You are quite right John. I'm sorry. You never said you were convinced their proposed solution would work.
It was my assumption given how you were keen to go along with their proposal on this issue.
I have made some enquiries, but doubt that I will be able to find a Thai engineer to take on the job of evaluating other possible solutions.
So as you say, we have no option but to accept Pornpol's assurances and get the job done, sooner rather than later. The heavy rain over the last few days has increased the number and severity of roof leaks, and I am very keen to get the footing repaired so that Alex can get on with fixing the leaks.