I would post pics but sadly about 3 months ago, my digital camera broke and me being Mrs. take everything apart and try to fix it ... made it worse lol. I ended up chucking it after I broke the shutter button, trying to open it up.
I may go and try to pick up another digital cam if I can find one cheap. We will see, but if I do, I will post pics of how far we have gotten. I think after tonight's 2 coats dry we should be ready for the sealer and then weeeeeeee, yeahhh, we can put in his Pro heat panel and the A419 we have, and Sosa will have one nice set up.
I have a few concerns about what you will be using. The Styrofoam packing blocks you have will be wayyyy to large and stand out too far from the wall, taking up a major portion of your viv. we used 1/4 & 1/2 inch and it actually takes up more room than you think once you get on about 5 coats of the Tile Adhesive over it.
Just keep in mind with the tile adhesive a 1/2 foam wall will protrude into the viv 2 inches or more depending on how many coats you end up needing to apply.
As far as the mortar goes, the reason you use tile adhesive is because it is super fine, it is like clay to an extent. Anything with even a remotely sandy finish will rub on your snakes skin and really rip it up, casing them serious injury or even death.
We have used mortar before for a few crack repairs and no matter how much you water it down it still has a grainy feel, so please don't use that, I beg you.
On your Styrofoam blocks just cut them in two or three, thickness wise. We used two different sizes to make it dimensional. When you get to adding the Styrofoam to make shelves it will seem really shaky and not real secure, just hot glue it in place and use the expanding foam on the under side, it is just for holding it in place until you get a few coats of the adhesive on. After several coats, those shelves are rock solid.
We just kind of threw shelves here and there, short pieces leading to a larger shelf, etc. and one on the side that is tilted for him to get closer to his heat panel if he wants to.
M.E.K. is methyl ethyl ketone - The site said paint thinner would work but I tried three different types as well as pure acetone and none of them worked, so I went onto a few science sites and researched solvents and found that M.E.K. is used to melt Styrofoam and it works great.
It doesn't like super melt so you can do it a few times and get the groves and gouges you want in your foam to make it look the way you want. Just don't use plastic brushes because it will melt them. I used .89 short bristle wood brushes from local hardware store.
The M.E.K. is sold in the solvents aisle at hardware stores right next to the paint thinners and lacquer. Here is a pic of it in case you have not seen it before.
They sell it in small containers, but this was the only pic I could find to show you what it was.
Anyway hope this helps.
unch: Umm, ya know my post about making the fake rock wall? 
