DIY Vivarium help!!

jacoblee91

New member
So I'm building my first Vivarium. And I hosted to great stuff spray foam background and I carved it out and put the silicon on and the dirt. And now 2 days later to let it all dry and stuff and the foam is shrinking. Started coming off on the top and now coming in on the sides. What am I doing wrong and would siliconing the edges be safe enough to put my geckos in the viv?
 
Top