Cracks in plaster after extension

[flobelle]

two years ago had a kitchen extension to the corner of the house, which meant two RSJ's installed holding up the corner of the house.
Noticed after 3 months small hair line cracks in the bathroom, which is the upper part of the house on the corner to the extension. Now more cracks appearing and tiles have moved and bulged in the bathroom, again above the extension.
Is this normal?

 

[^woody^]

The situation you describe can be quite normal and common.

The question should be ..... "Is this related to the building work, and is it a once only settlement or ongoing movement?"

The answers would require images of the wall for a list of possible causes and lengthly debate, or a site investigation by a suitable person for an actual diagnosis