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What is Adhesive Caulk?

Donna Rengi
Donna Rengi

Adhesive caulk is a material used primarily in the construction and home improvement industries to join and seal seams. It adheres firmly to the surfaces and fills in the gaps. Filling in cracks with this type of flexible sealing compound not only helps prevent water from seeping into cracks, but it also prevents dust, air, or insects from getting into those cracks. Typically, adhesive caulk consists of ready-mixed materials such as silicone, polyurethane, polysulfide silyl-terminated polyether or polyurethane, and acrylic sealants.

What makes adhesive caulk different from other types of caulk is its adhesive property. Most caulks have a fixed lifetime, after which they have to be re-applied or “recaulked.” Adhesive caulk, however, typically has a longer life than many other caulks because of the additional adhesive properties in the caulk. Still, depending on the particular application of adhesive caulk, recaulking may be required.

Adhesive caulk.
Adhesive caulk.

While caulking, one has to be very cautious about the amount of caulk applied. Too much or too little of the adhesive caulk can affect the look of, as well as the protection afforded by, the caulking. Proper application typically requires that the surfaces to receive the caulk be cleaned. Alcohol is often helpful in removing any grease that might prevent a tight bond with the caulk. Proper application also requires that the manufacturer's instructions on the caulk itself be followed.

Applying adhesive caulk to a wall.
Applying adhesive caulk to a wall.

Caulk is a moist substance with a similar consistency to peanut butter. It's typically applied with the use of a caulk gun and works via a chemical reaction that causes the material to harden when exposed to air. Before hardening however, the caulk seeps into the crevice and even the small pores of the material to which it is applied. After it has dried thoroughly, one may choose to paint it to make it blend in with the color of the surrounding material. Alternatively, one can buy tinted adhesive caulk.

A person applying adhesive caulk.
A person applying adhesive caulk.

For general household caulking needs, acrylic caulk or silicone caulk can also be used. Acrylic caulking is generally preferred for a neat caulking finish. On the other hand, silicone caulking is generally used for applications that require water-resistance. Silicone caulk is popular because of its fire-resistant, non-stick, and rubber-like properties. It also has low chemical reactivity and low toxicity.

Some of the other common types of caulk are sanded caulk, gutter caulk, and fire caulk. Sanded caulk is usually used with tiling and other flooring applications. Gutter caulk is used to prevent leakage in gutters, and fire caulk is used in containing the flames and heat in a furnace or fireplace.

Discussion Comments


Adhesive caulk has a unique consistency. I remember touching it as a child and being fascinated by how rubbery it was.

I didn't touch it while it was wet, because I didn't want to get any bad chemicals on my hands. However, a day or so after it had been applied, I would put my finger on it and press down. It felt almost like a dry snail, because it felt springy.

You would think that something like this would be weak and not a good choice for sealing gaps. However, it was incredibly strong, even though it wasn't hard.

@wavy58 -- Silicone adhesive caulking is great for filling gaps, but it does have a really strong odor. I can't stand to be in the room while it is being used, and I have to avoid the area for hours afterward while it dries.

I suppose it depends on how soon your company is arriving. If they will be there within a day of the time that you plan to use the caulk, you should probably wait. It takes several hours for the odor to go away, and you might have to leave the window open to get the stink out.

To me, it smells like someone poured a bottle of vinegar on the floor. It doesn't bother some people, but no one can argue that it isn't noticeable.


I am considering using some silicone adhesive caulk around my windows. There are gaps where I can feel the cold outside air coming in, and I know that this is having a bad effect on my electric bill.

Does caulk have a strong odor? I am expecting guests who will be staying for a week, and I need to fix the windows in the guest room, but I don't want to do it if it will make the room smell bad. Should I wait?

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    • Adhesive caulk.
      Adhesive caulk.
    • Applying adhesive caulk to a wall.
      Applying adhesive caulk to a wall.
    • A person applying adhesive caulk.
      A person applying adhesive caulk.