an infestation.
- Cheap drywall particularly from China flooded the market in the mid 2000s that is believed to have caused health problems and resulted in expensive replacements and costly lawsuits. The exact source of this drywall can sometimes be difficult to trace although this has improved since this debacle occurred.
Why is drywall used in North American homes so frequently?
While drywall is a common building material in some parts of Europe like the UK, you tend to find homes built with concrete in countries like Germany. While bathroom remodeling is a thing in Europe too, building with concrete means you’re less likely to completely gut a bathroom given the constraints.
Home-flipping isn’t a thing in many European countries like it is in America and Canada. People tend to buy a home and keep it for decades or longer. In North America, home renovations are thus more common since people can flip homes that have been remodeled and modernized, something that is much easier to do with drywall.
A drywall-built home can have entire rooms opened up by knocking out a wall or two. A concrete-built home? Not so much.
In North America, wood-framed homes are relatively easy to find given the prevalence of softwood lumber in Canada and the United States. Wood-frame homes are easier and cheaper to build and also easier to add insulation too which is necessary in most Canadian and northern US locales.
When used in conjunction with drywall, wood-framed homes are thus the obvious and popular choice for North American cities that also experience a higher population growth than many European cities.