Catios & Safety / Building techniques and best practices to achieve safety:
If you read my “What is a catio?” page you learned about the benefits that providing an outdoor experience for indoor cats can provide. However, if we are to provide enclosed outdoor spaces for indoor cats it must be done with safety as the utmost priority. When I build a catio, safety is my primary concern: the safety of the cats so they can’t escape and keeping them safe from other cats or wild animals who might visit the catio. As a lifelong pet owner, I consider the safety and well-being of our pets to be my highest priority, and I always keep it top of mind when I design and build catios for my clients. Safety with regard to catios involves many considerations.
Ken’s 5 basic elements to catio safety:
1) A catio structure must be well-built and sturdy. As a carpenter who tends to overbuild structures for strength and longevity, my focus is to employ building techniques that withstand the test of time and usage. By nature, catios are outdoor structures and outdoor structures must be able to stand up to the elements. My philosophy is: when in doubt, build it stronger. I have never purchased or assembled a catio “kit” such as can be found online, but I have had clients who have purchased these kits tell me that they tend to be somewhat flimsy and not well-built. While a cat owner can certainly save money by purchasing a catio kit (be sure to read the reviews!), I believe a cat owner will ultimately be better satisfied with a catio built by a reputable carpenter or builder.
2) Screening vs welded wire: When a cat owner decides to build or have a catio built, they have a choice to make. Do they utilize screening or welded wire? “Pet safe” screening is available and can typically stand up to a cats claws and the potential for shredding, depending on the quality of the screening. I have built one catio where my client chose pet safe screening as opposed to welded wire, but the client was confident that their cats wouldn’t go after the screening with their claws. Although it’s important to keep in mind that any catio may someday be occupied by a new generation of cats living in the home and there is no guarantee that those new cats won’t be prone to shredding behavior. However, some catio owners also choose pet safe screening to avoid bugs getting into the catio (or into the house via a door or window). Most catios accessed via a window, and in some cases via a door, utilize window or door inserts with cat doors and this can reduce the potential for bugs to get into the home. If a homeowner wants a catio large enough so that they can occupy the catio with their cat(s) they may want to keep mosquitoes and other bugs out so they can better enjoy the outdoors, and the catio with their cats, without being eaten alive by bugs. And so, they may choose pet safe screening for this reason.
In all other cases, the catios I have built have utilized welded fencing wire, also sometimes known as “hardware cloth”. Galvanized or black wire are the best welded wire options, typically in a 2” by 3” or 2” by 4” grid size. These types of welded wire can be found at most home centers. True hardware cloth is typically 1/2” by 1/2” and is somewhat unattractive and doesn’t afford your cat(s) an open view of the outdoors. However, hardware cloth can sometimes be found in a larger 1” by 1” or 1″ by 2″ grid size and this may be chosen if the cat owner is concerned about birds getting into the catio. To date I have never read about or had a client tell me that birds have entered their catios where 2” by 3” or 2” by 4” welded wire was used, and I have never seen birds in my own catio which has a similar welded wire grid size. Welded wire is mounted to the catio frame with the 2″ opening mounted horizontally, which is too small an opening for a bird’s wingspan. Vinyl coated wire should be avoided as the vinyl will crack and decay from the elements over time, and the wire inside the vinyl coating is typically very thin and weak. Chicken wire is unappealing, difficult to make taut because of its flexibility, and has a very short life span, and is a poor choice for catios.
3) Providing an additional egress: With the exception of small window box catios, or catios that are basically screened in porches, I always advise my clients that an additional egress be designed into the catio. This is somewhat specific to catios where a window (or a cat door in a wall) is used as the only access point for the cat(s), which is very common with catios. The reason for this is so the cat owner can extricate the cat via another entry point in the event of an emergency (or you simply can’t get the cat to come back inside when you want it to) as opposed to trying to retrieve the cat from, say, the window that the cat uses to access the catio. Important: When using an additional egress to remove a cat from a catio in order to get the cat back into your house, always use a cat carrier! Never attempt to carry the cat from the catio back into your home in your arms!
And, obviously, if the catio is designed so that the cat owner can occupy the catio with their cat(s), they would need a “human door” to do so unless the catio is accessed from a door or porch door. And so, when designing an additional door into a catio, the door must be secure, and I feel it best if the door latches can be locked. If you go to the 35 second mark of this video you will see the lockable door I designed into a catio I built in 2024. In the case of my catio, I designed it around repurposing a doggie exercise pen. Because of this, the catio is only 2’ deep by 4’ wide and is not large enough for us to occupy the catio with the cats (and it is accessed via a window). But the doggie exercise pen has one panel with a built-in door, and so that is the additional egress point required.
4) A catio must be built so that the cats can’t escape and other cats or wild animals can’t get into it. This may seem obvious but it can’t be overstated, and the building techniques I describe above are meant to assure this. Some other considerations in this regard would be to assure, when building a catio at ground level, that the cats or outside critters (or your dogs) can’t dig under the foundation. This can be accomplished via several techniques including extending and burying welded wire around the catio foundation, surrounding the catio with paving stones, or adding paving stones as a patio to build the catio on top of. Ideally, when building at ground level, I would be inclined to have the bottom frame of the catio raised up off of the ground (by using cinder block pylons or similar supports for the frame) and build the lower level of the catio with a solid floor. The roof is another consideration. While a catio roof can be built with the same welded wire or screening I describe above, I prefer a solid roof that can withstand things falling onto it such as tree branches. My go-to is corrugated galvanized or aluminum metal – I prefer metal over corrugated polycarbonate type roofing which can fade and crack over time and can get dirty from leaves and debris accumulating on it.
5) Things the cat owner can do to assure safety: a) Keep your cat(s) up to date on vaccinations b) Don’t leave food in the catio c) If you live in a place where you get winter, you may want to limit your cat’s access to the catio during colder months. Our 15 year old cat, Lucia, has asthma and we don’t allow her access to the catio during cold weather d) Depending on your comfort level, you may choose to not allow your cat(s) access to the catio when no one is home.
