Repairing Hairline Cracks In Exterior Stucco

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.

Repairing Hairline Cracks:

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

 

1) The first step is to cut the tip of the tube of caulking as small as possible, at an angle, if possible. The smaller the tip, the easier and cleaner it will be to apply the caulking. Then load the caulking gun with the tube.

 

2) 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.

 

3) 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.

 

4) Now, take your sponge or rag and saturate it in the water. Ring it out a little bit, but keep 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.

 

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.

 

5) Let it dry for a day, or a few hours, depending on the instructions , weather, temperature, etc. Reapply a second coat if needed.

 

6) Then paint the crack with a fine tip brush. It is better to paint the entire wall or house for a better color match.

 

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.

The Stucco Guy

Author: 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!)

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14 Comments

    • The Stucco Guy

      Your very welcome Robert.

      Post a Reply
    • Thanks, the sponge and water are a great idea

      Post a Reply
      • The Stucco Guy

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

        Post a Reply
  1. Nice article. How important is fine crack repair 1/16″ or less?

    Post a Reply
    • The Stucco Guy

      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.

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

    Post a Reply
    • The Stucco Guy

      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.

      Post a Reply
  3. HI,
    How do I know if the cracks are superficial or because of structural problems?
    Thanks,
    Anna

    Post a Reply
    • The Stucco Guy

      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).

      Post a Reply
  4. 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? :(
    thanks

    Post a Reply
    • The Stucco Guy

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

      Post a Reply
  5. 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.

    Post a Reply
    • The Stucco Guy

      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.

      Post a Reply

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