Water Based Paint Problems and Solutions Pt 1 Chalk & Algae

South African has a very unique climate; therefore there are certain paint problems that are specific to it. In, the next few articles we will address some of these problems and how to remedy them. In this article we will start with problems chalk and algae.


Possible Causes..

  • Algae can grow on surfaces that are continually damp and dirty and receive no sunlight.
  • Insufficient fungicide/ algaecide in the paint can also worsen the situation.
  • Areas that have had previous mould, may have also been painted over.
  • Reusing opened containers that have received contamination from application transfer and or storage conditions.
  • failure to prime a bare wood surface before painting.


  • to distinguish, firstly if the contaminant is fungus/algae or dirt, drop a few drops of household bleach onto the designated area and see if the discoloured areas disappears. if it does then it’s probably fungus/algae.
  • check for any sources of moisture eg leaks, sealing or ventilation. Fix them.
  • apply a surface sterilizer/fungicidal wash (a diluted household bleach solution – 1 part bleach>3 parts water can also be used) Leaving on for 20 minutes, applying more as it dries. Then scrub and rinse thoroughly. Remember to wear rubber gloves and eye protection while doing so.
  • High pressure washing is a solution to fungus/algae (remember to rinse and residue and allow to dry again before applying any recommended paint)
  • prime the surface with a water based primer.
  • apply a premium exterior water based paint that is protected with a dry film biocide.



Chalking is the formation of a white, chalky powder on the surface of a weathered coating, it happens when the binder within the paint is broken down periodically due to weather conditions, UV rays and moisture exposure, the binder then releases the pigment articles within the paint, what you see as the white chalky power is consequently the broken down binder and released pigment particles. Nearly all paints will show some evidence of chalking over time, when they are subject to outdoor exposure. This slow erosion is much more preferable than cracking or flaking and once the chalk is removed the area is desirable again for painting.

You can identify chalking by rubbing the surface of the affected area with a damp cloth (or even dragging your hand) which results in a light deposit to the cloth and the restoration of the colour to the cleaned surface.

excessive chalking is not desired, because it can run down onto the underlying structure and deface the appearance of the surface. It can lighten the colour of your paint or erode your paint film resulting in a loss of protection to the substrate.

Possible causes..

  • using an interior paint quality for outdoors use ie enamel paints or lower gloss level acrylics.
  • poor surface preparation and a failure to remove the poorly bound surface before painting – paint needs to adhere to a sound surface.
  • Using a low grade paint comprising of a low binder and high pigment loading.
  • use of an interior paint for an exterior application.
  • not adequately sealing a porous surface.
  • spreading a coat too thin.
  • nearly all paints will show chalking over time as subjected to outdoor exposure – most south african medium quality paints are in the medium to high PVC range, and chalking can be expected within 3-4 years.


Chalk needs to be removed before repainting – it is is in the same category as dust or dirt.

  • Rub the painted surface with a finger or dark cloth to determine the degree of chalking.
  • high pressure cleaning is a common surface preparation method, and can be used to clean chalking.
  • scrub with a stiff brush . Rinse thoroughly and allow to dry. Rub the surface with your finger to see if any chalk residue remains. Repeat the cleaning process if powder is still present. If chalk persists, recoat with Alkali Resistant/plaster Primer or Bonding Liquid and coat with appropriate quality top coat. If little or no chalk remains, and the old paint is in good condition, then no priming is necessary.


Importance of High Pressure Washing

We strongly advocate High Pressure cleaning, High pressure Cleaners are awesome pieces of equipment to have because they can cut through grime in no time (yes, that’s right I just made a little rhyme) making cleaning your house or industrial area that much easier, and more enjoyable.

They are a necessary piece of equipment when coming to the ‘painting-your-building’ process, and we absolutely love them. Here’s why:

What is High Pressure cleaning?

High Pressure Cleaning is the use of high-pressure water spray to remove loose paint, mold, mildew, grime, dust, mud, chewing gum and dirt from surfaces and objects such as buildings, vehicles and concrete surfaces (in this case residential houses or industrial properties). A pressure washer is really less complicated than it sounds. It’s really just a water pump powered by an electric motor. The washer takes in water from a tap, the pump accelerates the water to high pressure, and then squirts it from a hose at speed through a trigger gun.

Why Pressure Jets get Things Cleaner?

in fact, did you know there’s a good scientific reason why water gets things clean so productively? What happens, is that the water molecules have a bit of an electrical polarity (one end is positively charged and the other end is negatively charged), this is the reason it sticks to things so nicely. Of course, you can add detergent to the water to help it break down the grime and grease and help you clean things even further. But what happens when detergent doesn’t work? there are some forms of ground-on dirt that just won’t go away. This is when high pressure cleaning comes in handy.

high pressure cleaning uses a very narrow jet of hot or cold water blast the tough dirt away. the water is travelling very fast, it hits the dirty surface with a high kinetic energy, knocking dirt and dust away like a constant rain of tiny hammer blows. But you’re afraid it might damage your surfaces? No, even though it boasts a great amount of pressure, it’s still only water, and is therefore kind to most hard surfaces. Although, it’s still a good idea to test the jet on a less conspicuous area before you start working for real.

Why is High Pressure Cleaning Important?

Hydro washing is important, because it removes old and layered peeling paint coatings, it removes mold and mildew that has developed due to weather conditions, it exposes a lot of defects ie cracks, bad plaster and damp which is disguised by old paint. removes chemicals, oils and other elements that adhere to surfaces, it removes dirt and mold which over time can erode building materials.

Pressure Washing is absolutely necessary for Surface Preparation.

If repairs re needed to surfaces, high pressure cleaning clears the surfaces properly before coatings are applied. By eliminating unwanted elements and chemicals new applications can sufficiently adhere to surfaces. This provides superior adherence of coatings, finer finish coatings and a maximum duration of product applied to surfaces.

Using a High Pressure Cleaner Correctly?

High pressure is not necessary in every situation. Using high pressure cleaning on the wrong elements of your house, like PVC or soft wood can actually damage your house and leave it unsightly. An experienced high pressure cleaner will know when to use high pressure, and when to turn down the nozzle. Good cleaners should rely on the right amount of pressure, and good cleaning to get the job done. Which will result in your home looking thoroughly clean and undamaged.

So, if you’re going to ‘vote’ High Pressure cleaning, don’t just choose any old Joe, or fool. Make sure you choose a trusted professional, and somebody who knows what they’re talking about.

What is the Difference between Structural and Non-Structural Cracks

You know what it’s like? You walk outside your home, take a look at that seemingly harmless crack on your wall, and then all at once on your lovely summer’s day, you start to worry.  Don’t worry, were here to help. While it is true that that minor cracks can turn into bigger cracks to threaten the structural integrity of your home, and that every crack should be taken a look at by a professional, there are differences between structural and non-structural cracks that you can view here below..


These are small less that 3mm in diameter cracks, that do not at the moment threaten the integrity of your home. They appear in your foundation.  Weather conditions, temperature changes and moisture content naturally cause your foundation to experience these cracks.



Some of the factors that cause non-structural cracks are:

  • Creep damage
  • Shifting foundations
  • Hydrostatic pressure
  • Settlement
  • Vegetation or trees

Like we said before, not all cracks are initially threats to your home’s structural integrity, nevertheless they should be monitored and treated very carefully off the get go, as water can seep into these cracks and start to erode your homes inner concrete.


There are a number of different issues that cause structural cracks, like swollen soil, poor soil bearing, poor construction sites and overloading.  You can tell if you have structural cracks, because you will have problems on the inside of your home, like sloping floors and windows sticking when you close them.

Generally, structural cracks appear wider than 3mm in length. They can appear in the wall beams, foundation walls or slabs. And they usually extend to the upper floor of your house. They can be vertical, horizontal, diagonal or run like a staircase.

How to Address Structural and Non-Structural Cracks.

Non-structural cracks should be monitored and taken care of so they don’t get worse, they are usually repaired with an injection of a sealant resin, this resin protects your foundation from future leaks and prevents the problem from worsening.

There are a number of methods that can be used to fix structural cracks:

  • Injecting the crack with urethane to permanently seal it.
  • Install carbon fiber strips to damaged walls.
  • Using resistance and helical piers to level sinking and settling foundations

Paint Doctor uses a number of professional and efficient solutions to get your home back to the state it should be in, contact us for further support and advice.

How to pick paint colours for the outside of your home.

Everybody wants a great looking house, and you can imagine it in your head ‘the way the colours fly off the palette!’, but real life can be a different game sometimes.

Do you ever remember walking down the street as a teenager and screaming in laughter at a crazy pink house?

Or seeing a house, so dim-drab grey as you rode past it it just knocked you into the cold recessions of your consciousness?

There are a number of problems to deal with when painting your house in a neighbourhood, being too bland or colourful or but just a few.

These are not the only problems; there are other hurdles as well. Like landscaping, hardscaping and roofing, not to mention homeowners association guidelines or not stepping out onto your pavement and getting that ugly look from Goerge your (not so funny) neighbour because you painted your house the wrong a colour that doesn’t suit theirs or entertain the neighbourhood’s taste.

Where do we get home from here?

There are a few simple rules to observe.

The truth is painting your house the right colour will not only bring out its best characteristics, but will also hide its design flaws and elevate its market value.

Three in One

Generally a paint scheme has three major shades: field, which dominates (most of what you see at first when you look from the street), accent, which brings all the little areas of your house to life, like doors, shutters and etc. And your trim, which highlights your roof edging, railings, window and door casing.

Your field colour should dominate your choice of accent, and trim.

Are you wanting your house to look more prominent on the street? Then you want to go with painting it a light colour. Light colours can add a sense of size and dignity to your house. There’s a reason why many grand estates are painted white.




Do you want more drama?

Then you want to paint your house a darker colour. Darker colours will shrink your house, but give it a stronger, more solid appearance.




Your trim colour is also very important.

Usually, you want to paint your trim a different colour, and a colour that contrasts strongly with the field colour. But this is not always the case, and in some instances people do paint their trim colour the same as the field colour but sometimes, this is not to work and it gives the house a a rather ‘unfinished’ look. Your safest bet is most always keeping the trim lighter than the field.

Although for stunning little effects:

You can either (a) touch your light field with a dark trim, giving it an ‘eyeliner’ kind of effect on your home.

Or (b) paint your light field with a dark trim giving your windows a ‘picture frame’ effect and making them look like they were hung up. Also very visual.

So, what should we do with the accent colours?

Accent colours can be fresh and exciting. Feel free to go bold with them, but don’t go overboard.

Remember that, a door, a shutter or a window frame painted in of those fresh and exciting colours can look very enticing, but not so much when you start to extend it to all the other little places that shouldn’t have it. Remember when your little one drew something lovely in that bright colour, and you thought it was just too adorable? But then they started to draw it on the walls, the kitchen and all the other very valuable surfaces that you call a home.

Good places for accent colours, are doors, shutters and window frames.


What are the most important things to remember when choosing a colour scheme?


Whether you have a Victorian, Tuscan or Modern style home, it is good advice to generally observe the style and era guidelines. This is not to say, that every house shouldn’t have its own personality, but not all houses look good in ‘party dress’ all the time.

If you’re a little confused about this, remember that many paint dealers offer a great collection of accurate colour combinations. There are also excellent professional services that specialise in this area, that you can call on anytime.

Neighbourhood awareness is also a big thing. Remember that your neighbourhood, in some instances will have a certain style and a cultural feel. It might be a good idea just to adopt a tip or two, from that. Before your neighbours come running down the driveway with long sticks in their hands. In other cases you might have upset your neighbourhood homeowner’s association rules, and guidelines. Not every neighbourhood has one, but you would do your best just to check it out.

Look for the unchangeable.

Many people don’t take into consideration certain foundations of their home when painting, and don’t think they will play a part in the colour, but they do. For instance: Have you ever thought about the effect the colour of your roof would have on your painting your house? Do you plan to paint your roof over, again? Or are you just going to keep it the same colour? What about your driveway?  Do you have a brick or a stone driveway? What colour are those bricks or stones? What kind of property do you have? Are there a lot of trees and rocks on your property? Have you taken those into consideration? Nature can be a great informant to your palette. You may find underlying tones undertones of brown and green.

Try it first!

Painting the outside of your house is a bigger deal than painting a room, so you will want to be extra diligent with the colours you pick, the way a paint colour looks on a chip inside a store varies greatly from the way it will look in the natural light or an a large surface.

Painted on large surfaces paint begins to look lighter, natural light also changes the way paint colour looks. Chances are you’ll need a much darker colour than the one you first picked.

Get a colour wheel and choose a few colour schemes, then buy a quart of each colour – and a quart of several other colours that are nearby on the colour strips (due to above reasons). Buy quarts before you buy gallons. Most paint stores sell quarts of paint at reasonable prices so you can try out several colours or colour combinations before you commit to a scheme. Find an inconspicuous area (the larger the better) area of your house first, and try them out. Let them sit in different times of the day and night (also in varying weather conditions) so you can see how they look.

Extra Tips

  • Contrasting colours can be nice, and this can draw attention to architectural detail, but at times can clash so badly that it actually retracts from the detail. Be flexible and be willing to experiment, but remember that staying within one colour family is the safest. Instead of using a different accent colour, why not use a lighter or darker shade of field colour?
  • You can find inspiration in the inside of your home for a colour scheme too. Look at your living room and your furnishings. Harmonizing the inside and outside of your home can be a great way to find a match that works.
  • Sometimes flying in the face of the past can be just what you need. Painting your old architectural a house a bright and vivid colour can bring effective and astonishing results to detail. Check out older houses who have done this for the cue..
  • The more intense a colour is the more likely it is to fade, sometimes even change colour altogether. On the other hand, dark colours absorb more heat and suffer more moisture than light colours. These pose more of a maintenance threat. But they don’t show dirt so easily. Think about how you can add longevity to colours when choosing them?

No matter how you feel about picking paint colours, there is always a mass of help out there. Most of paint stores have pre-selected colour palettes arranged by style and colour range that specify just the right, necessary field, trim and accent. Some paint stores even have online programs that show you how to pick the right colour. Visit your local friendly paint store today for top advice!

We look forward to seeing you there..

Hues & Spaces..

Have you ever walked into a room and felt happiness or joy? And then shifted into another space and felt a sense of uneasiness, or dread. Do certain things on the shopping shelf attract you, and other certain things lend you no interest? Do you know what this is the product of? Colour. Whether houses or shopping products in shops – colour makes up for the vast majority of our responses, even if we don’t seem to know it.

Colour Psychology is a term commonly used today to describe the effects of colour on us, be the effects subtle and in-definitive as they may be, though they are there: significant and strong as bold colour can be. Think about it, when you go for a walk late in the afternoon and see the shifting pastel colours of all the green of the trees around you, you feel a certain way? Or the deep red ruddy colour of the soil that took you there? Colours are important to us no matter where we may be, and there’s a reason that we strive to have them so close to us, whether in our home lives or in the businesses we work in.

If you’re not sure about what colours to pick for your home, here we’ll provide ten tips for you:

Baby Steps

Try and look at this process as an adventure, as a fun journey you’re going on. You don’t have to begin big, or in very important rooms in your house. You can even have your children try with you, start smaller in less pronounced areas i.e. a small hall, an area between rooms or an accent wall. Pick an area that’s quick to do so you can see your results even quicker. If you’re not happy with the results, you can easily change them.

Which colour do I pick to get started you may ask? That’s easy. Just look around you. Your house will be full of colours you might not have seen, there are colours in your furniture, your rugs and artwork or even your dishes may inspire you to choose a main colour. Again, have fun with the process.

What do you want to feel when you walk into a room?

 Different colours are for different rooms. But that’s all up to your palette of course. Do you want your bedroom to feel tranquil and subduing or exciting and stirring?  Soft, cool colours and neutrals usually create a quieter feeling while stronger colours are for drama.

How do you want to have dinner? Do you want to come home after a hard day’s work, and have a quieter dinner as you ponder over the trickling pond outside? In this case, you want to paint your dining room cooler colours, like deep blue greens and neutrals which will give you a more formal balance. Or are you the type that likes to entertain; popping champagne bottles and swinging hors d’oeuvres everywhere, in which case you’d like to go for something more electric and stimulating; like brighter colours that contribute to a more social atmosphere. Colours like this are usually warmer, and more contrasting.


How do you want your kids to play, and feel? Do you want to bring more order and peace into their lives? Or do you want to contribute to the little critters being terrifying little livewires? Note of caution though: using colours that are overly bright, and using them too much may contribute to much unrest and irritability in your children’s consciousnesses and minds. You may want to keep it in check.

Ask yourself, what is the most important role this colour will play in this room?

What does the light have to say about it?

The light speaks. It says different things about different colours. If it could, it would say hello to you:

  • When you allow, the warm natural daylight to shine on you it will bring out the truest colour.
  • Unnatural light, i.e. warming for effect, will bring out warmer tones and yellows.
  • This is not about your children dancing in the raves: fluorescent lighting will cast a sharper blue tone.

So, what can we learn from this?

You live in your house all day, and you might not be able to handle it if all your walls or a wall next to a large window were painted with a strong colour (unless you were the mad hatter). But, on the other hand if you would want to draw attention to something then having that colour on an indirect wall like an accent wall, could really prove valuable while you splash a little bit of indirect light on it. Capisce?

Tip: A very handy thing to do is select three swabs of the colour you (think you)) want, one in the middle, one lighter, and one darker. Put them next to a window and a dark corner and look at them during different times of the day and night, then make your decision.

Dr. Colour

When undertaking a new venture, it invariably helps to understand the terminology:

Here’s what different colour terminology means..

  • When referring to a colour i.e. red/blue you would call it a Hue
  • Determining how light or dark that colour is, would be called a Value
  • If you want to know how dominant the Hue is, you would call that Saturation (going from red to pink the red Hue becomes less dominant)
  • Terming, how brilliant the colour is called Intensity. Pure colours such as red are more intense than the combined colours such as yellow-green. A stronger intense colour usually has a more dominant hue.

If you want your space to be busier, think of using colours that are stronger, and more intense. This will even work if you want a real light coloured room; you should choose to use colours that are more saturated than off-white or light pastel. If you are going to use a very light colour on each and every surface in a room, its inevitably bound to feel bright and stark. When using two or more medium-light closely related pastel colours you will get a luminous effect.

See what colour works for you?

There are many ways to test your colour zone, you could grab different kinds of boards, perhaps go to that back wall of your house that you never use? You could even perhaps paint your partners car? Bring your wild ideas out? Otherwise you’ll never know what’s for you or not. You could splash-dab brilliant and vivid colours like cherry red or ice-blue, or you could go a softer tone for say, ivory, chocolate or taupe as your main or accent colours. If you want to add a sense of drama in the room, you could paint a stronger colour on the ceiling. Another nifty trick is to tint the ceiling; this dramatically changes the whole look of a room.

The decoration of life!

 You feel that a wall is too boring, lifeless or flat? You can easily spring it back up, with interesting decorations that would make Spring smile. Sometimes it’s just breaking the colour, and other times it’s something a little less subtle like adding some visual incarnations. To add some colour you could incorporate techniques like colour washing, rag rolling or sponging. For visual incarnations you could use techniques like burnished mineral or metal finishes, or layered colour glass. Some examples of softly reflective metals are mica, copper, pewter, bronze and, of course, antiqued silver and gold.

 Flow like a river..

Imagine your house was like on big piece of artwork, it would be important for one colour to compliment the next would it not? And for all the colours to be in synergy. This is what you want to do. You want to stand in one room, and imagine the colours you are going to use on the walls, then move into the next room and imagine the colours you are going to use in there? You want to make sure that all the colours create a harmony, and that there is a continued flow throughout the house.

Tip: You may even use one or two colours throughout the whole house, and then just throw in a few additional accent colours; this way you get great continuity but allow the different rooms to retain their different personalities, respectively.

The relationship between colour and decorative elements.

Colour can do interesting things; it’s more effective than we think. In this way, it has great effect on special perception of its surroundings and the as well to the balance it brings to the pieces of artwork therein.

For instance, if you want a room to appear smaller, you paint it up with cooler colours. If you want a room to appear larger, you paint it with brighter, warmer colours. Balance is also another important element of colour, a coolly coloured room would not hold a bombastic, bold centre piece of art well.

Let the colour wheel guide you..

How do you know which colours work together or not? On a grand scale you want your colours to work together like the different peaks of a mountain in a mountain range picture. This is not always easy for an amateur.  A great way to test your palate, and get your knowledge going is a colour wheel. This will easily lend you it’s knowledge as to which colours go together and to which do not. Walk through the house and have fun with it. Imagining blue line upon blue and red upon red. This is also great for discovering which colours you like and which you do not.

Tip: you can choose the colour combinations at your discretion, but there are a few that generally work best.

  • Blue and white or yellow and green looks dazzling in a kitchen.
  • Red and black creates a very formal dining room experience.
  • If you’re the Guru, the type to have a library, chocolate brown and camel or dark green and navy blue go well together.
  • Some extra snippets: burgundy and khaki, navy and khaki, or dark green and khaki look enticing together. Otherwise greys and blues always look great together like dashing prince and princess in ballroom apparel.

Singular can be boring?

Are you looking at your walls and trims, and thinking that one colour is too one dimensional? There are two options here:

  • You could create play in one colour group by painting up different variations of a colour in that colour family, or
  • You could use different tricks or techniques in one colour group ie different finishes..

To compliment your main colours you can throw in accent colours. More towards reds to be warmer, more towards blues to be cooler. If you want to be louder, make sure your colours are on the brighter side. If you want a bit of a quieter tone, make sure things are on the duller side. For instance, you could use white or off-white on a trim to create a wonderful accent when playing with a monochromatic theme.

Let the shine speak for itself.

Just the same way your Mom spun you different versions of different stories in the world when growing up, so you’d be surprised how many things can have a different look just by adding a different spin on them. Let’s say, you’d walk into one room and see the paint on the walls is one colour, but the trims are looking a different colour? Upon closer inspection you see that they’re both the same colour. It might be that you used a more, matte and less reflective look on the walls, but a more shiny and glossy finish on the trims? Giving them alternate significance and meanings, but letting them remain both perfectly cohesive.

A quiet word about bold colours

Bold colours are very attractive. They are often the flavour of the season. The trick is to reckon whether you can look at that bold colour every day, all day? You will most likely grow tired of that busy space. If you want to incorporate a really strong colour like that, you might want to think of using it as an accent colour.

This does not mean that a neutral colour scheme is always mandatory, and appropriate. It depends on the house, the location, the architecture, and the personality of the homeowner. It’s about trying to keep a balance. An entire neutral house can be boring.


Some of this advice may seem daunting, ultimately you should follow your heart. If you love a colour and have tested it in the right place you should use it.