Here’s how to remove mortar stains without damaging your bricks
If you want to keep your bricks looking pristine, cleaning mortar off bricks needs to be on your to-do list. How do you clean mortar off bricks? While not complex, this task does require a mix of time and old-fashioned elbow grease. The payoff is that properly maintained mortar can last up to 100 years while looking beautiful. Follow along to learn what you need to know.
The reason why mortar removal is important is that mortar stains brickwork. As a result, your bricks can look sloppy. However, this is more than just an aesthetic concern. Displaced mortar can actually make brickwork insecure. Fortunately, you can remove mortar in just a few steps without the need for harsh chemicals.
The telltale sign that rogue mortar needs to be removed from your brickwork is that you're seeing smeared, splotchy stains around your bricks. This staining occurs because mortar dries rapidly following application. If mortar wasn't applied by an expert, there's a good chance that it will blur "outside the lines" of your bonded bricks. Of course, it's always wise to have a professional assess any worn-looking brick prior to investing in this project to get an opinion on whether you should repair vs. replace the bricks.
Start this project by preparing the surrounding area to establish a pristine and controlled work environment. Since a cleaning solution will be introduced later in the process for some methods, it's important to remove any objects that could be harmed by a cleaning product. Even excess mortar falling down can be harmful. If you have plants or landscaping in the trickle-down path of where you'll be cleaning, cover them with tarps. Tape all door frames and window sills with heavy-duty masking tape.
Using a brush to clean mortar from bricks involves washing the surface, applying a cleaning solution, and using a fiber brush to scrub the mortar off the bricks, working from the ground up. Depending on the size of the brick surface you'll be cleaning, it's important to leave enough time for this project. While cleaning mortar off bricks with a brush isn't overly technical, it can be a time-consuming process. You should also be in the right physical condition to perform repetitive movements with your hands.
Using your lawn hose or a spray bottle, spray down the surface of the brick you'll be working on. The reason why this step is important is because brick's density can make it difficult for the surface to absorb the cleaning solution you're about to apply. Water acts as a natural lubricant and barrier for brick that will make it easy for you to spread around the cleaning solution over the surface of the brick without the cleaning solution being absorbed into its pores.
No special products are needed to remove mortar from brick. Any standard eco-friendly commercial cleaner will work for this job. If you opt to use an acid cleaner that contains hydrochloric acid, it's important to know that this could cause a reaction that leaves your brick discolored. While most people advise against using acid cleaners when removing mortar from brick for this reason, the go-to rule is that you'll need to remove any existing yellow-green discoloration on your brick first to avoid this reaction.
As you apply cleanser, start from the ground up to ensure an even application without risks of the cleanser dripping down. If you're using an acid cleaner, you'll need to read the directions on the label carefully to see how long it can be left on the brick. Regardless of the type of cleanser you use, the goal is for the solution to soften the mortar in order to make the next step of scraping and scrubbing more manageable.
For this step, a high-quality fiber brush is recommended. Consider picking up a few extra if you'll be scrubbing a large surface area. Any type of brush or scraper with metal should be avoided because metal can create adverse reactions with some types of cleansers. Expect for some mortar stains to be more stubborn than others as you make your way across the brick. If you come across a spot that will not budge, you can add more cleaning solution to that spot before returning to scrape at it again.
Once you have scrubbed all of your brick, step back a bit to see if you missed any spots. If you're satisfied with your work, the final step is to rinse your brick. Do this using a hose while rinsing from the "bottom up" for good drainage. Don't move the masking tape or tarps that you applied during the prep stage just yet. It may actually take your brick 24 hours or more to fully dry after rinsing.
How do you clean mortar off bricks if a brush doesn't work? If you have especially stubborn mortar stains, you may want to approach them with a chisel. You’ll start by wetting the bricks, then you’ll use a chisel to break up the dried mortar. Lastly, use a brush to remove any remaining mortar fragments on the surface of the bricks. While this can be a painstaking process when done as a DIY project, it may be the only way to remove mortar that is resistant to scrubbing.
Using a garden hose or sprayer, wet the full brick surface you'll be working on. This will help to soften mortar slightly to make the job easier for you. It also helps to protect bricks against force-related damage.
Your chisel should be positioned at a parallel angle to the brick you're working on. When addressing stubborn built-up mortar, hold the chisel at an angle of 30 degrees when tapping. Be careful to only give the chisel a light tap as you try to break up dried mortar that is stuck to the brick. While you may feel eager to pick up the pace, continue to do slow, careful work with each new patch of mortar you approach. If you're dealing with large chunks, strategize to break them up into smaller pieces instead of trying to pry off large pieces all at once.
Once you've pried large mortar chunks from your brick, go over the surface of the brick again with a wire brush to remove any mortar dust or fragments. You can also go back over any mortar chunks that weren't successfully removed the first time with your chisel.
If you've inherited a home with existing brick, it's impossible to go back in time to undo the poor workmanship that caused mortar stains. However, you can move forward in the right direction to ensure you don't have to tackle this project again in the future. Here are some tips to prevent mortar stains on brick:
If you've noticed damaged or cracked mortar during this project, use your chisel or brush to remove a tiny piece that you can bring to a local brick supplier or masonry store. This will allow you to repair the issue using mortar of the same type, color, and consistency.
When doing mortar work, always give mortar enough time to dry before attempting to wash your brick. It can take mortar a full month to cure in some cases.
Consider having all future brick installation or repairs at your home done by a licensed masonry or siding expert.
If you're wondering if DIY mortar removal will save you money, it's helpful to know that removing old, cracked mortar can cost between $300 and $500 on average. Most masonry experts charge between $10 to $20 per square foot when a project includes removal and some refilling. While mortar removal from brick can be a DIY job, the high risks for staining or weakening brick if the wrong products or techniques are used make this a job that's best left to licensed siding repair experts near you. If you live in an older property, there may be local or district-level laws regarding how historic brick restoration must be completed.
Discoloration ondifferent types of brick can range from harmless to red flag. For example, efflorescence that is caused by a buildup of water-soluble white salt is considered harmless. However, green or greenish-yellow stains are caused by salts that are harmful to brick. Staining can also be caused by rust, corrosion, lime run, soot, algae, or moss.
Acid cleaners can cause stains on bricks. However, the staining isn't necessarily caused by the cleanser. It is actually caused by a chemical reaction that occurs when manganese deposits that are sometimes found on brick are exposed to acid.
No, using a power sander on brick is not recommended because the force of the sander can destroy brick's fragile outer layer. Even using sandpaper on brick is discouraged because of the damage its abrasiveness can cause.
