The roof is corrugated tin (quite thin) with sprayed material on the inside to add some sort of mass/diffusion. The walls are what appears to be double brick. As ive mentioned it is just not possible to do an analysis of the roof itself from above the roof as this would be quite unsafe...
Its actually a loud band and PA system so SPLs can get quite high on the inside. The building is quite large (sort of a hall) with very high roof (5+ metres) making the measurments u spoke of very difficult and unsafe.
I managed to find the incoherent plane radiator you mentioned in a Hansen...
I have taken equivalent SPL measurements at various distances outside of a building which is housing a noise source. I am trying to prove that sound is leaking from the roof and reaching ground level by diffraction.
If only a single wall was propagating sound how would it decay? Obviously a...