Recommendations to prevent cracks appearing near window board

[icon_boy]

Hello.


Can anyone recommend a way to prevent cracks from re-appearing when filtering in, on the window board near the edges (as it meet with the internal wall). I have used Ronseal white wood filler, which states that’s it flexible, however Im seeing cracks appear after a few weeks. I would like to find a solution before I paint the windows boards.


TIA

 

[jacko555]

On mine, I ran a bead of caulk, smoothed with a wet finger.
It's flexible and paintable. Making a transition of solid filler will crack due to expansion/different thermal properties of wood/plastwe. I'd run a screwdriver or blade or something so there's a small 2mm gap separating the wood filler and plaster first.
Don't skimp on the caulk. The £1 stuff is rubbish.

 

[icon_boy]

Thank you, that makes sense!