Mesh will not help this problem as it does nothing the crack will travel through the mesh to the surface.
Radiant ceiling heat cracks.
Radiant ceiling heat is a style of heating that is significantly different from the radiators or forced air ducts that you may be used to.
For rooms with a height of over 3 5 meters a higher flow temperature is required.
1 ceiling and walls are hung and finished electricians install ceiling cables after cables are installed 2 coats of a plaster product called radex is applied over the cables then a texture is applied.
Where ceiling heating makes sense.
Btw i had something similar many years ago 2x4 radiant panels that dropped into my rec room s drop ceiling grid.
I owned a condo a few years ago with radiant ceiling heat similar construction timeframe i guess warm air fell in the 70s.
In fact the temperature variant from ceiling to floor is only about 1 c 2 f.
In the older form electric heating elements are sandwiched between a layer of drywall and a layer of plaster.
Ceiling radiant heat is an interesting historical anomaly.
Low temperature ceiling heating can be used in rooms with a height of between 2 5 and 3 5 meters.
Here the radiant heat can unfold in the best possible way with flow temperatures of between 26 and 40 c.
A direct transference of clean even heat from object to object without fans pumps or hoses silent motionless and invisible.
But unless you re really intent on period authenticity bus s suggestion is probably the right one install something more maintainable and more efficient.
Radiant ceiling heat comes in two main forms.
The thing about this radiant heat cieling is the cracks are occuring from heating and cooling of the cieling in a rapid manner not from structual movement that is why the crack will stay behind the paper tape.