Setting up 4'x2'x2' terrarium - snake den material and size?

[mef1975]

I'm wondering if these materials would be okay for making a custom bonsai plant pot, as well as, a snake den... Also, how big a den is required for corn snakes?

http://www.homedepot.com/p/UGL-1-ga...gclid=CLaF6ai-uMUCFdORHwodPn8AjA&gclsrc=aw.ds

http://www.homedepot.com/p/Quikrete-50-lb-Fast-Setting-Concrete-Mix-100450/100318521

Or, can you suggest something that's just as lasting, yet not less toxic?

 

[mef1975]

Or, can you suggest something that's just as lasting, yet not less toxic?

I meant not as toxic.