Reptile & Amphibian Forums

I've recently given some thought to constructing my own cages, as opposed to buying them, because shipping costs are often rather prohibitive.
To give an outline of my thoughts, I'd like to make the cage dimensions somewhere along the lines of 60" x 24" x 36" or, preferably, 72" x 24" x 36" (length by width by height), and I was considering using 3/4" plywood as the primary material. I'd also like to line the interior of the cage with FRP to make it waterproof and easier to clean. I'd be keeping tropical snakes (Spilotes, Pseustes, etc.) in the enclosure so it needs to stand up to elevated humidity and direct spraying, while also possessing qualities that will make cleaning simple. I like the idea of sliding glass doors, as I think they would be easier to install than swing doors - I'm not much of a carpenter, to say the least. I'll probably heat the enclosures with radiant heat panels. The cages must be stackable.

On to the questions:
1.) Is there a particular plywood that would stand out as more efficient for this type of enclosure? Particularly one that wouldn't sag at lengths of six feet.
2.) Would it be a good idea to line the cage with FRP? If so, how would I go about laminating the FRP to the plywood? Is there a better alternative for waterproofing?
3.) I plan on mounting the heat panels directly to the FRP interior; is it possible that the heat could cause the FRP to separate from the plywood? If so, what could I do to avoid this?

I'm sure I forgot to ask some questions here, but if anyone has something to offer that may be applicable in this circumstance, I would be very appreciative if he/she would share. Or, what might work better for a cage of this size?
-----
Roy Blodgett
Green Man Herpetoculture
royreptile@yahoo.com

1.1 Spilotes pullatus
2.2 Pseustes sulphureus
1.1 Pseustes poecilonotus poecilonotus
1.1 Lystrophis pulcher
1.1 Boiga dendrophila dendrophila
1.2 Crotaphytus collaris
1.3 Crotaphytus bicinctores
2.3 Pogona vitticeps (snow and red/gold)
1.0 Iguana iguana

To give an outline of my thoughts, I'd like to make the cage dimensions somewhere along the lines of 60" x 24" x 36" or, preferably, 72" x 24" x 36" (length by width by height)

1.) Is there a particular plywood that would stand out as more efficient for this type of enclosure? Particularly one that wouldn't sag at lengths of six feet.

Medium density overlay (MDO) is supposedly a bit more rigid than the standard plywood but more importantly has a resin impregnated veneer that is exterior rated and has some moisture resistance. I would still add more moisture resistance but MDO is a good start. It used to be very inexpensive but I understand its price has increased more than other plywoods. Not sure why.

Most plywoods come in 4x8 sheets, meaning a lot of waste with the sizes you mentioned. You might consider tweaking your dimensions slightly. Or you could go with true Baltic Birch plywood which comes in 5x5 sheets and maybe have a base size of 60 x 30.

2.) Would it be a good idea to line the cage with FRP? If so, how would I go about laminating the FRP to the plywood? Is there a better alternative for waterproofing?

I'm not a fan of FRP unless it is needed for abrasion resistance -- like a large Varanid lizard scratching on it. It does work very well for that. And again, in the sizes you mentioned you'd be wasting a lot of FRP since it comes in 4x8 sheets.

There are various options for sealing plywood, including vinyl film, contact paper (shelf liner) or other sheet or roll plastics.

Then there are the paint on liners, which can be epoxy resin, polyester resin, and both solvent based and waterborne epoxy paints. Even cheap Drylok seals plywood, although it leaves a rough and hard to clean texture. Some of the non-textured truck bed liners have also been used.

3.) I plan on mounting the heat panels directly to the FRP interior; is it possible that the heat could cause the FRP to separate from the plywood?

If you use regular FRP adhesive, then no. Besides RHP's have a radiant barrier so the back of them actually does not get that hot.

You might want to pick Nate's brain about an idea he has brewing for large cages. It might sound expensive but once you price plywood plus a sealer you might be pretty close to what he has in mind.

He and I have been discussing this offline so feel free to email me as well.
-----
Currently keeping:

6.10 Gonyosoma oxycephalum (Javan, mixed colors)

1.1 Philodryas baroni

1.1 Lampropeltis triangulum multistriata

1.0 Rhodesian Ridgeback

Thanks for the prompt response, Chris.
I do like the idea of using Baltic Birch, in which case I would just make the smaller 60" by 24" by 36" (length x width x height) enclosure. I also really like the look of the Baltic Birch. Would the plywood likely sag in the center at this size? That would be my main concern, as I plan on stacking the cages and they will contain a fair amount of substrate and branches.
I actually spoke to Nate last night, and he also leaned against the FRP idea, suggesting that bar-top epoxy would be a good alternative. Is there a particular brand or type that would be best in this application?
Another idea that Nate brought up would be to use door panels instead of plywood, as they are factory-cut and advantageous in some respects. One of my other concerns stems from the fact that if I do decide to build these cages, I will have to have Home Depot make the cuts as I don't have access to a table saw, and I'm concerned that they may not be particularly precise.
Thanks again.

-----
Roy Blodgett
Green Man Herpetoculture
royreptile@yahoo.com

1.1 Spilotes pullatus
2.2 Pseustes sulphureus
1.1 Pseustes poecilonotus poecilonotus
1.1 Lystrophis pulcher
1.1 Boiga dendrophila dendrophila
1.2 Crotaphytus collaris
1.3 Crotaphytus bicinctores
2.3 Pogona vitticeps (snow and red/gold)
1.0 Iguana iguana

I think you could build them at this size with minimal sagging. To minimize sagging you would want the lower most cage on a perfect flat and supported surface (placing the bottom cage on a 2" thick sheet of styrofoam works well to achieve this) and also including upper and lower lips inside of the cage for support. I would probably also include a few strips of plywood hidden behind the upper lip for extra support.

All of the bartop epoxy resins are very similar. If you're building multiple cages at once I would order Kleer Koat in bulk as it's still the cheapest price I have found. You should compare the price with shipping to Envirotex Lite that you can probably find locally. Last time I checked with shipping costs Kleer Koat was still cheaper if ordering at least two gallons.

I like the bartop epoxies but they go on so thick that they end up being expensive. You can pour them thinner but this is a lot more difficult across large surfaces. I would not recommend this if it's your first time. You need to warm up the epoxy to get it to run thin which means it sets up quicker. Not easy to do. You could possibly get away with this for the walls but not the floor of the cage.

West Systems epoxy with one of their specific hardeners cures stronger that bartop epoxy and looks as good or better. On paper it looks very expensive but since you can brush or roll it on you can use a lot less, thereby saving money.

As far as hollow core door blanks, I think they offer some advantages. They tend to be very close to perfectly square and flat, unlike plywood and obviously sag less than plywood given their modified torsion box construction. If you look in your paper or at building supply stores you can often get used ones for cheap or even free. And even better, the older doors tend to be of much better quality.

I have only weighed on HC door, a cheap on at that, a cage built from it would have weighed about the same as one built from 1/4" PVC and considerably less than one built from 1/2" PVC or HDPE.

The big advantage for you is that they are darn near the size you already want. In your case you would just adjust the size of your cages to 80" long. I don't believe it would be worth it to cut 8" off just to get a 72" long cage.

The primary concern I have with HC doors might be a strength disadvantage of the thin plywood veneer on the cage floor. If you have a lot of substrate I would worry about flexing inbetween the interior grids. One obvious argument against this is that wooden kayaks and canoes are made from similar plywood and they withstand much greater pressures when in the water and carrying a full load. Of course these boats also have a layer of fiberglass cloth which you could add in the future if you needed it.

I have more thoughts on HC door blanks but I'll hold off on that for now unless you pursue that route.

Home Depot does not carry the true 5x5 Baltic Birch. You'll likely need to get it at a lumber yard that caters to the cabinet industry. Or maybe even buy it direct from a cabinet shop and have them cut it for you. Even if you found it at Home Depot I would not have them cut it. Due to corporate policy they are not allowed to clamp stop blocks to their panel saws which means results are not always so good. I have had them cut wood but it is always hit or miss.
-----
Currently keeping:

6.10 Gonyosoma oxycephalum (Javan, mixed colors)

1.1 Philodryas baroni

1.1 Lampropeltis triangulum multistriata

1.0 Rhodesian Ridgeback

You might ask Rob Carmichael about his large plywood cages sealed with Contact Paper. See how they are holding up and what he likes and dislikes about them.

I mention this because he is over on the Indigo forum where you hang out and his cages are large and probably setup closer to what you'll use for Spilotes and Pseustes. Contact Paper previously has mostly been used in smaller and perhaps less decorated cages so the fact they have lasted a long time may not be relevant.
-----
Currently keeping:

6.10 Gonyosoma oxycephalum (Javan, mixed colors)

1.1 Philodryas baroni

1.1 Lampropeltis triangulum multistriata

1.0 Rhodesian Ridgeback