Xpvc rack assembled with some trials

I just finished assembling my Xpvc rack after some beginner issues. It holds four 6qt tubs on the top shelf with some room in between, three 12.7qt on the shelf below, and two 41qt on the lower two shelves. I've left some room for another shelf since I have one spare board cut to size.
Heating will be heat tape ( which I need to pick up from the show) and will be controlled by a herpstat.
I went to a local sign shop and got two 8 foot by 4 foot Xpvc boards ( 1/2 inch gator board) for $110 a board with free cuts. This left me with four 36 x 18 inch boards left over, one for expansion and three for a boa display cage.
Something to keep in mind if your building your own. I initially used inch long screws to secure the levels. I assembled it upside down and when I flipped it upright the whole thing leaned apart and the screws ripped out of the foam. I disassembled it and used 2 1/2 inch long screws and installed brackets underneath each shelf for support. The brackets may not have been needed but a longer screw size is a must. There was some exposed screws from the brackets but not anywhere that would be in contact with animals. I plan on filing the ends or covering them with some rubber nubby bits.
I can post photos of all the supplies if there is interest. I mostly wanted to get this out so no one made my mistake of screw size.
I know it's not perfect or professional by any means but I am quite proud of myself. It is my first construction DIY project and was certainly a headache at times.

http://tapatalk.imageshack.com/v2/15...5bd07f3a2b.jpg


0.1 Butter 0.1 Pastel
1.0 Mojave 1.0 Queen Bee

Man i dont think that is going to hold up. It looks like it is sagging in the middle already. Now throw some heat on them and a tub with a heavy snake and water dish. Ive tried a three wide rack myself a long time ago and even with a back on it for added support it still started to sag quick. Id cut it in half and make two single stack racks.

Looks fine to me. You will get sagging but that's easily prevented with a brace or two in the back. So long as you screw each shelf into the brace, and run it all the way to the floor, it'll be able to do it's job and prevent sagging.

There is no sagging in person although it does bow slightly with 3000g of weight centered in the middle of a shelf. The reasoning for the width is so I can have 41q tubs sideways instead of long ways.
I do believe the bowing is cause for a brace. I have some scrap pieces that should work just wonderfully. Do you think it calls for two braces on the back or one centered on the back?
My largest BP is 1600g so I figure a 3000g test is sufficient. I'll take any help I can receive. I know I'm a beginner but I could not find any premade racks that could house hatchlings to adult males.
It will be some time before anything live goes in it so by all means critique it away.

http://tapatalk.imageshack.com/v2/15...a1bf010c9e.jpg


0.1 Butter 0.1 Pastel
1.0 Mojave 1.0 Queen Bee

It depends on the wiring you plan.

I would probably use one brace in the center but if that will complicate the electrics then two braces near the middle of the back should let you cable easier. :)

I added a center brace throughout the shelves along the back. It doesn't quite reach the very top but it does meet the bottom of the topmost shelf (the baby level).
I had tested beforehand with an adult tub and approx. 2000g of weights. There was minimal bowing. With the brace a shelf holds the 3000g book stack in the center with a very slight bow towards the front. With the weight spaced evenly I can't see anything.
I intend on running one strip of 3 inch flex watt across the top two shelves and two strips on the adult shelves at one end. I can't foresee any wiring issues with the brace centered but I'm sure I can work around it.
I am still undecided if I should go for the four inch flex watt and if I can use a herpstat 4 or if I will need two 2s.

It's a complicated design to engineer for sure. I would try a cheap piece of melamine across the entire back for support. I used zinc coated 1 5/8" drywall screws and pre-drilled all holes.

1/2 a sheet would have got you a 5 high 28qt rack. I get 11 high out of one sheet. Here is two V-18 racks stacked, a 10 high 28qt rack and an 11 high 28qt rack.

http://i254.photobucket.com/albums/h...psf0386555.jpg

11 high 41qt rack (two full sheets):

http://i254.photobucket.com/albums/h...pscbbd8daf.jpg

I would use all 4" heat tape and just get a HerpStat 1. More than enough to handle to load.