Need help desingning an OUTDOOR enclosure

[b23ball23]

OK, heres the deal:

my mom in no way wants a blacksnake inside the house...even though i already have a milk snake!!!...she has heard stories of how my dad had one and it got out...yada yada

well i have a deck and underneath it there is plenty of room where i could build a cage to enclose a black rat snake

well i was wondering how big....and what material I should use....to make it escape-freee and healthy for a potentially a 7 foot snake

Do i need heating....how??(since its outdoors)..


The deck will prevent some rain.....but it still drips through the cracks...how do i make the cage so it does not get soked and ruin the substrate

ANY help is awesome....this will be a good project!!!!

BEN