Repairing Hairline Cracks In Exterior Stucco

Repairing Hairline Cracks In Exterior Stucco

Repairing Hairline Cracks

Many homes that have stucco as an exterior coating have cracking issues, but most of them can be repaired quite easily. There are different kind of cracks that appear and knowing how to go about fixing them is half the battle.

There are different kinds of cracks, distinguished mainly by their size and pattern on the wall itself. One can determine the cause of the crack by looking at the wall’s design, the size of the crack and the pattern.

These cracks are anywhere from 1/16 of an inch to 1/8 of an inch wide (typically) and are easily and effectively repaired using caulking and paint.

Materials Needed:
  • Caulking Gun
  • Caulk (latex with silicone base is recommended, 35 year)
  • There are also tubes that do not require a caulking gun (shown below)
  • Bucket of water
  • Sponge or Rag



Step 1: Cut Tip Of Caulking:

The first step is to cut the tip of the tube of caulking as small as possible, at an angle, if possible. I included this as a step because it is oftentimes overlooked and can make a huge difference in the amount of time it takes to complete the project, how much cleanup there will be, the finished product,etc.


Helpful Tip:
The smaller the tip, the easier and cleaner it will be to apply the caulking, the less cleanup you will have to do and the better the repair will look.

Then load the caulking gun with the tube and squeeze out some of the caulking, so your ready to go and have an idea of how much material is going to come out.

Cut Caulking Tip Off At An Angle


Step 2: Apply Caulk Spread Into The Crack

Next, you will want to apply a bead of caulk along the crack in an even and generous manner. Use the angle on the tip to your advantage, it will be easier to fill the crack this way.

Be sure to have a consistent bead without any gaps, you will want the entire crack to be covered in a bead so it is sealed entirely.

After the caulk is applied, take your finger and rub the caulk into the crack. Try to go all directions, in order to fill the crack entirely. Try to avoid spreading the caulk all over the wall, if you can do so, it will make the next step much easier.

Apply Caulking To Crack


Step 3: Wipe Off Excess Caulking

Now, take your sponge or rag and saturate it in the water. Ring it out a little bit, but Wipe Off Excess Caulkingkeep most of the water inside, it is better to have more water than not enough. Use the rag or sponge to clean up the area around the crack, while keeping the caulking inside of the crack itself.

Do not worry if you are shy on material here because we will end up applying a second coat that is textured and will fill in the rest of the material you need. Just make sure that the entire crack is filled and you didn’t miss any spots, this is critical in this step!


Helpful Tip:
The final product should just have the caulking inside the crack and nowhere else. Try to clean around the edges as good as you can for a better end result.



Step 4: Let The Caulking Dry

Let it dry for a day, or a few hours, depending on the instructions , weather, temperature, etc. Caulking has a tendency to shrink up a bit, which will work to our advantage, in this case. We will apply another coat of caulking the same way we did in steps 1 through 3 but add a little texture this time around, to match the existing texture.


Step 5: Texturing The Second Bead Of Caulking:

After we apply the second bead of caulking and wipe off the excess, we will want to add a bit of texture to make the repair blend in a little better. Before you try to texture to the wall, play with it on a piece of cardboard to try and simulate the texture and find out what methods (dabbing with a brush, using a sponge, etc.) will match the existing texture the best.

  • If you have a smooth texture, then this will be easier to do and will only require (in most cases) to keep reapplying caulking until it is flush with the finish and make sure there are no “hard lines” in the caulking, everything should blend in naturally.
  • For moderately heavy to heavier textures, a brush used in a dabbing motion would match the existing texture better. Experiment first, like I mentioned earlier to see what method works the best for your texture.


Step 6: Apply Color To The Repair:

For the repair to be complete, you will need to apply a matching color coat on top of the area you fixed and possibly the entire wall, so it blends in better. Most folks just paint the wall and is probably the easiest method and most cost effective one.

If you want to avoid painting, then look into a fog coat (traditional cement based finish) or an acrylic finish that was used on your home (custom color matched) that has the aggregate taken out of it. You can achieve this by running the material through a mesh paint screen, which will keep the color in tact but remove the aggregate to make a custom acrylic paint.


Helpful Tip:
It is hard to match the color of stucco exactly because it is porous and the color matching programs that are used these days will pick up on the “shadowing effects” that the uneven surface of the finish has. Keep this in mind if you are planning on painting and need to have your stucco color matched.


Helpful Video That Explains The Basics Involved:


The Stucco Guy

My name is Ryan and I have been in the construction trades for many years now and I feel that there is a huge "knowledge gap" when it comes to particular trades.... like stucco. I made this site to inform others about the simplicity of the art and that many people can do stucco themselves, if they put their minds to it. I hope you find the information here useful and please don't hesitate to contact me by leaving a comment. Thanks for stopping by! (Pic Coming Soon!)

16 thoughts on “Repairing Hairline Cracks In Exterior Stucco

  1. Dana

    I am a house painter and need to repair a small corner where the stucco was damaged. ( only about 3″x1″) can I mix of a little grout and put it on there or does it need to be stucco?

    1. The Stucco GuyThe Stucco Guy Post author

      I would recommend a pre-mixed stucco patch mix, which you can get for about $7 at Home Depot. The texture will match much better and the end result will blend in seamlessly, if the existing texture is matched.

  2. ed

    Previous owner did poor stucco crack repair. Lots of dried excess stucco. Tried sandpaper. No luck. How to remove dried stucco?
    Thanks for the site.

    1. The Stucco GuyThe Stucco Guy Post author

      Try a wire brush, it will usually remove the stucco if it is fairly fresh (1-2 weeks old) you can use a drill with an attachment as well and if that doesn’t work, then try a grinder with a masonry disc or diamond cup and start over. Hope this helps.

  3. MM

    I should have read this post first. As I did the silicone in the crack but I just pushed in with my finger and it spread on the outside of the crack also. Then I painted and you can see 6 huge streaks as I repaired over the garage and it looks terrible. I have done 4 coats on the wall and still see the streaks where the silicone was applied.
    Is there anything I can do to repair this? :(

    1. The Stucco GuyThe Stucco Guy Post author

      You would have to remove the silicone and try it again, it’s the only way. Try a putty knife and a wire brush.

  4. Anna

    How do I know if the cracks are superficial or because of structural problems?

    1. The Stucco GuyThe Stucco Guy Post author

      It is a tough thing to do without seeing it in person. Usually the size of the crack is a good indicator, on top of where you live, what is around the crack (windows, doors,etc.) so it is hard to answer but most of the time, cracks are not a serious issue (small ones anyways).

  5. deAnna

    I have many of these hairline cracks. Do you think they go through the two other coats under the finish coats?

    1. The Stucco GuyThe Stucco Guy Post author

      It’s hard to say without seeing it in person, but they usually tend to not. If the crack goes through the other two coats, they will usually be larger, more visible cracks.

    1. The Stucco GuyThe Stucco Guy Post author

      Thanks Carl,

      The cracks you are talking about are usually typical and nothing to worry about. If you were to fix them, it would be for aesthetic reasons and nothing more. If they get larger over time, then I would take a closer look at them and investigate the cause.

      1. The Stucco GuyThe Stucco Guy Post author

        It does work most of the time, remember to “add texture” to the caulk for a more seamless fix.


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