I read that most straight hairline cracks are pretty normal, especially around windows or doors, due to settling and stress. Mine happens below a pretty wide extruding window and is not perfectly straight. It has a short horizontal region before turning vertical. The width of the crack is less than 1mm (1/25 inch).
Is this something of concern?
Is there any downside to leaving the crack as is behind baseboard heater?
My rough plan is to repair it with tape and drywall mud for the visible portion.
Best Answer
These type of cracks are common and certainly not major. IMO the size of the crack doesn't warrant taping. I would just spackle over it with a putty knife. Smooth it flat and let it dry. Work the spackle into the crack as much as you can. This will help prevent further cracking. After drying just use a damp sponge or cloth to wipe the excess off the surface along the crack. Touch up with paint if needed.
"Is there any downside to leaving the crack as is behind baseboard heater?"
There is no evidence that there are any structural issues from what you describe and show in the pic. I wouldn't be concerned about the crack behind the baseboard. This appears to be strictly a cosmetic issue.