Is my newly fitted window the cause of water ingress?

grantcar2

I had a new uPVC window fitted a few weeks ago. There was some rainy weather and a few days later a large damp patch developed on the internal wall directly under the window [in around the middle]. Looking outside the window, I could see the mastic putty was missing along the bottom of the window frame, but I could still see the hint of something white directly under the window frame [ie the sealant], but is was also all wet under there where the rain had been dripping. The is also a crack on the external window sill, but appears to have been like that for many years. The window guy came back out and scratched his head a bit, then he said there was a hole in the corner of where the window was fitted and shouldn't be like that [he owns the company, his joiners did the work]. He suggested that the water was getting in and travelling along the dpc [damp proof course], pooling and then leaking against the internal bricks and hence through to the internal plaster. His joiner came out and put a bit of mastic putty under the window and that was that. I questioned the cause of the leak and then company denied that the leak was anything to do with the windows and said the damp must be caused by something else! There are no obvious cracks in the external render or anything else that I can see. Any advice?

ElephantBoy57

It does look like there is a gap, there looks to be a make on the bottom concrete sill that is where the old window was.

You would have thought the window man that came out would have spotted that, I am no expert, just looking at a photo.

grantcar2

Do you think the crack in the window sill could be letting in the water?