Why Does Caulk Not Dry? (Answered)

Caulk is a quick fix for sealing and waterproofing various surfaces at home, from the kitchen to the bathroom.

In the ideal situation, caulk should dry as soon as you apply it to the surface.

However, the curing may take up to a week depending on the conditions and the type.

If you notice that caulk is not drying as fast as you would expect, you may want to read this article as I share some of the limiting factors and what you can do to speed up the process.

What Causes Caulk to Not Dry Quickly?

The Amount of Moisture in the Atmosphere

If the air around the area you seek to seal is saturated with water, your caulk will take a long time to dry.

This is common in kitchens and bathrooms, as lots of water is used there regularly.

Unfortunately, a high amount of water may also slow down the curing process. Read on to know how to deal with the problem.

Age of the Caulk

If you’re like me, you bought caulk a while ago to repair problem areas as they arise.

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While this is convenient, caulk is likely to get very old before you have used it all.

Unfortunately, caulk has chemicals that deteriorate with time.

Therefore, if it has been around the home for a long time, it may not be effective in sealing joints and waterproofing as required.

The Type of Caulk

There are three main types of caulks with different formulations that affect their drying and curing. Here is a quick look at each.

Silicone Caulk

Silicone caulk is commonly used with metal, ceramic and metal. This is because it is able to adhere to non-porous, smooth surfaces well. It is commonly used in kitchens and bathrooms.

Most silicone caulks can dry within 30 minutes but need up to 72 hours before they can fully cure. During this time, ensure that the conditions are right.

Acrylic Latex Caulk

An acrylic latex blend is best for filling small joints and gaps in wood, especially if you intend to paint the surfaces later. Some companies add silicone to improve its waterproofness and flexibility.

It may take up to 24 hours for the caulk to dry and up to seven days to cure.

Polyurethane-Based Caulk

While polyurethane-based caulks can be used indoors, they are commonly used outdoors due to their ability to repel dirt, have greater elasticity and create a watertight seal.

Unfortunately, it takes longer than other caulks to dry and cure. Give it around 72 hours to dry and up to ten days to cure.

The Temperature Impacts the Caulk Drying Time

Ideally, you need a temperature of between 40- and 80-degrees Fahrenheit for the calk to dry and cure effectively.

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When it is very cold, avoid using polyurethane-based caulks as they will take a very long time to dry and may not even cure well.

The Size of Gap

The amount of caulk you will use to seal a gap impacts the drying time. If you have a large gap to fill, it will take quite some time before it dries or cures.

Painting Over Caulk Too Soon

You can paint over many types of caulks. However, you should wait until the caulk has partially dried before you apply a coat of paint over it.

Otherwise, it may feel “soft” over an extended period. Ideally, you should paint over the caulk when it is no longer soft to touch and pinching.

What to Do When Caulk Does Not Dry

Check if you have used the right caulk

Pick the best caulk for the surface you intend to seal. Other types may not dry or bond well.

Use new caulk

If your old caulk has been around for over a month, consider buying a new one. Besides, check the expiry date when buying new supplies.

Proper aeration

If the room where you wish to apply caulk has lots of moisture, you may consider aerating the room by opening doors and windows.

You may also avoid using faucets for a few hours to let the caulk dry.

Raise the room temperature

As explained earlier, very cold environments may cause the caulk to dry fast.

However, do not attempt to heat the caulk using heaters and hair dryers.

Instead, increase the room temperature by a few degrees to make conditions more favourable for the drying of the caulk.

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Why Is My Caulk Still Wet?

Some of the factors that may prevent caulk from drying include the following:

• Low temperatures
• High humidity
• Caulk age (if it is too old, it may not dry at all)
• Temperature of the location where you have applied caulk
• Size of the gap you intend to seal
• Painting over the caulk soon after

Check if you have countered all the factors above before removing any caulk that is not drying. If none of the interventions work, remove the existing caulk and apply a fresh one.