In September, the house facade usually still looks fine. Hardly anyone looks too closely, and the narrow crack above the patio seems harmless anyway, half-hidden by the bush in front of it. By spring, however, in the worst-case scenario, it has developed into a chipped area of several square meters, and suddenly there's scaffolding around the house. Nothing particularly dramatic actually happened in between: just rain, cold, and many nights below freezing.
That's precisely why it's worth taking a look at your facade now, while temperatures are still mild. Autumn offers a good opportunity to assess the condition of the surface and identify areas where water is seeping in. Minor damage can still be repaired with minimal effort at this time. Therefore, anyone wanting to winterize their facade shouldn't wait for the first frost.
You're not quite sure what to look out for? MVM AG We will gladly assess the condition of your facade on site.
The most important information about your facade check:
Three findings are crucial: cracks of approximately 0,3 millimeters or more, voids behind an intact surface, and open connections at windows, the roof, and the foundation. Water penetrates precisely these areas, freezes, and damages the plaster. Such areas must be sealed before the first frost. This is possible as long as the air and substrate temperature are at least five degrees Celsius, even during the drying process. This leaves only a few weeks, and now is the perfect time to call in a specialist company.
What does winter do to a damaged facade?
As long as the surface remains closed, a facade protects the masonry from driving rain and temperature fluctuations. If it is open at any point, water penetrates and cannot quickly escape. In summer it dries out again, but from October onwards this drying capacity is lacking. Then the same cycle repeats itself throughout the winter:
- Water penetrates through cracks and open connections.
- When it freezes, it expands by about nine percent and loosens the plaster.
- After thawing, a larger cavity remains.
Each round of damage exacerbates the problem: a hairline crack becomes a continuous crack, a hollow spot a spalled area. If moisture remains in the masonry, it often leads to infestation by algae, mold, and other fungi. Then, only a facade renovation, usually including retrofitted insulation, will help. Read our article to find out what the warning signs are. 5 signs that your facade needs renovation.
Anyone wanting to winterize their facade shouldn't rely on the weather forecast. While it states the air temperature, the crucial factor is the temperature of the wall itself. Under clear skies, a facade radiates heat at night and will be below the indicated temperature in the morning. Five degrees Celsius in the afternoon, therefore, does not mean five degrees Celsius on the wall at four o'clock in the morning. This is also pointed out by... Swiss Painters and Plasterers Association in his information sheet.
What damage should you look for in autumn?
Most winter damage gives warning signs, but appears harmless in autumn. The overview ranks the typical findings according to urgency:
| Damage pattern | Probable cause | urgency |
|---|---|---|
| Hairline cracks less than 0,2 mm | Shrinkage of the plaster layer | low, observe |
| Continuous cracks from 0,3 mm | Movement in the subsurface | hoch |
| Green or black coating | persistent humidity, little sun | Means, clarify the cause |
| Dull sound when tapped | Loss of adhesion of the plaster layer | hoch |
| Damp base, white efflorescence | Splashing water, rising damp | medium to high |
How can you recognize cracks and hollow spots?
For cracks The width, not the length, is the determining factor. Fine, network-like cracks are caused by shrinkage of the plaster and often remain unnoticed for years. However, from about 0,3 millimeters in width, a crack will allow water to penetrate the structure during driving rain. Cracks that follow a clear line, such as along construction joints or across window corners, are particularly critical.
Hollow spots are harder to find because the surface appears completely intact there. Tap the accessible areas with your knuckle or a wooden stick, especially around windows, at building corners, and under sills. If it sounds high-pitched, the plaster is firmly attached. If it sounds dull, the layer has come loose. Such areas will freeze through and, in the worst case, fall off completely.
How does the specialist company proceed to make your facade winter-proof?
A facade inspection is more than just a glance from the street. It follows a specific sequence because individual findings only become clear when considered in context. These six steps are part of it:
- Assess each page individually. Weather-facing sides, bases, and shaded areas suffer different types of damage, therefore each facade side is recorded separately.
- Check the substrate. Tapping reveals hollow areas, the wetting test shows the absorbency, and an adhesion test shows whether the old paint is still holding.
- Measure humidity. Only the measured value distinguishes a damp surface from a soaked component.
- Classify cracks. The crucial factor is whether a crack is only in the coating or extends into the substrate.
- Check connections and drainage. Window sills, sheet metal work and downpipes are the most common entry points for water.
- Document and evaluate findings. Finally, there is a list with photos that separates what needs to be done before winter and what can wait until spring.
The assessment is based precisely on this process. MVM AG Their facades. Schedule a facade check now, as long as repairs are still possible.
What kind of work is still possible in the fall?
Minor repairs can still be easily carried out now: closing cracks, sealing connections, and removing loose material are all part of the job. A new coat of paint, however, can wait until the next construction season. Depending on the location and weather, this window of opportunity often extends well into autumn.
The wall temperature, not the calendar, determines when this window of opportunity closes. Plaster, repair mortar, and the coating of the repaired area require a minimum air and substrate temperature of five degrees Celsius during application and throughout the entire drying process. Humidity is also a factor: the wall should be at least three degrees warmer than the dew point, the temperature at which moisture condenses into water. Otherwise, it will condense directly on the fresh coating.
"Autumn is the best time of year for repairs. The ground is dry after summer, the temperatures are still sufficient, and the repair will last through the winter. Anyone who waits until spring will have to repair the same area over several square meters."
Conclusion: Checking now is cheaper than repairing in the spring.
Winter doesn't uncover new damage. It exacerbates the damage already present in autumn. A crack as small as 0,3 millimeters, a hollow spot behind an intact surface, a base with dark edges: these are precisely the places where water penetrates and builds up pressure when it freezes. Those who discover these spots now can repair them with manageable effort. Those who find them in March will need scaffolding.
Making a facade winter-proof therefore primarily means observing, documenting, and assessing the situation while repairs are still possible. There's time for design work until spring. But not for anything that keeps water out.
Contact Sie uns jetzt and go into winter with a clear inventory.
Frequently asked questions about making facades winter-proof
Up to what temperature can you paint the facade?
The temperature must be maintained at around five degrees Celsius for both air and substrate, and at eight degrees Celsius for certain silicate products. This temperature must also be maintained during drying, including overnight.
When are cracks in the facade dangerous?
Cracks wider than approximately 0,3 millimeters are particularly problematic, as they allow water to penetrate the structure during heavy rain. Cracks that follow a clear line, such as those across window corners, are also critical.
What to do if the exterior plaster is coming loose?
Remove the loose layer and rebuild the surface once the subsoil is dry. Until then, the area is considered open, and water will penetrate it with every rainfall.
How can I tell that my facade needs to be renovated?
Chalking or faded surfaces, recurring growth of vegetation, cracks across multiple areas, and damp patches in the base are all signs of wear and tear. Individual damages can be repaired, but as soon as several signs appear together, a complete renovation is worthwhile.