Rendering Walls – The Most Common Issues Clients Face
Why is it important to know the risks before commissioning wall rendering?
Wall rendering (applying external plaster) is a great way to protect your facade from weather conditions and improve the appearance of your building. However, like with any construction service, if something is done incorrectly, problems may arise. In this post, we discuss the most common issues our clients report – and how to avoid them.
Cracking plaster after a few months
This is one of the most frequent problems. Cracks can have many causes:
- Too rapid drying of the plaster (e.g., working under direct sunlight),
- Lack of reinforcing mesh (fiberglass mesh),
- Poor surface preparation (dirt, dust, loose parts),
- Too thin or uneven plaster layer.
The solution? Proper material selection, working under suitable weather conditions, and experienced contractors who know how to handle every stage of application.
Plaster peeling or flaking off
Plaster that starts to detach from the wall is not only an aesthetic issue but also threatens the durability of the entire facade. The most common causes are:
- Moisture in the walls (e.g., lack of waterproofing),
- Poorly chosen primer or no priming at all,
- Low-quality plaster.
That’s why it is important to assess the technical condition of the walls before starting the rendering. For older buildings, lime or silicate plaster is recommended because it “breathes” and does not trap moisture inside.
Discoloration on the plaster surface
Sometimes just weeks after application, stains, streaks, or color differences appear on fresh plaster. This often results from:
- Uneven mixing of the plaster,
- Incorrect water ratio during mixing,
- Rainfall soon after application,
- Lack of impregnation or use of low-quality finishing paint.
Remember that textured and thin-layer plasters should be finished on the entire facade in one day – leaving one wall for later will cause visible differences.
Algae, mold, and greenish stains on walls
On some facades, especially those facing north or shaded, a greenish tint appears over time. This usually happens because:
- The plaster is not breathable enough – moisture stays trapped inside,
- Lack of waterproof or biocidal treatment.
We recommend using modern silicone or silicate plasters with additives resistant to microbial growth.
Unsatisfactory visual effect
Sometimes clients expect a perfectly smooth surface or a specific color, but the final result differs from their expectations. The main reasons include:
- No prior color samples,
- Wrong texture choice (e.g., too thick a finish),
- Poor lighting conditions during evaluation (daylight vs. artificial light).
Therefore, we always suggest making a small test patch before starting large projects.
How to avoid rendering problems?
Three key points:
- Proper wall preparation and suitable weather conditions,
- Use of high-quality, proven materials,
- Working with experienced professionals who have good references.
Well-done rendering can last for many years without major repairs. It’s worth investing in quality from the start – it pays off with peace of mind and durability.