What is it?
A method of tracking whether a crack is ‘active’ (moving) or ‘passive’ (stable).
What does it look like?
[Insert Photos] Examples of pencil marks, glass tell-tales, and digital crack gauges.
Common causes
1. Seasonal changes
2. Ongoing subsidence
3. Vibrations
4. Initial drying out
How serious is it?
Rating: Medium Concern. Monitoring is a vital step in diagnosing the severity of structural movement.
How to tell which cause you have
If the crack opens and closes with the seasons, it’s likely thermal. If it only gets wider, it’s likely structural.
What should you do next?
Mark the ends of the crack with a pencil and date it. Check again in 3 months.
Typical repair options
No repair should be done until monitoring confirms the movement has stopped.
Typical repair costs (UK)
£0 (DIY pencil marks) to £500 (Professional monitoring).
Frequently Asked Questions
1. How long should I monitor for? At least 6-12 months.
2. What is a tell-tale? A mechanical gauge fixed over a crack.
3. Can I use tape? No, tape stretches and is unreliable.
4. Should I monitor inside or outside? Both.
5. What if it moves 1mm? Record it and continue monitoring.