Hi all, I had a large crack in the wall which I think was caused by damp around the window. Anyway I filled it and and painted over and it looked great. Week or so later and I've noticed hairline cracks form on the join of the filler / crack. Slapped a bit more filler over the top and gave it a light sand and left it. Few days and and I now notice hairline crack forming again.
What's the deal here? Do I need to sand it back, tape the crack which I didn't do before. Fill and sand again? Or do I just need to use a different filler? This is the one I have been using in the link below. On thing also is this room is south facing and the sun hits right where the filler is. So I don't know if maybe the sun drying it out is doing it?
https://www.screwfix.com/p/no-nonsense-interior-ready-mixed-filler-white-off-white-1kg/555gt
What's the deal here? Do I need to sand it back, tape the crack which I didn't do before. Fill and sand again? Or do I just need to use a different filler? This is the one I have been using in the link below. On thing also is this room is south facing and the sun hits right where the filler is. So I don't know if maybe the sun drying it out is doing it?
https://www.screwfix.com/p/no-nonsense-interior-ready-mixed-filler-white-off-white-1kg/555gt