The length of time plaster takes to dry is determined upon a number of factors such as whether you used plasterboard or backing plaster, the temperature, number of layers and much more. Although obvious, you can’t paint or wallpaper plaster when its wet because it can cause adhesion problems and simply be a waste of time.
During our time of renovating houses, we normally plaster the whole house and have plenty of experience regarding the drying of plaster. As you can see in the above image of plaster beginning to dry, wet plaster looks like an “earthy”/brown colour whereas dry plaster is much lighter and best described as a creamy pink colour.
Although undecorated plastered walls and ceilings aren’t great to look at, it’s worthwhile waiting for it to dry properly to avoid any issues. Below we discuss how long plaster takes to dry as well as tips and potential issues.
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Why Do You Need To Wait?
As briefly mentioned above, failing to allow plaster to dry can cause adhesion problems. For example, if you were to use emulsion paint on wet plaster, it may not bond properly and end up peeling away from the wall or ceiling. A similar issue will arise if you wallpaper straight onto new plaster that’s yet to dry because the wallpaper paste won’t bond with the wall.
How Long Does Plaster Take To Dry
From our experience, freshly plastered plasterboard can take 2 to 3 days to dry. However, if you have plastered backing plaster, it can take twice as long to fully dry. The layers of plaster used, time of year, central heating and other factors will all affect the time that it takes for plaster to dry.
However, even if its past the 2 to 3 day period of waiting for plaster to dry, it’s advised that you visually check the plaster itself. Before painting or using wallpaper, you want to ensure there are no dark patches whatsoever. If possible, waiting at least a week for plaster to dry before decorating is advised (as long as there is no dark patches).
How To Speed Up Drying Plaster
If you are working to a tight schedule or simply can’t stand looking at wet plaster any longer, there are methods you can use to speed up the drying process. One of the most effective methods is to use a dehumidifier in the room. However, you should do this with caution because drying the plaster too quickly can cause cracking.
The best method that we would recommend is plenty of ventilation (opening of the windows) and a low background heat. If you are too impatient and rush the drying process, it may cause issues that you’ll regret later on.
Before & After Results (Wet To Dry Plaster)
As you can see from the above photos, the plaster becomes much lighter in colour overtime, which is a good indication that its drying. However, before we began painting over the new plaster, we left it another few days.
Why Does Plaster Crack When Drying
If the plaster is beginning to crack whilst it’s drying, there are a few reasons why this may be happening. The first and most common is that too much heat is being used in the effort to speed up the drying process of fresh plaster.
Other reasons why the plaster is starting to crack can be due to wallpaper/woodchip being plastered over without removal, incorrect PVA ratio and even using out of date products.
Why Isn’t The Plaster Drying
If you have waited over a week and there is no signs that the plaster is drying, you may have a problem. There could be penetrating damp or a leak that needs investigating further. Plaster will always dry naturally but if it remains wet with dark patches, this may be a sign there is an issue and you shouldn’t try to force it to dry with heat.
Hopefully the above guide on how long does plaster takes to dry covers everything you need to know. Although it can be frustrating to look at plaster for a week or so before decorating, it’s strongly advised to do so. The last thing you want to happen is all your hard work of decorating to simply begin to peel due to the plaster not being dry. If you have any question relating to the drying process of plaster, feel free to get in touch with our team.