Thanks Eric. Do you know whether the SWP E-R Efflorescence Rid product is likely to also strip paint off the wall?

Thank you very much for that Eric!Yes, there is elevated dirt on two of the walls which is likely leading to the accumulation of water. I'll see if I ...

Thanks Mitchell.I spoke to the builder and he said that it looks it's simply a knot in the wood, and that it can be filled / sanded and then painted o ...

Thanks for getting back to me.No - it doesn't seem to do that, so hopefully it's not termites!