Rio Bravo Reptiles: Building Outdoor Enclosures

How To Build Outdoor Cages For Lizards

Many types of lizards benefit from regular exposure to natural sunlight. And it is possible to see behaviors in lizards kept outdoors otherwise not seen in terrariums. It is not difficult or expensive to construct safe outdoor enclosures. Following is a photo-essay on one good way to build quality outdoor lizard cages. Note: this caging system relies on the design and materials of the surround to prevent escape. Covers, if provided, are in place as a deterrent to birds, house-cats and other small predators which may attempt entry. The general dimensions recommended have been proven escape-proof for Sauromalus sp., bearded dragons and two species of Uromastyx. Large athletic lizards like Iguanas or many Varanids will require additional security considerations. Materials for this cage are: treated landscape timbers, dimensional lumber (as is sold for outdoor decking is perfect), corrugated fiberglass roofing and galvanized drywall screws, 5/8 and 2-1/2" long and perhaps a few nails. I have been asked about the use of sheet metal or corrugated metal roofing. Sheet metal has no strength in compression and corrugated metal is difficult to work with. Both also will quickly rust in the earth and on hot sunny days create an oven-like effect inside the pen. Tools: a good spade, a circular saw, cordless driver-drill, a level for vertical and horizontal planes and a hammer. Unless you are really handy the first one of these you build will also require a helper.

Begin by locating an area free of large bushes and trees where digging is not too difficult. Consider year-round sun exposure as well, trees and buildings may block the sun as the seasons change. Remove turf-grass and level the grade. You can construct this type of cage on a slope but it will require special cutting and fitting of the piers and siding, shorter on the up-side and longer on the downward end.

A ditch 10" to 12" wide and about 14" deep is dug, the middle of the ditch represents the finished dimension of the enclosure. Size is a matter of preference but experience has shown that wall height greater than about 30' of the smaller inside dimension creates too much shade late and early in the year, even at our latitudes (25 deg. N.) This means small cages do not work. On the other hand materials dimensions limit the practical size to the 10'-12' mark. In our experience a 10' by 8' enclosure is a very good size for breeding groups of the species mentioned above. Certainly, any size cage could be made using this design with little additional engineering.

Corner posts are not used in this design so the ditch does not have to be absolutely square, or rectangular. However, as in all such projects, each step you complete is the foundation for the next. The neater the ditch, the easier rest will go and the result will be more pleasing. Labor saving tip: throw about a third of the soil removed for the ditch inside the new cage area. This is backfill and if you pile it all outside you will have to lift each shovel-full over the new walls to get it into the ditch again.

Cut your landscape timbers in half. View the photo to see the off-corner placing of the posts, a shallow hole is dug about a foot or 15" from the absolute corner just deep enough for the post to remain upright while working and leaving the tops even with one-another. Remember, the center of the ditch is the wall location so the posts are installed close to the outside of the ditch. The correct height is 32" to 34" above the finished grade. The straighter and more even these posts the better but again, this design is very accommodating to small goofs. Be sure also that the best flat side of the landscape timbers face inward and parallel to the other on each cage side.

This view more clearly shows the relationship of the posts to one-another and the corners. The next step is the horizontal frame to support the siding. The bottom set is already installed in this view, 1x6" decking lumber was used.

Start by measuring the length of two opposite sides from each 'virtual' corner, add a few inches to that measurement and cut the two boards. Install them with long screws to the inside face of the posts. Make them as level as practical and leave one-half their width in the ditch and the other above grade. The exposed (above finished grade) portion protects the siding from weed-eaters or other incidental damage.

After checking that the two sets of posts and bottom-rails are vertical, measure, cut and install the other pieces. It is a good idea to also place screws at the corner juncture of the rails. Pre-drill the hole to prevent splitting. Now follow the same procedure for the four top rail boards. These define the top of the walls and can be fudged up or down a little to get a flat surface horizontal to the ground. This next photo shows the completed frame.

Installing the siding. Assuming the 32-34in. finished wall height it is practical to purchase the fiberglass in 12' lengths and cut each piece into three 4' sections. These sections are hung even with the top rail edge, leaving the remaining 14-15" extended down into the ditch.

The above photo shows the siding being installed. Start by pushing the first piece deep into any one corner until the center corrugation contacts the juncture of the rails. Making sure the vertical edges of this first section are fairly straight use the 5/8" screws to fasten it in place. It is best not to place screws into the very corner and don't use too many screws. Continuing in both directions from this corner, install most of the remaining sections, overlapping each new section two corrugations with the previous. Other than a top and bottom screw no fastening is needed or recommended along this over-lap. When you encounter the next two corners push the siding in as you did the first section.

When you are within 5 or 6 pieces of completion at the last corner stop and measure the remaining length of wall. Comparing it to the work already done you will see that the last section will not end with an even 2 corrugation overlap with its' partners. Rather than having this entire mismatch absorbed in the corner adjust the overlap on the remaining sections to get an even appearance.

Now cut and install the sections to cap the top rail. Consider that the cap should cover the exposed wall corrugations. This next photo shows the finished walls with the cap installed. Note that the bottom rail is exposed about 1/2 its' width as was recommended above. This design is very sturdy (as you can see) and presents a pleasing appearance.

Backfill the ditch evenly, inside and out, tamp the dirt firmly. Use coarse construction gravel to fill the top one-half of the inside of the ditch. The gravel discourages digging along the perimeter and promotes drainage. You can also build-up low areas with gravel as shown in this next image.

Finishing the interior grade with coarse sand completes a very good substrate.

Use caution when placing structures inside the cages for your lizards to use. Make certain rocks and plants don't provide an escape route, leave at least 36" in open space in all directions from any such structure to the top of the surround. Lizards inevitably dig under rocks and boards so also be sure that your rock-piles are set firmly enough that they will not collapse and injure or crush your animals.

Here's a look at the finished cage. Anyone interested in tips on how to construct domes as seen here drop me a note.

This system makes a great stand-alone cage or, as seen in the last image, can be part of a much more sophisticated habitat. —Gus