

We renovated our 1919 semi-detached double brick house about 4 years ago. Since then the section of the original shared wall (just next to where the renovated wall begins) has had some diagonal cracks appearing. I patched them a couple of years ago with just poly filla and that held up fine for a year or two. However recently the cracks have reappeared quite quickly and towards the ceiling the wall is now bulging out which seems to have happened over the last week. We contacted our builder and he noted that I might need base coat to bind it. Is that gyprock? And is that ok to try myself? Or should we get a professional in?! Cheers