penetrating damp bay window

[benjawon]

There is damp coming through the bay window wall at the top, below the window at the two corners only when it rains. Outside the windowsill - which is made of mortar - is cracked at the corners also and has not been painted for some time. The brickwork outside has been rendered but looks pretty sound.

I think that the windowsill could be the problem. Without having to re-render the whole window sill, is there a product I could use to patch up the cracks and is there something I can use to make the windowsill waterproof?

its all dry at the moment because its not rained for some time.

 

[noseall]

Patching any external weather bearing surfaces will only be a temporary solution.

Sooner or later the cracks will reappear unless you do something more permanent/robust.

I'm finding it difficult to imagine a sill made from mortar?