Thanks Dave. Just going through and it sounds like it would require a proper investigation, drilling etc works. Don’t think the seller will agree to this.
I asked the agent to check with the seller and they tell me all windows and patio door were replaced in approx. 2003 by previous owner. They are unsure if patio door was initially a single door and then changed to these double, sliding doors. Seller also says she hasn’t noticed any cracks however, hasn’t lived there for around 5 years. Sounds like this was a rental property.
moisture meter in the corner shows 15% (low as per the table at the back of the meter)