Factors to Consider when Painting Brickwork
At Modular Clay Products, we take pride in sourcing UK bricks (and international bricks) through our trusted network of worldwide brick manufacturing experts. Brick suppliers and brick manufacturers work collaboratively to produce aesthetically attractive, solid and reliable brickwork that meets their customers’ expectations and needs. Any architect who comes to us can rest assured that their materials are in good hands.
Put simply, we take any request seriously, working hard to source the best quality bricks that tick all the boxes, from brick colour and brick texture to their size, dimensions and shape. All of these elements impact how the brick will look en masse when the commercial building is assembled.
Therefore, the concept of painting bricks, ideally, shouldn’t cross your mind. However, it is a query we’re faced with from time to time. So, although painting brickwork shouldn’t be necessary, we’ve created this short guide for any times that you do consider it.
Why Paint Bricks?
When working with Modular Clay Products, you will invariably end up with high-quality clay bricks in the exact colour, dimension and texture you require. In certain circumstances, however, painting brick products may be necessary for matching purposes. For example, if planners need to maintain a local aesthetic, then painting bricks may be required.
Historically speaking, bricks were painted to mask any damaged or unsuitable products used in structural alteration or extension work. New build properties are good examples of where painting brick poses an issue; they’re often painted as soon as they’re constructed, frequently overlapping with the time taken for bricks to dry. Usually, this results in the erected exterior brick walls becoming quickly discoloured or stained, thanks to the mineral and soluble material migrating to the surface.
Surface treatments such as painting may cause damage to the facings; therefore, painting is not always indicative of proper UK brick construction practices. This is why you, as an architect, should pay close attention to the following factors if you have considered painting your finished clay facing bricks.
Types of Bricks in the UK
When choosing the best brick type for your commercial brickwork, for adequate paint adherence, you should bear the following in mind:
Moisture content
Excessive moisture content will affect the adhesion of most paint types. The moisture occasionally leads to blistering and flaking, while simultaneously providing space for mould and algae to grow.
Many coatings will fail or be met with issues until the brick’s moisture content has substantially dried out. Even in warmer conditions, drying can take a long time. To check the moisture levels, it’s best to use an electronic meter.
Brick efflorescence
We have previously explored the topic of efflorescence on bricks, so for more information, we recommend revisiting this blog. However, to summarise, salt and minerals within bricks can escape as moisture leaves, forming a white, powdery surface texture.
Efflorescence can pass through water-based paints over time, but applying paint is not recommended even if you’re using a water-permeable treatment.
Porosity
Bricks can vary in their porosity depending on their manufacturing process and their density and aggregate used. Even dense bricks are porous enough to provide good adhesion for paint. However, if the bricks are located in exposed environments, you should opt for more protective solutions.
Brick Selection
Hopefully, it’s now clear that bricks should be structurally sound and consistent, not just visually but in terms of their physical properties. This is vital for achieving a uniform appearance throughout the exterior, hence why bricks of a similar absorption rate, strength and shape should be used.
Some common types of bricks to use may impact whether the paint should be applied. A few examples are listed below:
- Engineering bricks have a low absorption rate and should ideally not be painted.
- Common bricks aren’t ideal for exposed brick facades anyway, whether under paint or not.
- Stock bricks are solid and reliable but may often not allow the paint to adhere to them appropriately.
- Clay bricks are often filled with soluble salts and materials, making them prime targets for efflorescence if not treated or manufactured properly.