Reno@Clementi III - where new walls and old walls meet

Where new walls and old walls meet often will produces hairline cracks. This is something which is unavoidable and happens all the time. So when does it happen? and why?

when the walls expand on hot days and contracts when the air conditioning is turned on, the new and old walls start to push and contract against each other and thereby forming the thin crack line. This occurrence can start anyway between 3 months to even years.

The fastest way is to paint over it but the hairline cracks might occur again. Other methods is to putty over the crackline, let it dry and paint over.

But if you ask me, I probably will just look at it as an added character to the place. It's somewhat like having cement floors that comes with its natural hairline cracks which is its natural beauty to begin with.