Wet patches under window in extension build

ravendude

Hi,
Building an extension at the moment.Its at first fix stage.

Afte tthe wild weather at the weekend I noticed 3 wet patches under a large window, in a line. See here:
https://drive.google.com/file/d/1WLXNE5qurxC1yJFarzRL5PRiBGpbugE0/view?usp=sharing

The line is roughly at the level where the cill would sit, the outside cill is approx 150mm thick.. There is red brick to the outside and its siliconed on the outside to the top and sides but not the bottom. There is def DPC, I can see it under the cill to the outside.

Wind and rain was pretty side-ways over the weekend, but would not expect such wet patches...

Will get the builder to check obviously but I don't have 100% trust in him to be honest.
What would cause this? Might it just need some silcone to the bottom of the frame?

Thanks!

I

Who2

ravendude wrote: »

Hi,
Building an extension at the moment.Its at first fix stage.

Afte tthe wild weather at the weekend I noticed 3 wet patches under a large window, in a line. See here:
https://drive.google.com/file/d/1WLXNE5qurxC1yJFarzRL5PRiBGpbugE0/view?usp=sharing

The line is roughly at the level where the cill would sit, the outside cill is approx 150mm thick.. There is red brick to the outside and its siliconed on the outside to the top and sides but not the bottom. There is def DPC, I can see it under the cill to the outside.

Wind and rain was pretty side-ways over the weekend, but would not expect such wet patches...

Will get the builder to check obviously but I don't have 100% trust in him to be honest.
What would cause this? Might it just need some silcone to the bottom of the frame?

Thanks!

I

More than likely the dpc wasn’t wrapped properly up around the cill, it was then just filled up against with concrete and soaking straight through to the inside.

ravendude

Who2 wrote: »

More than likely the dpc wasn’t wrapped properly up around the cill, it was then just filled up against with concrete and soaking straight through to the inside.

Hmm., looking at some diagram there, this seems to make sense.
Presume the only remediation is to pull out the windows, sort and refit?
I suspect the builder will be proposing "a bit of silicone" or something like that

Who2

If it was my own I’d be breaking back the inside leaf under the bottom of window first to see if that is the problem( just down to the first block or the line that the damp is) and go from there.