Polyurethane is one of the most popular and versatile products in the world.
Flexible, strong, and durable, polyurethane has many different uses including as a sealant for wooden surfaces such as tabletops and floors.
And while there are fast-drying, water-based versions of polyurethane, just how long does it take to dry once you apply it on a hardwood floor surface?
Polyurethane Floors Drying Time
|Drying time between coats:||6-8 hrs||24 hrs|
|Dry to touch:||24 hrs||48 hrs|
|Ready to place things like furniture:||After 2 days||After 4 days|
|Completely cured for full usage:||20 days and plus||30 days and plus|
In this article we will cover:
Drying Time of an Oil-Based Polyurethane
Put simply, it takes about 24 hours for oil-based polyurethane to properly dry.
If you are applying polyurethane to a wooden floor, it is advisable that you do not walk on the surface with shoes until 48 hours have passed.
Once the first 24 hours of drying time have been completed, you can walk across the surface in your socks.
Be sure to keep pets away from the area during the complete drying time.
To know whether the surface has dried enough to walk on, give it the sniff test to detect any odor.
Then, apply your hand to the surface to feel if it is tacky.
If you do not smell the odor and the surface is dry and not tacky, then you can walk across it while wearing socks.
After 48 hours have passed, you can walk across the floor in your shoes which is no problem.
However, you should wait at least 4 days before moving the furniture back into the room.
That is because the polyurethane has yet to cure which means that moving furniture may cause damage at this point.
For pets, you should wait at least 14 days before allowing them into the room.
This will allow the polyurethane to properly dry and start to cure so the pets cannot do any damage.
Finally, after 30 days the oil-based polyurethane will properly cure.
This will allow you to put back all the coverings such as rugs that were in the room.
Drying Time of a Water-Based Polyurethane
Water-based polyurethane does not take nearly the amount of time to dry as compared to oil-based versions.
On average, it takes about 6 hours for water-based polyurethane to dry under the same conditions that apply to oil-based polyurethane.
As with the oil-based polyurethane, give it the smell and tacky tests to ensure that it has fully dried.
Once it has dried to the touch, you can add a topcoat or do a little sanding to the surface.
After 24 hours, you can walk across the hardwood flooring surface in your shoes.
And 48 hours after that, you can set up your furniture inside the room.
Pets should be kept out for at least one full week after that to ensure that the polyurethane is fully dried.
After 30 days, you can now use rugs to cover the floor.
Drying Time vs. Curing Time: What is the Difference?
There is when the polyurethane dries and when it cures into the wood itself.
While the drying time of water-based polyurethane is 6 hours and oil-based is 24 hours, the curing time can last up to a month depending on the conditions.
This is because drying and curing are two different processes even though they seem roughly the same.
When the polyurethane is dry on the surface after 6 or 24 hours depending on which type you use, then you can add another coat or do a little sanding.
Curing is when the polyurethane bonds with the wood itself.
The drying allows the polyurethane to seal the surface of the hardwood.
The resin on top is a protective layer that can prevent spills from penetrating the surface.
Since water evaporates faster compared to oil, that is why water-based polyurethane can dry far more quickly compared to oil-based.
However, both types still take about 30 days to fully cure.
The curing process follows the drying phase. It is during this time that the resin on the surface and in the wood hardens to provide a plastic-like form.
This is when the poly resin reacts to the oxygen in the air and crosslinks with the molecules of the polymer to create a tri-dimensional matrix.
Crosslinking is the process where two molecular bonds are created.
For the curing process, polyurethane creates a polymer molecule that crosslinks with oxygen.
The result is a stronger bond of the polyurethane to the wood.
The more coats of polyurethane you apply to the surface, the more the crosslinking process will occur.
This means you are adding additional protection to the wood flooring, but you normally do not need more than two coats or layers of polyurethane to achieve the best results.
Because the crosslinking process takes time, this is why 30 days is recommended before you put all your items on the floor such as rugs.
Factors that Influence the Drying and Curing Time of Polyurethane
While the drying and curing times represent good averages, they are factors that may increase or decrease the amount of time in which they occur.
This is normally due to any chemicals that may be inside the wood which interact with the polymers.
Such interactions can affect the crosslinking process which may increase or decrease the drying or curing times.
a) Sanded Surface:
If you lightly sand the surface of the wood, it will absorb the polyurethane faster and cause the drying times to decrease.
b) Type of Wood:
There are certain types of wood, such as Rosewoods or aromatic cedars that can make the crosslinking process take longer.
c) Temperature and Humidity:
Temperature levels above 70F degrees and humidity levels above 70% will increase the drying times for both types of polyurethane products.
In addition, the drying time increases if the temperatures are much cooler, and the air is considerably dryer.
Using a fan to circulate the air without blowing it directly on the polyurethane may decrease the drying times as well.
d) Type of Polyurethane:
Basically, it takes roughly 6 hours for water-based polyurethane to dry and 24 hours for oil-based polyurethane to dry.
After the allotted time has passed, you can do a little sanding and walk across the floors in your socks.
However, it does take a full 30 days before both types of polyurethane are cured.
Remember to use the odor and tacky test to ensure that the surface layer has fully dried before walking across it in your socks or sanding areas that need more attention.
It is possible to significantly decrease the drying time if you sand the surface lightly and add air circulation if the temperatures are below 70F degrees.
The dryer the air, the faster the Minwax polyurethane will dry as well.
So, you can speed up the drying process significantly if you apply the right tools and keep the air dry and cool.
Hi, I am Mark Garner a professional carpenter, woodworker, and DIY painter. I live in the small city of Peoria, Arizona as a semi-retired woodworker. I have started this blog with a simple motive to help you with my wood experience in this sector. If you like to know more about what I love doing and how it all got started, you can check more about me here.