How Long Does It Take for Polyurethane to Dry?

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how long does it take for polyurethane to dry

Polyurethane is one of the best finishes you can use for your home’s hardwood floors. 

Its heavy-duty sealing properties make it resistant to spills, marring and other damage. It also helps bring out deep undertones and patterns in the wood for a nice, deep finish. 

However, applying polyurethane can be a fairly complex and time-consuming process. In order to take advantage of its protective properties, you are going to have to do it correctly. 

In this article, we have laid out how long it takes for polyurethane to dry. This will help you plan out the application process and give yourself the time to let it cure properly. 

Average Length of Time it Takes for Polyurethane to Dry

Each coat of polyurethane will have to dry before you can add another one. Because of this, knowing how long this can take will let you be sure that every coat is applied correctly. 

Polyurethane typically dries within 24 to 48 hours. In this time frame, the coats will be dry in that they are not going to be tacky or sticky. 

It will not, however, be completely cured in this amount of time. Curing is when the molecules in the polyurethane have bonded together to be a solid, strong coat. 

Full curing can take up to 30 days. However, you can usually start replacing furniture and walking on the floor in just 2 days. 

The 24-48 hour time frame, however, is long enough to sand and add another coat.

Factors that Determine How Long it Takes for Polyurethane to Dry

factors determine how long to dry polyrethane

While these time frames are generally correct, there are a few factors at play with the drying process.

Knowing these factors can help you plan just in case you need to allow for some more drying time.

Polyurethane Type 

There are two types of polyurethane that are widely used: water-based and oil-based. The type of polyurethane top coat you use will play a major role in how long it takes to dry. 

Water-based polyurethane is generally thinner and provides slightly less protection. Oil-based polyurethane leaves a hard, heavy-duty finish that can safeguard your floor for years. 

One of the benefits of water-based polyurethane is that it takes much less time to dry. A coat will be ready to be sanded and have another coat added after just six hours. 

On the other hand, oil-based will take the full 24-48 hours to be dry enough for a new coat. 

Atmospheric Humidity and Temperature 

As with any liquid, polyurethane will react to the moisture and temperature of the air around it. 

High levels of humidity will make it harder for the molecules to bond to one another. This is caused by water molecules interfering with the connection points

Higher heat, however, will facilitate the drying process and help the bonding along. This is why painting and varnishing in the summer months is recommended. 

Generally, the drying times will not vary radically in less-than-ideal conditions. However, on colder, wetter days, you could be adding up to half a day more of drying time. 

Wood Type

wood type

The type of wood you are applying the polyurethane to will also affect the length of drying. 

Certain woods excrete chemicals that can interfere with the bonding process. This will increase the amount of time it takes to dry or even prevent a full cure. 

Woods like cedar and rosewood don’t take polyurethanes as well as others. If your flooring is made of one of these, it is best to use a water-based top coat. 

Surface Prep

One of the most important factors in your flooring’s polyurethane top coat drying is its preparation. A floor that is properly prepared will not only dry faster, it will also hold up for a lot longer. 

Before you begin applying the top coat, make sure that the wood is as sanded and raw as it can be. This will open up the pores of the wood and allow the polyurethane to sink into it. 

Sanding the wood smooth will also eliminate any dips or gouges in the surface. This will prevent pooling of polyurethane, which can affect the drying process and create wet spots. 

It is also incredibly important to make sure the floor is as clean as it can be before applying the first coat. Dust and debris can interfere with the coating of the wood and cause an uneven cure. 

F.A.Q.

faq how long polyurethane to dry

  • How long does it take for polyurethane smell to go away?

It can take up to 2 days for the smell of polyurethane to fully dissipate from your house. 

You should be aware that polyurethane can contain Volatile Organic Chemicals, which can be harmful. Always apply it with proper ventilation and plan accordingly for the drying period. 

  • How can I make polyurethane dry faster?

By waiting until the weather is hot and dry, you can facilitate the curing process. 

Midsummer is a great time to apply any kind of paint or varnish due to the ideal conditions. Dryness in the air will help create a strong bond with the wood and the top coat. 

  • Is 2 coats of polyurethane enough?

It is recommended that you use at least 2 coats of polyurethane on your flooring. 

However, since the floor is such a high-touch area, the more coats, the better. 2-3 coats should give you enough protection for heavy use. 

Conclusion

Properly drying your polyurethane top coat will go a long way towards protecting your flooring. 

By waiting the correct amount of time between coats and allowing it to cure, you can ensure it is strong. This resists dents and gouges and will keep hardwood looking new for many years. 

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AUTHOR

Michael J. O’Connor is a writer and marketing specialist from the Bay Area of California. A graduate of Sonoma State’s Creative Writing program, he spent many years as a contractor and carpet layer, learning the ins and outs of flooring and general contracting. When he’s not typing away at his desk, he enjoys hiking with his dogs, woodworking and collecting rare books. See full biography here.

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