Hi Houzzers,

Just wondering if anyone can help with a question about plastering?

We had our 2-storey house built 4 years ago. We have a 5-metre-high internal gyprock wall in the stairwell ( 2 plaster sheets joined horizontally, I assume with control joints in between). In recent years, the lower plaster sheet has "bowed" out to about 5 mm (1.2 metres wide) from the top sheet and both sheets are no longer flush (see pics.) During construction, should the join have been taped or filled before painting? Looks quite ugly. What has caused the bow and how is the best way to fix it? Should we get the builder back?

Thanks! :)