Can I spray the ceiling with the FLEXiO sprayers?

Yes, you can, but never tip the sprayer upwards at more than a 45-degree angle while using the FLEXiO handheld models.  If the sprayer is tipped upwards at more than a 45-degree angle material could get into the turbine and damage it.

For ceilings, the stationary FLEXiO models (4000, 4300 or 5000) are the better option because the gun is separate from the turbine and can be tilted upwards, up to 60 degrees.

Watch this helpful video on painting a ceiling, https://youtu.be/cVTWAlI2O7g.