Abstract: A toilet installing assembly includes a bladder that has an upper panel and a lower panel sealed together along peripheral edges of the upper and lower panels. The bladder is selectively inflatable and is substantially planar when not inflated and has a generally rounded shape when the bladder is inflated. An inlet valve is fluidly coupled to the bladder. The bladder is positioned around a toilet drain and then inflated. A toilet is positioned on the bladder. The toilet is aligned with the toilet drain and with a plurality of mounting studs. The bladder is then deflated and the toilet lowered onto the studs.