Anyone who has hung and mudded drywall intimately knows the concept of working time vs. total time. Applying the joint compound (also known as mud) to the drywall often can be accomplished quickly. A skilled drywall worker can finish a wall in minutes: working time.
But total time is another matter. Waiting for drywall joint compound to fully dry before other layers of mud or paint are applied can take days. How long does it take for the joint compound to dry—and is there any way to speed up the drying process?
How Long It Takes For Joint Compound to Dry
Properly installing drywall requires not just effort but also plenty of time, particularly when it comes to drying time for each coat of drywall mud.
Drywall joint compound manufacturers are hesitant about providing targeted drying times, preferring instead to provide a wide spectrum and then leave the rest up to the user. The reason is that so many factors are at play: room temperature, product temperature, application thickness, type of application, humidity, and type of reinforcing tape or bead.
At the far end, drywall mud, also known as joint compound, needs to dry for 24 hours between each coat and before sanding, priming, and painting. The 24 hour drying time recommendation can be applied to nearly all factors. Some manufacturers will bring down that number to 12 hours if a few shortcuts are applied to help speed up drying time without affecting the finished product.
Watch Now: How to Properly Finish Drywall
How to Speed Drywall Mud Drying Time
Apply Thinner Coats
Just like when you're painting, applying thinner coats of drywall mud means it takes less time for each layer to dry. This is the single best way to decrease drywall dry time.
The first coat that you apply will take the longest, as it needs to be the thickest to fill the joints between the drywall sheets and cover the screw holes. Once the initial coat is done, you can thin out the remaining coats quite a bit. Not only does this cut the drying time, but it also reduces the likelihood of indentations and future cracking.
Raise the Temperature
While you cannot change exterior temperatures, you can turn up the heat in a room that is being drywalled. To quicken drywall dry time, turn on the furnace or put space heaters in the room. For a small patch of wall, aim a hairdryer at the area. Keep the hairdryer far away from the patch.
Dehumidify the Air
Set up a dehumidifier to suck the moisture out of the room's air. Drywall mud is laden with water, so a dehumidifier will accelerate the process of moving water away from the wall system. Be sure to frequently check the dehumidifier's water pan and dispose of the contents.
Increase Air Circulation
The length of time it takes for mud to dry decreases when air is moving around the room rather than staying still. If it is not overly humid outside, open up the windows to circulate the air. However, if it is humid, avoid letting that humidity in, as it can actually slow the drying time. Set up fans in the room to get the air moving, whether or not you are able to open the windows.
Use Hot Mud
For time-sensitive projects, you can use a special type of compound known as hot mud.
Hot mud is a powder that you mix with water. It is formulated to set like plaster, so it dries in just 20 to 60 minutes. You can choose from products that have a faster or slower drying time. One downside is that the rapid dry time does not allow much time to fix errors. Be sure to follow the manufacturer's instructions for specific products.
The first time you use hot mud, apply it to only small areas to get used to how it works. If you need to mud a larger area, stick to standard compound until you feel that your skill level is up to par.
When using hot mud, mix only enough to fill the mud pan once. If you mix too much, you risk the mud drying before you use it all. In the same vein, wash your tools immediately after mudding, not only to avoid it drying on the tool but also because residual compound left in the pan can make the next batch set too fast.