Stucco has a major advantage over wood siding. It does not rot and so it can go a long time without the need for a protective coat of paint. A good stucco job will often maintain its original look for decades in many climates.
This means when you get tired of the colour, painting is often about aesthetics and not about protection. One disadvantage to unpainted stucco is it’s difficult to clean. If it has absorbed a lot of dirt or has algae growing on it, often they will leave behind stains.
The good news is that stucco is one of the easier surfaces to paint. Are you ready? Let’s roll!
What Kind of Stucco Do I Have?
There are two main types of stucco finishes: cement based and acrylic. Older homes tend to have cement-based stucco with a white finish to it. Starting in the 80’s, acrylic stucco became popular. It is easier to apply and it can be tinted to almost any colour.
Traditional Stucco
Traditional stucco can be troweled to a smooth finish. To make it look more interesting there are a number of swirls and blotches that can be added to the finish.
Although acrylic stucco was the predominant stucco for about 40 years, traditional stucco is making a comeback.
Acrylic Stucco
You can also identify acrylic stucco by its granular finish. It looks kind of like sliced bread. Don’t eat it!
It is manufactured with grains of sand in it that drag when the stucco is troweled on to the wall. As the trowel drags along these little grains of sand, they leave tiny channels in the finish which give it the textured appearance. This mean you can never trowel it to a smooth finish.
What about stucco with rocks?
Rock dash stucco is a simply traditional cement based stucco that has had a dash of rocks (instead of a dash of salt!) flicked onto it while the stucco is still wet and fresh.
In some places you will see stucco with glass chips, which is called bottle dash stucco. This is also a cement based stucco.
There are other variations of dash stucco. They are cement based. Acrylic stucco does not lend itself very well to a dashed finish.
When Should Stucco Cracks Be Repaired?
Stucco cracks are common. They come in various sizes. The most common are hairline cracks. Less common are larger cracks. Either way, they only become a problem when they begin to let too much water in.
There are a couple of key indicators you will want to be aware of.
One indicator is the presense of efflorescence. This is white residue on the surface of the stucco that has been leached out of the stucco by rain water.
Efflorescence itself is usually not a problem. It is a signal that water has gotten in through a crack in the stucco. The more white that you see, the more water there has been going into the crack.
A second indicator that stucco cracks are a problem is water stains inside the house on the opposite side of the wall from where the cracks are.
Water stains inside are always a sign of a problem. If the stain is on an exterior wall, then most likely it is rain water coming in to the wall cavity.
Stucco cracks are not the only way that water can get into the wall cavity. They are one of the items you will want to check out when you look for the source of a rain water leak.
In any event, if you can see other building materials when you look inside a stucco crack, it is time to fix it before worse damage is done.
How Do I Fix Cracks in Stucco?
The best way to fix most stucco cracks is with the right caulking. The advantage of a high quality caulking is that it will stick to the surface and also remain flexible.
Cracks are caused by movement and there will likely continue to be movement after you repair the crack. You don’t want your repair material to crack as well, so using a flexible repair product will help prevent this.
How Do I Fix Small Cracks in Stucco?
Small cracks in stucco are the thickness of a credit card or smaller. That is, they will be 1/16 of an inch or narrower. These are best handled with a premium grade acrylic caulking that you would clean up with soap and water, and not with mineral spirits.
You will definitely want to use caulking that is paintable when it is dry. For this reason I recommend that you avoid silicone.
For acrylic stucco you will want an acrylic caulk that has sand premixed inside the tube with the caulking. This will help to match the texture of the stucco. For traditional stucco, you will want an acrylic caulk that is meant for concrete.
Applying the caulking is like piping icing onto a cake. Your best bet is to use a dripless caulking gun and cut the tip of the caulking tube so that the little hole in the end is about the diameter of pencil lead in a regular wooden pencil. Then just follow the crack as you dispense the icing (I mean the caulking!).
Apply it to about 12″ of the crack at a time. On acrylic stucco, use either an old paint brush or a kitchen sponge to mash the caulking into the surface and match the texture as best you can.
On cement based stucco, use your finger or a rag (either one dipped in warm soapy water) to wipe off the excess and force some of the caulking into the crack. These ones will be more visible after painting since the caulking is quite a different material than the cement based stucco.
How Do I Repair Medium Sized Cracks in Stucco?
If the stucco crack is as wide as one to two credit card thicknesses, then it is what I would call a medium sized crack. It is between 1/16 and 1/8 of an inch. These should always be repaired.
The best way to do it is to first brush a coat of stucco paint inside the crack. This process seals the surfaces inside the crack and ensures that the caulking will stick.
Important note! You can best accomplish this by first coating the stucco wall first. Push a little harder on the roller around those cracks and use a brush to paint the cracks that the roller missed.
If you brush the cracks first, on unpainted stucco, there is a risk that those brush marks will telegraph through the final coat.
Once the medium sized crack has been “primed” with a coat of stucco paint, you can caulk it as you would a small crack.
How Do I Deal With Large Cracks in Stucco?
Large cracks in stucco I will define as larger than 1/8 of an inch. These larger cracks are tricky. First, any repair will almost certainly leave a visible “scar”. Also, cracks this size usually indicate substantial movement.
Sometimes the movement is from a one time event, like the building settled. Sometimes the movement is ongoing because the building flexes in that spot.
If the crack is very old, it may be that it has let water in for years, causing building decay. As stated before, water can get into the wall cavity through other paths besides cracks.
If you are satisfied that the building structure is not rotten, you can go ahead and repair the crack. It is ideal if the crack is first primed with a coat of stucco paint.
Acrylic caulking, again, is acceptable on all types of stucco. You can use acrylic caulking on larger cracks, but it does shrink more noticeably on larger gaps. After 6 months to a year you will be able to see where the caulking has receded further into the crack.
Polyurethane caulking is extremely sticky but it does not shrink as noticeably. You will want to fill the crack as carefully as possible and wipe off the excess with a putty knife. No matter what, it’s stickiness will be rather noticeable on acrylic stucco.
Can I Repair Very Large Cracks in Stucco?
Knife grade patching material is also an option for even larger stucco cracks. If the crack is deep, you will want a cement based filler to fill the deeper part of the crack. It would be fidgity work, meaning you carefully use a stick to stuff the deeper part of the crack with the cement based repair material.
When the first layer of repair material has dried, you would use a putty knife to to apply the knife grade stucco repair material. In 6 months to a year, there will likely be a hairline crack down the middle of the repaired large crack.
Summary of Repairing Stucco Cracks
When should stucco cracks be repaired? When there is a risk of something undesirable getting into the crack. If rain or lawn sprinklers are a threat, then the crack needs to be fixed. If insects are wanting to breach the gap and eat your house, then it’s time to fix the crack.
Although there are several ways to repair stucco cracks, the end result is not always pretty. That’s the way stucco is. You can’t sand a repaired area smooth like you do with wood or interior drywall.
Another problem is that repair materials often shrink over time and become noticeable.
If you are using standard stucco paint, the best practice is to first caulk the hairline cracks. Then paint the first coat on the wall, or on the whole house. This “primer coat” increases the ability of caulking to stick inside the cracks. After the first coat of paint is dry, go around and caulk the remaining cracks.
If you are using elastomeric stucco paint, then you generally should apply the first coat before repairing any cracks. The reason is that many elastomeric paints will permanently fill cracks up to 1/8″ wide. There will be fewer that need caulking.
This does not mean I am recommending elastomeric paint for your project.
Elastomeric paint has its own set of characteristics and may be harmful to some buildings. It is stretchy which gives it the ability to hide new cracks that appear after the painting is complete. It is thick and goopy, meaning it fills existing cracks.
Elastomeric is also a waterproofing solution. The downside is the way in which it is classified as a breathable waterproof coating. It might not breathe fast enough to let moisture out when there is a water leak. This causes a building to rot.
Have you ever worked up a sweat inside a GorTex jacket? You can see what I mean. Breathable membranes don’t always breathe as fast as we want them to.
What is the Best Way to Clean Stucco
Pressure washing is usually the best way to clean stucco before you paint it. A good gas powered pressure washer will remove dirt, grime and organisms. There are several organisms that often exist on stucco.
Moss will sometimes grow on stucco. Algae is a green a organism that does not have tufts like moss does. It looks like a living stain growing in the stucco. Mildew looks like a lot of black dots in one area.
These organisms should be treated with a bleach and TSP mixture to kill them before you pressure wash. The algae will go bright green after you hit it with bleach.
There are safety issues to be aware of when doing this. Bleach can damage your body by chemically burning it. A pressure washer can cut your flesh open due to its extremely high pressure.
No matter how aggressively you pressure wash organisms, they often will leave behind a stain in the porous stucco. This is normal. The bleach mixture makes sure that the residue of from the organism is dead and unable to push off your paint coating.
Use caution around doors, windows, soffits and cracks. What we don’t want is to force water into the structure of the house. Rinsing off the bleach/TSP mixture is critical. TSP is great for cleaning, but it may also act as a fertilizer when you don’t want it to.
Are There Alternatives to Pressure Washing Stucco?
If you are unable to get a pressure washer, you can also clean the stucco with a car wash brush and a garden hose. It requires a lot of elbow grease, but the TSP will do a great job of loosening dirt so that you can rinse it off. Scrubbing with the brush is essential to help the TSP do its job.
You may need two brushes, a soft one and a stiff one, in order to cover all your bases. A soft brush will do for most of the areas, and a stiff brush is good for moss after you kill it with bleach.
It’s helpful to think about washing a car. A touchless car wash almost never cleans the stubborn dirt from a vehicle. You have to work it over with a brush (or soft mitt) to get it nice and clean. The same goes for a house. (usually a brush – I’ve never taken a mitt to a house!)
What If I Have Peeling Paint on My Stucco?
It would be unusual to find peeling paint on stucco, but it does happen. Causes include poor quality paint, painting dirty stucco, or water in the wall that pushes the paint off. If there is a lot of peeling paint on stucco, it’s a significant problem.
If you do a mediocre job of removing the peeling paint, and then paint over what’s left, likely your paint job will fail. There will still be old loose paint that lets go and flakes off, bringing your paint with it.
The most common option is to pressure wash aggressively with a turbo nozzle. You should then paint the next day and hope for the best, but there are no guarantees.
A second option is to wet blast the old coating off. Wet blasting is when sand and water together are used to blast off the old paint.
It can be very successful. This approach requires special equipment to work with your pressure washer. Also, you have to clean up the sand at the end of the job and dispose of it safely.
A more extreme option would be to hire a contractor to soda blast the old coating off. Hopefully you are not facing a choice like this!
If there is efflorescence with flaking paint, there is a probably a serious leak somewhere that needs to be repaired before you paint.
What Equipment Do I Need to Paint Stucco?
The best way to paint stucco that has never been painted before is with a roller. Spray painting raw stucco is not recommended since it does not work the paint into the porous surface. Pushing on a roller will force the paint deep into the uneven surface.
A spray painter is acceptable for transporting paint out of the bucket and onto the stucco if you work it in with a roller right away. This is called “back rolling”. If you have access to a paint sprayer, this process can make the job a lot easier. In fact, it is the preferred method for unpainted rock dash stucco.
When unpainted stucco gets spray painted, the finish tends to deteriorate quickly. It may not flake, but it does look rather blotchy before long. Experience shows that this is true. Here is my theory about why.
The paint sits on the outermost and rough surface of the raw stucco. In this state, the paint does not consolidate into one big interconnected paint coating. It is bunch of disconnected and dried paint blobs.
Along comes the sun with its UV rays and it begins attacking these blobs and breaking them down at a fast rate. Much faster than if they were one big solid paint coating.
A paint roller will make sure that the entire surface is completely saturated with paint. This drenching of paint will all dry as one connected unit. United we stand!
Paint Equipment List
The Roller Equipment
- Empty 5 gallon bucket (fill half full with paint)
- Metal roller grid to go in the bucket
- 9″ roller cage
- 3/4″ or 1″ roller sleeve
- 2′-4′ extendable roller pole (this is the one that you’ll take up the ladder with the bucket)
- Assortment of longer roller poles (for using from the ground)
- Parachute cord (to make a leash for the 2′-4′ pole)
- Small keychain carabiner (to tether the other end of the leash to the bucket handle)
- Electrical tape ( to prevent the leash from sliding along the pole)
- 36″ of rope that can hold at least 200 pounds
- Regular climbing carabiner to use with the rope, for suspending the bucket from a ladder
The Other Paint Equipment
- Empty 1 gallon can to use for brushing around windows
- Pot hook to hang the can from your ladder
- 3″ angled sash brush, nylon polyester blend.
- Painters tape
- Painter’s plastic
- Drop sheets
- Old bed sheets for wrapping around shrubs
Process For Painting Stucco
The process for painting stucco is straight forward. You need a dry day with no rain in the forecast. The stucco also needs to be cured for 30-60 days if it was recently installed.
Choose a wall, preferably out of the sun. Protect all the non stucco items on the wall with plastic and tape. Put drop sheets on the ground below the wall. Then, roll your first coat on the wall from the bottom to the top, working out of the bucket that has the metal grid in it.
The roller cage is built with a tab where the grippy handle meets the wire frame. This is for hanging the roller from the top of the metal grid. If you were to plunk the roller right into the paint, it would fill up the hollow sleeve with paint and make a mess.
Painting bottom to top with an unpainted surface is advisable for the first coat. If you have big drips of paint, they won’t drip onto an unpainted surface. This increases the likelihood of a nice even finish.
If you have done a nice job of covering the windows with plastic in the middle and tape around the edges, then you can bump the window edges with the roller. This reduces the amount of brush work.
At the top of the wall, you can tape the soffits too, but be careful. If you put up a 1″ strip of tape on the soffit, it will not protect the soffit from roller hits. I recommend careful brushing instead of covering soffits and bumping them with the roller.
When masking the soffits seems like your best option, it’s also a good idea to try a 4′ stretch of tape as a test. Brush along it, let it dry and peel off the tape to see if you are happy with the results.
Along the soffits, the paint does not have to be thick. All you need here is a color change. This means you can try another approach. Tape the soffit, do the brush work with a light coat, and then peel off the tape while the paint is still wet and has not had a chance to bleed under the tape yet.
If you have stucco soffits you might choose to paint them too. Then, this brushing process will be performed along the back edge of the fascia boards.
If you do use tape, I recommend a high grade of painter’s tape to reduce the bleeding behind the tape. Also, it’s best to remove the tape within 24 hours, and always before rain gets on the tape. A lot of tape gets welded to the window frame when it gets hit with a rain-and-sun cycle.
When you do the second coat, you can work from the top down. This gives you the opportunity to finish any loose ends while you are up there.
Unless you have a crew to get a lot of work done, you may find it simplest to complete one wall at a time: first coat, second coat, remove plastic and tape. Done. However… a lot of hot sun is not great for the paint. You may want to work on two walls at a time to stay out of the sun.
What is The Best Paint for Stucco?
When painting exterior stucco, the best paint is a premium acrylic house paint. It is water reduceable, remains flexible, is resistant to UV rays from the sun and tends to hold its color very well.
Painters debate what the best finish is for stucco, either a flat finish (matte) or a satin finish. I prefer satin because it is easier to clean and is not too shiny. If you use a premium grade from your paint store, either finish will serve you well.
The paint store will tell you if a primer is required for new stucco. In my experience, if the stucco is fully cured then no primer is required. There is an exception. If there are ongoing issues with efflorescence, then a primer may be required.
How Much Paint Do I Put On When Painting Stuccco?
When you paint stucco with a roller, the important thing is to make the surface completely wet with paint. There should not be any tiny areas that are missed. You want to accomplish this with both coats of paint.
Once you have worked the paint into the roller in the first couple of minutes, it should be simple to achieve this. You will have to dip the roller often, especially on dry, porous, unpainted stucco.
A saturated roller is the best tool for painting stucco. From a painting point of view, its a simple task. Physically, rolling a whole house is a great workout for the arms. Suns out, guns out!!