If you mean spray loose fill insulation, you need to build up the sub floor with 2x's over the ceiling joist so as to not press the insulation down, and then install the flooring (1/2" plywood). If yo mean spray foam insulation, it depends on where it is sprayed. Normally, when we do spray foam it is sprayed on the bottom of the roof between the trusses, so it would not be in the way .
Courtier...has the right approach. Most ceiling joists have insulation that rises above. so some form of additional "framing" will be required to get above it.
If you mean spray loose fill insulation, you need to build up the sub floor with 2x's over the ceiling joist so as to not press the insulation down, and then install the flooring (1/2" plywood). If yo mean spray foam insulation, it depends on where it is sprayed. Normally, when we do spray foam it is sprayed on the bottom of the roof between the trusses, so it would not be in the way .