Renovating

Renovating a facade: how to upgrade your house

Torben Schröder

The facade is both the face and the first protective layer of a house. It should therefore always be kept intact. However, it has to withstand a lot of external influences, and will become less attractive and functional over time. The paint will gradually flake off, and cracks will appear in the plaster. The complexity of the repair work needed depends on the type of defect. In this article we explain how you as a homeowner can recognize when something needs to be done and decide which measures to take.

A construction worker kneels on a scaffold and applies new plaster to a house facade.
© Getty Images

In this article

Check the condition of the facade

Something that initially appears quite serious may just need a cosmetic retouch. You should definitely double check before you plan a major facade rehabilitation. This can save you a lot of money and work. Below we list three common methods you can use to easily assess the condition of a facade yourself. You should carry out these tests at least once every five to ten years – if no obvious defects have been found by then.

  • Visual and wipe test: what does the outer shell of the house look like? Are there any holes or cracks? Is it infested with moss or mold? Stroke your hand over the surface. Does the color peel off? Does plaster start trickling down?
  • Knock test: form a first with your hand and tap the surface centimeter by centimeter. You don’t need to hit very hard. If you hear any differences in sound, this may indicate loose plaster.
  • Scratch and adhesive tape test: scratch the surface with a pointed object. If the plaster comes loose, it is no longer stable. Adhesive tape takes the test one step further. Cover the scratched areas with a few strips of tape, then grip the tape tightly and pull it away. Even with this method, nothing should come off the wall.

Renovate or rehabilitate?

These two terms are often used as synonyms, but actually mean something quite different. Renovation usually refers to the optical embellishment of a room or a surface. It involves repairing or replacing worn components. Rehabilitation on the other hand consists of the necessary remediation of structural defects. It may apply to individual areas or entire buildings. It is advisable to consult a specialist when rehabilitation work is required. In this article we will deal mainly with facade renovation.

What types of facade damage are there?

From a slight flaking of paint to extensive slivering of concrete – damage to the facade can be easy to renovate or costly to rehabilitate. We define the different types of damage below:

Soiling

It’s happened to all of us. While out for a walk, we’ve seen houses around us and sometimes asked ourselves “How could they let their house deteriorate like that?” Superficial dirt on the facade is not damage, but you should still do something about this type of visual defect. After you have carried out the above tests and know that the facade is otherwise in good condition, a high-pressure cleaner is sufficient to bring about a significant improvement. Conversely, this means you may also only discover damage after cleaning. For this reason alone, you should always keep your house facade clean.

A man cleans a house facade with a high-pressure cleaner.

A simple test: thorough cleaning with a high-pressure cleaner could be enough to bring new splendor to your facade.

Flaking

This is when you detect particles of paint of various sizes coming off the surface. Hairline cracks also frequently develop. The causes can include a lack of primer coat underneath or a poorly applied primer, an excessively thin topcoat or simply the weather. Moisture can form behind the paint, which then expands in frosty conditions. These flaws are harmless as long as they don’t affect the underlying layers. They can easily be remedied by giving the facade a fresh coat of paint.

Slivering

This is when the plaster starts coming away from the plaster base underneath. Reasons for this can include hollow spots, water penetrating through cracks, and extreme temperature fluctuations. Slivering is no longer merely a blemish – the damage should be rectified as soon as possible, otherwise it may spread to the masonry.

Crack formation

If you discover vertical cracks running up and down the outer shell of your house, the alarm bells should immediately start ringing. If the crack proves to be a dynamic crack, it is a sign that your house is moving. Cracks like this occur at points where different components or materials come together. They are usually very wide and deep and can cause massive structural damage if not treated.

Rectifying facade damage: repaint and replaster

If your facade is suffering from major slivering, cracks and structural defects, you should always consult a specialist in facade rehabilitation. You can find suitable contacts at houzy.ch.

However, you can do the painting and plastering yourself during renovation work – perhaps with the help of a few friends or relatives. Below are some tips to help you.

Painting the facade

If cleaning the facade is not sufficient, but its condition is otherwise acceptable, then a fresh coat of paint is a possibility. If you want to take care of this yourself, there are a few things to pay attention to:

  • Remove dirt and flaking particles. If necessary, help them along a little by carefully scraping off additional layers of paint.
  • If you’re working on an old base, it shouldn’t crumble away. Be sure to rectify small holes and uneven areas.
  • First apply a primer, so that the opaque paint is not absorbed too much.
  • You can paint continuous surfaces all in one go. Start at the windows and in corners.
  • “Less is more” – your paint should not be too thick. It’s best to add more later. Before applying a second coat, however, you should let the initial paint dry completely.
  • Pay attention to the external conditions: don’t paint on particularly hot, cold or wet days.

Important: be very careful when working on the facade. If you don’t have a secure ladder, or if your ladder is too short, then rent a scaffold in a hardware store.

The most important factor when painting is of course the color. Since facade paint is constantly exposed to all sorts of weather conditions, it must be particularly resistant to abrasion. The color tone should match the rest of your house and fit in with the surroundings. We present three types of paint in more detail below.

  • Silicate paint: to apply this type of paint, you will need a mineral base such as lime or cement plaster. Silicate paint is breathable. This means that it can absorb and release air and moisture in a controlled manner. It also has a repellent effect against algae, fungi and mold. In contrast, it is corrosive to the skin, relatively expensive and the color palette is fairly limited.
  • Emulsion paint: this facade paint will adhere to almost any surface. Its pH value is neutral and therefore easily tolerated by human skin. It also evens out small areas of unevenness and doesn’t stain. It is not very expensive. The disadvantage of emulsion paint is that it only resists varmint to a limited extent and is only partially permeable, i.e. less breathable.
  • Lime paint: this is considered to be particularly environmentally friendly due to its natural composition. All its components are biodegradable. It has an anti-mildew effect on account of its high pH value. The big disadvantage is the opacity, which means that several layers of paint are necessary. It is also susceptible to wash-out and fading at high temperatures.
Close-up of a paint roller being used to apply paint to a house facade. The shadow of a painter is visible on the wall.

Special paint is needed to paint the facade of a house.

Replastering a facade

You can easily touch up small cracks and uneven areas yourself. We give you a few useful hints below:

  • Chisel off all hollow-sounding areas of old plaster. They are not firmly attached to the surface underneath.
  • In order to replaster larger surfaces, or even the entire facade, you will need to start by patching up any uneven areas. To do so, you should apply plaster mortar to the corresponding areas with a spatula.
  • Primers exist not only for topcoat paint, but also for plaster. They are known as depth primers. They provide a non-slip surface and a firm attachment to the surface beneath.
  • Work with a two-layer plaster system. The lower layer of plaster usually consists of an adhesive filler, which ensures a consistently absorbent and even surface. You should also incorporate a layer of reinforcement fabric into this adhesive filler. The glass fiber structure of the reinforcement fabric will have a compacting effect. The finishing coat is designed above all to withstand mechanical influences.

Next, we will introduce you to different types of plaster:

  • Mineral: this factory-dry mortar consists of high-quality mineral raw materials such as limestone, sand, marble and quartz as well as mineral binders such as lime and cement. Mineral plaster is very durable, regulates moisture well and is relatively inexpensive. However, it is not particularly resistant.
  • Synthetic resin: also called dispersion plaster, its advantages are resistance and transformability. It is good at adapting to the surfaces on which it is applied and to climatic conditions. It is virtually immune to extreme cold, excessive heat and humidity. Cracks in synthetic resin plaster are almost impossible. However, the low diffusion capacity is also a disadvantage, as the masonry gets little air and there is a greater risk of mold growth.
  • Silicone resin: silicone resin plaster is a synthetic resin plaster of superior quality. Due to its low surface tension, it is very water resistant and doesn’t give harmful organisms such as fungi, moss, algae and lichens a chance to develop. The more silicone it contains, the higher the quality. It costs about twice as much as mineral plaster.
  • Silicate: silicate consists of inorganic particles, also called silicate, and is a compromise between two worlds of plaster: it combines the qualities of breathable types of plaster such as mineral plaster with the robust capacities of synthetic resin products. Silicate plaster usually contains a small amount of emulsion paint, which is why other materials adhere to it particularly well. Just as with silicate paint, silicate plaster requires a mineral base.

Facade insulation and cladding

Depending on the extent of the renovation or rehabilitation work, it may be worth carrying out other work at the same time. The house facade is also always a factor that determines the energy standard of your house. If there is no thermal insulation, or if the insulation is insufficient, this is your chance to make improvements.

To enhance the outer appearance of the facade, you can also cover it with cladding. A rustic wood look, a robust stone coating, a sophisticated metallic membrane – there are many options open in terms of material, color and design.

Conclusion: a good result in a few simple steps

You can take care of a simple facade renovation yourself: a fresh coat of paint or new layer of plaster will bring new splendor to the exterior of your house. If you discover structural damage to the masonry, a comprehensive facade rehabilitation may be necessary. This is when to call in a specialist.

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