Since I find it hard to get decent glue over here, I tend to use Double sided tape for my builds. Its less messy, gives an instant bond so that you need not wait for glue drying before continuing etc etc.
However, before you make a decision to rebuild the lower level, be advised that double sided tape has a shorter lifespan than normal glue..... dependant on heat and humidity in your location (yeah I'm pretty much screwed where I am LOL). Some of my Mayhem buildings and Caveworks stuff has already started to come apart.
Just a warning before you move ahead. Be sure to post pics when its finished
