A Guide To Waterproofing Brick Walls

Waterproofing brick walls


Why Should You Waterproof Your Brick Walls?


Whether your house is a new build or a historical building, waterproofing your home is essential for maintaining its integrity, reducing the risk of damp & increasing its energy efficiency.


Leaving exterior walls untreated can lead to increased moisture levels within the property, which in turn can lead to penetrating damp & irreparable damage.


Large scale repairs of damp damaged properties can be extremely expensive, not to mention the health risks to the occupants of heavily moisture exposed buildings.


Is this exposure to moisture inevitable? No, waterproof paints and coatings such as Emperor Paint prevent this moisture intrusion, keeping properties warm & dry.


How Do Brick Waterproofing Treatments Work?


Innovative formulations such as Emperor Masonry Paint & Masonry Creme line the pores of substrates, waterproofing the exterior walls of the property from moisture penetrating into the interior of the house.


It does this using the latest nano-technology by chemically bonding to the surface it is applied to, penetrating deep into the substrate.


This creates a super hydrophobic surface on the building material, meaning water is repelled off from the surface rather than being absorbed. This water repellence is called the beading effect or 'lotus effect', named after the lotus leaf which shares similar waterproof properties to Emperor Paint.



The lotus effect


While the waterproofing the surface of the material, Emperor Paint does not seal the pores, allowing them the breathe and letting moisture escape from inside the property. Highly breathable masonry paint like Emperor Masonry Paint are essential for reducing penetrating damp and protecting properties from moisture. The combination of water repellence and high breathability is what makes this the best masonry paint to use.


What You Will Need


Before you start the process of waterproofing exterior brick walls, make sure you have the right tools for the job. This will make the application a quicker & smoother process.


You will need:

  • Masonry roller
  • Paint tray
  • 4 inch brush
  • Dust brush
  • Sand paper
  • Dust sheets
  • Window film
  • Masking tape
  • Emperor Masonry Paint or Masonry Creme


Preparing The Surface


Ensuring that the surface is clean ready for painting is essential for ensuring the most effective application and to ensure that the waterproofing properties of the paint are maximised.


1. There may be signs of a white powdery substance on the brickwork. This is called 'efflorescence' which is caused by water ingress. Remove this before continuing the painting process. In some cases, using a dry, stiff brush can remove the salt deposits from surface of smooth surfaces. 

Read the full guide to removing efflorescence. 


2. Assess the brick walls for any signs of cracks or damage. If there are any defects in the brickwork, ensure you patch these before painting. Use exterior filler to repair any cracks as the brick wall will not be effectively waterproofed.


3. Brush off any visible dirt with a dust brush.


4. If there is any peeling on the brick from previous paint, sand this down using sandpaper. This will ensure the most optimal finish once painted.


5. While ensuring the surface is dry, apply the Emperor Paint Exterior Masonry Cleaner. This removes moss and algae while disinfecting, leaving the surface ready to prime and paint.


6. Allow it to dry and be absorbed into the surface of the building for a minimum of 2 hours. If you are intending to use Emperor Masonry Creme, wash the surface after two hours with a hose to remove any residue and then leave to dry again. This is not necessary if you are intending to use Emperor Masonry Paint as the coloured paint will cover any residue.


Tips for waterproofing exterior brick walls


7. If using the coloured Emperor Masonry Paint, ensure that the Emperor Paint Primer is applied before the paint so that it is not absorbed into the brick or render of the building. This is not required if you are using Emperor Masonry Creme. Ensure that the Primer is completely dry before painting. This will take 3–5 hours at 20°C. Applying the Primer is essential for the waterproof masonry paint to adhere to the surface correctly. If this step is missed, the brick walls will not be waterproofed effectively.


8. Apply masking tape along any the edges of areas you are not painting, such as doors and windows.


9. Set the dust sheets underneath the area you will be painting to reduce the risk of paint splashing on to other surfaces.


Applying The Waterproofing Treatment


Ensure conditions are dry before beginning painting, this is required to ensure the waterproof paint can correctly cure into the exterior walls. Furthermore when the temperature is below 5°C Emperor Paint should not be applied.


Emperor Paint offer two brick waterproofing products; a coloured two coat Masonry Paint and a clear one coat Masonry Creme. Make sure you to leave as much time as possible when using the Masonry Paint to ensure time for the second coating.


1. Apply the product to the edges using a brush first.


2. When painting on a ladder, pour a small amount of paint into an easy to handle container to make application while on the ladder not only easier but safer. 


2. In metre square sections, apply the paint using a paint roller, ensuring that the coverage is even. The optimal coverage is approximately 5–6m² per litre for the Masonry Paint and 3-5m² per litre for the Masonry Creme. 


3. Once applied, allow the Masonry Paint to completely dry before applying a second coating. This should take approximately 2 hours, but may take longer. Emperor Masonry Creme is a one-coat system, so once applied leave to cure into the brick. Do not attempt to brush the product into the brick as it must be allowed to soak into the brick as it cures.

  Quick tips for waterproofing exterior brick walls


Allow To Cure For 48 hours


The waterproof ability of the treatments requires a curing process to allow the technology to fully line the pores of the surface.


While the coatings will still be waterproof while curing, the full beading ability of the products will not be present until completely cured.


Waterproofing Brick Walls - FAQ's


Q. Can you apply brick waterproofing products onto previously painted surfaces?


A. Yes, you can apply Emperor Masonry Paint over previously painted surfaces. You can not apply the clear Masonry Creme on a painted surface. Remove this layer of paint if you wish to use the product, as this is designed for untreated absorbent mineral surfaces such as brick, concrete & stone.


Q. Does the products dry matt or shiny?


A. Emperor Masonry Paint dries with a matt finish while Emperor Masonry Creme will penetrate into the substrate of the masonry and dry without altering the appearance of the masonry. This is in contrast to brick sealers that create a film on brick, often leaving a sheen on the surface rather than offering a natural look.


Q. How often will I need to re-apply masonry paint?


A. The life expectancy of masonry paints can vary. Emperor Paint products have a lifetime expectancy of over 25 years as shown through independent tests conducted by UKAS accredited laboratory Lucideon. In a 25-year accelerated weathering test, Emperor Paint & Masonry Creme showed no signs of reduced performance or aesthetic change. This means that the waterproof masonry paints could far exceed 25 years.


Q. When is the best time to apply brick waterproofing treatments?


A. As previously mentioned, you should not apply masonry paint in temperatures below 5°C or in wet conditions as the surface must be completely dry to be effectively waterproofed. This means that it is not ideal to apply masonry paint in winter months. Try and allocate a period where no rain is forecast and where you will have enough time to apply two-coats, if using a two-coat masonry paint.


Q. How much masonry paint will I need?


A. It is essential to check the coverage of the masonry paint you are using before beginning the painting process. We recommend that you calculate this so you are guaranteed to have enough paint, as this will ensure that the full project can be completed evenly at the same time. Painting patches on different days will lead to an unsightly finish to your masonry. We've put together a handy tubs of paint matrix, which will allow you to estimate the number of paint tubs you'll need to paint your house with Emperor Paint so you can work out exactly how much you will need to complete the job.

Calculate how many tubs you will need here.


Q. How much do brick waterproofing treatments cost?


A. The price of waterproofing treatments can vary depending on the longevity and quality of the product. As the most advanced masonry paint on the market, Emperor Paint offers unrivalled value for money. Due to the one coat application of Emperor Masonry Creme, a 10 litres tub is approximately enough to fully coat a mid-sized terraced house.


Not only does the masonry paint offer value for money in the short-term, it offers long-term value for money from significantly reduced maintenance costs. Whereas a less advanced masonry paint will need recoating after as little as 5 years, Emperor Masonry Paint will not peel or flake for a minimum of 25 years. Furthermore, applying a waterproof masonry paint will protect you from extremely costly damp prevention and repair.


Q. What is the difference between anti-damp paint & brick waterproofing treatments?


A. Damp proof paint, otherwise known as anti-condensation paint is a form of interior emulsion that prevents mould growth by reducing the amount of condensation that gathers on interior walls. It is commonly used in high moisture rooms such as bathrooms & kitchens. Brick waterproofing treatments while they can help reduce damp, are external products. They prevent penetrating damp which is an external form of moisture than soaks into absorbent bricks through into the internal wall. Understanding what is causing your damp problems is essential for knowing what type of product to use. 


Sit back and relax


Once applied, you can have the peace of mind that your home is protected from damp, damage & decay from water intrusion.


Make sure you send us a photo of your finished project on social media using the hashtag #MyEmperorProject. We love to hear about your projects and share the very best for all to see!


Alternatively you can send us your finished brick waterproofing projects to info@emperorpaint.co.uk.


Waterproofing your exterior brick walls couldn't be easier. Emperor Paint is available in a coloured Masonry Paint or clear coat Masonry Creme, so no matter whether you are looking for a re-vamp or to maintain the natural beauty of your bricks, there is a waterproof coating for everyone.


Exterior walls waterproofed


Hopefully this should have answered any questions you had regarding waterproofing brick walls. If you have more questions, we are here to help with our full technical support from our in-house team of experts. Whether your suffering for penetrating damp and want to know if the products can help you or want to find out more information about our brick waterproofing treatments, they are on hand to help. Talk to one of our experts today or find out more about Emperor Paint products