Paint removal is not an easy process, but it can be done. Whether you want to remove paint that has been applied deliberately, graffiti, or accidental paint splashes, there will be a way to restore your brickwork. It is important, however, to understand the type of brick and choose a suitable method that won't damage it. There are a variety of techniques that can be used, ranging from easy DIY jobs to more complex and technical processes that require help from a professional.
A simple way of updating the exterior brickwork of your home is to paint it, but it is never a good idea to apply paint directly to bricks. While it can look good, underneath, the paint will be causing damage.
Exterior paint like masonry paint is designed to withstand all kinds of weather conditions. To this end, it is airtight and waterproof. At first glance, it might seem that this would be beneficial to the bricks beneath, but this is not actually the case.
Bricks and mortar are designed to be breathable. They have a porous surface that absorbs moisture from both inside and outside the property, and then they release it again. When a waterproof layer is added to the brick wall, it prevents it from releasing moisture, which then becomes trapped in the masonry.
Over time, this trapped moisture can begin to erode the brick and cause structural damage. Even if your brick wall has been deliberately painted for aesthetic reasons, you should consider removing the paint and restoring the brick to its natural beauty.
Take a look at our post "Why does brickwork go white".
Before beginning the brick paint removal process, it is essential to determine what type of brick you are dealing with, its condition, and what type of paint is on it.
Old bricks, and especially historic bricks, are very different from modern ones. They tend to be larger, with a smoother face and, importantly for our purposes, they are more porous. This is because modern bricks are kiln-fired at a higher temperature.
Having a more porous surface will have two consequences with regards to paint removal. First, it makes them more susceptible to the problems associated with a painted brick surface, such as moisture retention and damage.
Second, it means that any brick cleaning methods need to be more carefully applied because the brick will absorb any water or material that is used to clean the paint, and they will be more vulnerable to damage. This could lead to crumbling or flaking during the cleaning process, or water damage if the brick gets too saturated.
Lead
Lead-based paints were banned in the UK in 1992. If your brick may have been painted before this time, or you don't know when the paint was applied, you should get it tested for lead before going ahead with the removal process. Even if the top layer of paint was applied after 1992, there may be lead-based paint layers underneath.
There are testing kits you can buy online, or you can contact a professional company for assistance.
Different types of paints have different chemical compositions that will influence what can be used to remove them. We'll examine some of the most common types you are likely to see applied to brickwork.
Latex paint is commonly used on both exterior and interior brick. It is a water-based paint that forms a flexible, rubbery film on the surface of the brick. It dries quickly, but remains relatively soft, and doesn't penetrate far into the pores of the brick. This makes it easier to remove than other types of paint.
Because it is water soluble, most of the time, you will only need water for the paint removal.
The best removal methods include:
Acrylic paint is similar to latex but it contains plastic resins for added durability and flexibility. It is the most common type of spray paint used for graffiti, but it is also commonly used as a masonry paint for areas that are high-traffic, and where paintwork needs to be more hardy.
Once it is dry, it becomes water-resistant, which makes it more difficult to remove than latex paint. It also adheres more strongly to the brick because it penetrates slightly deeper into the pores.
Because of these issues, it will need more stronger paint removal methods. These include:
This is a solvent-based paint made from natural oils or synthetic alkyd. Like acrylic paint, it is used on exterior surfaces because it is highly durable, and it is another type of spray paint that can be used for graffiti.
It forms a hard, durable finish that is weather-resistant and waterproof, and it penetrates deeply into the pores of the brick. It is one of the most difficult paint types to remove. Water-based methods will be ineffective because oil repels water.
Removing oil-based paint will require more aggressive methods. These include:
Now we have an idea of what methods work well for different types of paint, let's go into each one in more detail.
Before starting any paint removal job, you will need to make sure that the area and yourself are properly prepared.
Removing paint from brick can create toxic fumes and some of the methods used to remove paint can burn your skin and eyes. Because of this, it is important to ensure that you have all of the correct safety equipment before you begin.
This includes:
Removing paint can cause damage to elements in the surrounding area, so you should take steps to prevent this as much as possible.
Use protective plastic sheeting to cover any surrounding plants, window frames, wooden structures, and any other surfaces and materials you wouldn't want damaged.
If you are removing interior paint, such as a brick fireplace, you should always ensure that there is proper ventilation while you work. If you are in any doubt at all that the room is ventilated properly, you should consult a professional.
Before you begin the paint removal process, you should thoroughly clean the brick surfaces and mortar joints. Any dust, dirt, or grease creates a barrier that can prevent your paint removal methods from being effective.
Use soapy water, damp cloth or sponge, and a stiff brush for any stubborn areas, before rinsing with clean warm water.
View our post for more information "How to clean brickwork".
You can use pressure washing alone for water-based paints like latex, and it is often also used in conjunction with other methods for acrylic and oil-based paints.
Pressure washing uses a combination of water and mechanical power to remove paint, and it can cover large areas in a small amount of time.
Because of the high pressure, however, it can be easy to damage the underlying brickwork if the pressure washer is used incorrectly. A professional pressure washing company can ensure that the paint is removed without damaging the masonry.
Set the pressure washer to a psi of 2,000-4,000 then test it on a small, inconspicuous area to see how it affects the brick.
Start at a distance away and then move closer. You should aim for around 12-18 inches, and aim the nozzle at an angle, rather than directly parallel. Avoid keeping the water stream directed on one area for too long, especially mortar joints. These are much more susceptible to damage from pressure washing.
Work in small sections, and be particularly mindful of older bricks.
There are two main classes of paint strippers: solvent and caustic. Both are toxic and will burn skin, eyes, and lungs if inhaled. A high level of safety precautions need to be taken when removing paint with chemical-based strippers.
You can also get eco-friendly paint strippers, and these are safe to use indoors as they are non-toxic.
Most types of paint strippers can either come in liquid form or as a gel. Using a gel paint stripper is better for vertical surfaces as it sticks to the wall, rather than running down it.
Solvent paint stripper works by breaking the bonds between the paint and the surface by causing the ingredients in the paint to swell.
Caustic paint stripper works slightly differently from solvent. Its main ingredient is usually sodium hydroxide, and this works to break down the chemicals in the paint itself due to its high pH level.
It is much more dangerous than solvent paint stripper but is more effective for situations where there are multiple layers of paint or for oil-based paint.
Because it has a thicker consistency than solvent paint stripper, it is also better for use in areas where there is a lot of intricate detailing because it is better able to sit in the crevices.
These types of paint strippers use natural, non-toxic active ingredients to break the paint's bonds. They are safe for the environment and for human health, and can be used both indoors and outdoors.
They may not be strong enough to remove multiple layers of paint or for stronger adhesive paints like oil or acrylic.
Eco-friendly paints include:
Use a paintbrush to apply a thick layer of paint stripper to the brick, then allow it to sit for the recommended time in the manufacturer's instructions. This can be anywhere from 20 minutes to two hours.
Check if the paint has softened with a putty knife. If it is soft and easy to scrape off, then it is ready for removal.
Use a scraper, trowel, or wire brush to scrape the paint from the brick. Be careful not to scrape so hard that you damage the brick. You will go back in and repeat the process, so you don't need to remove every last flake of paint on the first go around.
Once you have removed as much as you can, apply the paint stripper a second time. This time, make sure you get it into all of the nooks and crannies. Wait the recommended time, and scrape off the remaining paint.
If you have used a caustic paint stripper, you will need to neutralise it. This stops the chemical reaction and protects the brick from damage. You do this by lowering the pH level, and an acid like vinegar will do the trick. Rinse the brick with water and then coat it in vinegar, scrub it in using a stiff brush, then rinse again.
Solvent and eco-friendly paint strippers will not need neutralisation.
Now, you can go back over the brick using a pressure washer to remove any remaining paint residue and clean the wall of the leftover paint stripper.
A heat gun uses heat to make paint soften and bubble, making it easier to remove with a scraper. They are safer than something like a blowtorch because they don't produce a flame, but they can still cause highly flammable materials to catch fire.
Because of this, you can't use a heat gun to remove oil-based paints, which are highly flammable. They are safe to use on water-based paints, as well as solvent-based paints like acrylic. While acrylic paint is flammable when wet, it dries to be non-flammable, and the plastics in it will simply melt.
A heat gun is an efficient tool that can be used to remove multiple layers of paint in one go, making the job faster than using a paint stripper. It still does require manual removal with a scraper, but it is overall a faster method.
Hold the heat gun 6-8 inches from the brick, and heat the paint until it begins to bubble and soften. Then, use a scraper, trowel, wire brush, or putty knife to scrape away the softened paint.
Don't scrape so hard that you damage the brick. Instead, if there are areas of paint that are still difficult to remove, apply the heat gun a second time.
You can use a pressure washer to remove the remaining paint residue from the wall.
A sandblaster is a tool that uses high-pressure compressed air to propel abrasive material, often sand, to a surface. It is effective and highly efficient at removing all types of paint.
Sandblasting with sand, however, is illegal in the UK because it can cause silicosis due to the inhalation of tiny particles of sand.
Shot blasting is legal, however, and uses grit, steel, glass, or dry ice instead of sand.
Shot blasting is still highly dangerous, and can lead to crush injuries, skin abrasions, and other serious bodily damage. Because of this, shot blasters can only be used by professionals with extensive training and OSHA-compliant practices.
If you aren't looking to remove paint from an entire wall, and have only accidentally splashed some spots of paint on brick, you can use much simpler methods.
A vinegar and water solution, baking soda paste, or non-toxic paint stripper can be used.
For the vinegar and water solution, mix equal parts vinegar and water, apply to the paint spots, and scrub with a stiff brush.
For the baking soda paste, combine three parts baking soda with one part water and mix to form a paste. Apply it to the paint spots and scrub with a stiff brush, then rinse with water.
Removing paint from brick is a labour-intensive, and sometimes dangerous task. In some situations, it can be completed as a DIY project, but many people choose to use a professional.
There are circumstances when, even if you want to do the job yourself, it can be a better idea to use a professional. These include:
If you need to remove from your brick exterior or paint interior walls, we can help. Using tried and tested industry techniques, we will effectively remove any paint from any surface, while preserving the integrity of your brick.
Our team of highly-trained technicians has the professional knowledge to understand different types of paint and how to remove them. They can remove masonry paint, graffiti, oil-based paint, latex paint, and acrylic paint, leaving your brick as good as new.
They are fully OSHA-compliant with the more hazardous paint removal methods, ensuring both their safety and yours.
If you are ready to restore your brick to its natural beauty, contact us to find out how our paint removal service can help you.
Removing paint from brick is notoriously difficult, especially with paints designed for exterior use. There are a variety of methods that can be used, depending on the paint composition and brick condition. Some of these can be hazardous or have the potential to damage the brick, so may be best left to professionals.
