Buildings often look strong and permanent. However, many homeowners notice small cracks appearing and disappearing at different times of the year. These are known as Seasonal cracks. Although they may look worrying, most Seasonal cracks are common and manageable if understood correctly.
This blog explains Seasonal cracks in simple English, covering causes, types, real examples, standards, repairs, and how Seasonal cracks differ from one place to another.
What Are Seasonal Cracks?
Seasonal cracks are cracks that appear in buildings due to seasonal changes such as temperature variation, humidity, rainfall, and soil movement. These cracks usually widen in one season and reduce or close in another.
In most cases, Seasonal cracks are not structural failures. Instead, they are the natural response of building materials to expansion, contraction, and moisture changes.
Why Do Seasonal Cracks Occur?
Seasonal cracks mainly occur due to environmental changes. The most common reasons include:
1. Temperature Changes
Building materials like concrete, brick, and plaster expand in heat and shrink in cold weather. This repeated movement causes Seasonal cracks over time.
2. Moisture Variation
During the rainy season, soil absorbs water and expands. In dry seasons, it shrinks. This movement affects foundations and leads to Seasonal cracks in walls and floors.
3. Drying and Shrinkage
Plaster and concrete continue to dry slowly after construction. Seasonal weather speeds up or slows down this process, resulting in Seasonal cracks.
4. Poor Construction Practices
Lack of expansion joints, improper curing, or low-quality materials can increase Seasonal cracks.
Common Types of Seasonal Cracks
Seasonal cracks can appear in different forms, depending on location and material.
Hairline Cracks
Very thin cracks on plastered walls or ceilings. These are the most common Seasonal cracks and are usually harmless.
Vertical Cracks
Often seen near columns, doors, or windows. These Seasonal cracks are caused by temperature-related expansion and contraction.
Horizontal Cracks
Appear due to moisture changes or minor settlement and may widen slightly during extreme seasons.
Floor Cracks
Common in ground-floor slabs, especially in areas with clayey soil that expands and contracts seasonally.
Seasonal Cracks vs Structural Cracks
It is important to understand the difference.
| Seasonal Cracks | Structural Cracks |
|---|---|
| Appear and reduce with seasons | Continuously widen |
| Usually thin and shallow | Deep and wide |
| Mostly non-structural | Affect building safety |
| Easy to repair | Require structural repair |
If cracks keep growing every year, they should be inspected by a professional.
Case Study: Seasonal Cracks in a Residential Building
A two-storey house in Pune developed visible wall cracks every summer. The cracks reduced during the monsoon season. After inspection, it was found that the soil below the foundation was clayey and highly sensitive to moisture changes.
Solution applied:
- Flexible crack fillers were used
- External waterproof coating was applied
- Drainage around the building was improved
After these measures, Seasonal cracks reduced significantly within one year.
How Seasonal Cracks Differ from One Place to Another
Seasonal cracks vary based on location, climate, and soil type.
Hot and Dry Regions
Areas with high temperatures experience more shrinkage cracks due to heat expansion and moisture loss.
Cold Regions
Freeze–thaw cycles cause materials to expand and contract frequently, leading to Seasonal cracks.
Coastal Areas
High humidity and salt content affect plaster and reinforcement, increasing Seasonal cracks.
Clay Soil Areas
Clay expands in monsoon and shrinks in summer, causing foundation movement and Seasonal cracks.
Thus, the same building design may perform differently in different regions.
Relevant Codes and Standards
In India and the UK, building standards guide crack control:
- IS 456:2000 – Concrete design and crack control
- IS 3370 – Water-retaining structures
- BS EN 1992 (Eurocode 2) – Control of cracking in concrete structures
These standards recommend expansion joints, proper curing, and material selection to reduce Seasonal cracks.
How to Repair Seasonal Cracks
Repair depends on crack size and location.
Minor Cracks
- Clean the crack
- Apply acrylic or polymer-based crack filler
- Repaint after drying
Moderate Cracks
- Use flexible sealants
- Apply fibre mesh before replastering
Prevention Measures
- Provide expansion joints
- Ensure proper curing
- Maintain drainage around foundations
- Use good-quality construction materials
Preventive care is the best way to control Seasonal cracks.
Example of Seasonal Crack Behaviour
A plaster crack measuring 1 mm in summer may reduce to 0.3 mm during winter or rainy season. This clearly shows how Seasonal cracks respond to environmental changes rather than structural failure.
FAQs on Seasonal Cracks
Are Seasonal cracks dangerous?
Most Seasonal cracks are harmless if they are thin and stable.
Do Seasonal cracks need immediate repair?
Hairline Seasonal cracks can be repaired during routine maintenance.
Can Seasonal cracks be fully avoided?
They cannot be completely avoided, but proper design and construction can minimise them.
Do Seasonal cracks come back after repair?
Yes, if flexible materials are not used, Seasonal cracks may reappear.
When should I consult a structural engineer?
If cracks widen continuously or exceed 5 mm, professional advice is necessary.
Conclusion
Seasonal cracks are a natural part of a building’s life cycle. They occur due to temperature changes, moisture variation, and soil behaviour. Although they may look alarming, most Seasonal cracks are non-structural and manageable.