When raining it would appear that water is seeping in between brickwork and blockwork, runningdown inside and coming out above the double glazed window outside. I have had two holes drilled outside to prove this fact and rain water comes out of these holes. The rainwater does not show itself until about 24 hours after raining. Running down the kitchen window. Is there supposed to be a cavity closer to stop water entering between the brick and blockwork. I have looked inside the loft and there is no sign of any leaking. Dry as a bone. ???? :cry:
you need a cavity tray fitted above the window,but before installing it,hire a borescope (fibre optic camera)from the local hire shop and see where the water is coming in from.Hose the wall down it may just be a simple case of a bit of sealant.
Since the water exists outside the wall there is a fair chance you already have a cavity tray. Try sealing the outside of the wall with silicone waterproofer as suggested by WB and see if this cures the problem.