Water is coming through the grout joints in the bathroom leading to blown plaster and loose tiles 2/3 up the wall, same height as window seal.
House is in Rickmansworth, 1930's detatched, solid wall, rendered, weathershielded 2 years ago, with new aluminium windows
Chimney stack was removed 2 years ago and damp was present before this date, roof has been checked, patched 3 times, felted and loft inspected - still no fix - roofer has suggested new roof!
Building surveyor has stated not a roof problem but cannot identify solution. Has suggested sealing air brick and filling cracks on external wall.
Who would I ask to fill cracks on external wall - general builder ? and of course what specification of work should I request ?