Devout cat lover—had cats all my life. They all have their own unique personality, but the Maine Coon has definitely become my favourite.
Cat Trees Must Be Adapted for Gentle Giants
Anyone who owns a Maine Coon will know they’re just too big and heavy for ordinary cat trees.
Ordinary cat trees are designed to support the weight of the average domestic cat of between 5 lbs. and 10 lbs., but Maine Coons (often referred to as 'gentle giants’) can weigh anything from 15 lbs. to 25 lbs. Greebo, our Maine Coon, is 17 lbs.
The cat tree we bought years ago (which is perfectly adequate for any standard cat) quickly buckled and broke under the weight of Greebo, so I had to repair and strengthen it. I did this at the time by dismantling the tree to feed a wooden post through the middle of the hollow tubes, and then firmly securing the post to a solid base.
Adapting an Existing Cat Tree and Expanding It Into a Cat Highway
Our cat tree was previously situated in our living room, where it took up a lot of valuable space and partially blocked access to our French doors. So when we built a new conservatory, with ample space in one corner for the cat tree, we moved it there and took advantage of the extra space to expand it into a cat highway.
This article is about how I strengthened, modified and expanded our cat tree into a cat highway. I give a detailed step-by-step guide to how I adapted the tree to fit snugly into the space, and how I expanded it into a cat highway, incorporating one of the roof beams into the design.
Cats Love Climbing
Strength Is Key to Durability
In relocating our cat tree to the conservatory I took the opportunity to strip it down and reconstruct it using stronger materials, better befitting a Maine Coon cat.
In particular, the platforms in the original cat tree, apart from being a little small for large cats like Maine Coons, were lightweight construction made from half-inch medium-density fibreboard (MDF). They are capable of supporting cats weighing up to 10 lbs quite easily, but do tend to give a little under the weight of large-breed cats heavier than 15 lbs.
Therefore, using the existing cat tree as a template guide, I made the new platforms a little larger, thicker and stronger by using 3/4 inch plywood rather than MDF, and re-engineered the construction so that each platform would be firmly fitted into place and capable of handling the weight of a 17 lb cat jumping onto it.
Our Half-Breed Maine Coon Cats on Their Old Cat Tree at Playtime
Reconstructing the Original Tree
The tree I modified consisted of:
- Three platforms, each separated by a thick cardboard tube wrapped in rope
- Base unit
- Mushroom-shaped cat bed, and
- Scratching ladder
The existing rope cylinders, cat bed and ladder were incorporated into the new tree, but the platforms (which were made bigger) and the base unit were reconstructed from scratch.
Rounded Edges and Corners
To make the platforms, I marked out and cut each one to size from 3/4 inch plywood, making them slightly larger than the originals.
Once constructed and fitted in place, one corner would be in the corner of the conservatory and another flush against the wall. These two corners needed to remain square. However, for the aesthetics and in keeping with the design of the original tree, I wanted the other two corners to be rounded.
I would also be covering the platforms in faux fur (just like the original), therefore each edge would need to be smoothed down and rounded off so that there couldn’t be any sharp edges to snag the fabric.
To make the two rounded corners for each platform I placed a large paint pot on each corner in turn, and marked around it with a pencil as a guideline for cutting the curves with a jig saw.
I then rounded off the top and bottom edge of each platform with a router.
Strengthening the Central Support for the Top Platform
In the original cat tree the top platform was fixed in place with a bolt fitted to the top of the roped tube that screwed into a pronged tee nut fitted to the underside of the platform. With the weight of our Maine Coon the nut had worked loose making the platform wobbly.
So in my redesign, while drilling the hole to accept the pronged tee nut in the centre of the new top platform, I also drilled the same size hole in the centre of a metal plate, and screw holes in each corner of the plate.
Therefore, once fitted, the metal plate would then hold the tee nut in place, preventing it from working loose in the future.
Cutting the Square Holes for the Support Post
As the support post goes through the two centre platforms I needed to cut a square hole in each one. The post needs to be a tight fit to give some lateral support to the platforms. But at the same time, the platforms should be just a fraction of an inch bigger than the post, so that during assembly the platforms can be pushed into position without having to force them down the post.
For such precision cutting of this nature, I find my SoniCrafter saw just the ideal tool for the job, because of its speed, ease of use and accuracy.
Demonstration on Using a SoniCrafter
Cutting the Cat's Play Hole
In keeping with the design of the original cat tree, which had a large play hole in the penultimate platform, I used the large paint pot as a guide to mark out the circle; as it happened to be just the right size.
I then drilled a hole big enough to fit the jig saw blade (to get it started) and then followed the pencil line to the cat's play hole.
Preparation for Fitting the Cat's Scratch Ladder
The cat ladder from the old cat tree is fixed in place with short bolts and tee nuts. Initially, I followed the design of the original tree and fitted one of the tee nuts to the underside of the lower platform and the other nut to the base.
Later on in the build, when I added the wall-mounted platforms as part of the cat highway, I moved the ladder to span between the middle platform on the tree and one of the wall-mounted platforms. To reutilise the nuts, when relocating the ladder, I just prised them out with a screwdriver and refitted them in their new position.
Upholstering the Platforms With Faux Fur
If you upholster the platforms, do it before assembling the cat tree.
Before assembling the modified cat tree I covered all the platforms and the base with faux fur fabric.
Other than not using foam (which is normally used when doing upholstery) the principle is the same, as follows:
- Cut the material to size, allowing for overlap around the edges.
- Tack down one edge with the few tacks or staples; in this case I used a staple gun.
- Pull the material taut at the opposite end and, while holding it firm, tack it in place with a few tacks. One tack in the middle and one at each end is the minimal that’s sufficient at this stage.
- Fold in the corners (like making a bed) and tack down.
- Then tack down one of the sides, and
- As before, pull the other side taut while you quickly tack it in place.
- Finally, go around all the edges, pulling them taut as you add tacks or staples about every half inch.
The reason I didn’t use foam is that foam wasn’t used in the original cat tree, and, unlike us humans, cats are quite comfy on a firm surface. Albeit, as most cat owners know when they discover their clothes all covered in fur, cats do love sleeping on soft fabric.
So whether you use foam or not is optional, but if you do decide to use it I would recommend 1/4 inch foam.
Assembling the Support Post and Platforms
With all the platforms and the main base upholstered, it was time to fit the support post to the main base, and to start reassembling the tree as follows:
- Secure the support post to the base with long screws, screwed into the post from the underside of the base.
- Slide the first rope tube down the support post.
- Screw four angle brackets to the post, one on each side just above the rope tube.
- Slide the first platform into position, and screw it into place from the underside using the outermost screw hole in each of the four angle brackets.
- Slide the next rope tube down the post and add angle brackets as before; to support the middle platform.
- Push the last rope tube down the support post.
- Finally, fit the bolt to the top of the post into which the top platform is then screwed into place.
Refitting the Scratch Ladder and Cat Bed
And Working Around the Cat Flap
The modified cat tree is right next to the cat flap, which requires full access for us to be able to close it in the evening (after both cats come in for the night) without having to move chairs out of the way or get in behind other furniture.
I say cat flap, but it’s actually a small dog flap as Maine Coons are too big to fit through a standard cat flap.
Although we can’t block the cat flap, because of the need for unrestricted access, I utilised the space by adding a platform above it, to which I fitted the mushroom-shaped cat bed, securing it in place with a large bolt screwed into the rope tube from underneath.
At the back of this platform, I cut out a narrow slit the width of the drop-down cover to the cat flap, with a small semi-circle in the middle (big enough to get a hand through) so that we can lower the plastic front in the evening to securely lock the cat flap. To some extent, when it is in the closed position over the cat flap, the plastic cover helps keep drafts out during the winter months. I have since added a padded cover that bolts into place over the cat flap on a night to add insulation.
The main base, on which the modified tree sits, is also raised because there’s another cat flap underneath it which leads into the house from the conservatory.
The cat ladder was initially fitted to this base, but as mentioned above, has since been moved to span between the cat tree and one of the wall-mounted platforms forming part of the cat highway.
Transforming the Cat Tree into a Cat Highway
With the modified cat tree in situ, and with spare wall space next to it, I decided to add wall-mounted platforms, and utilise one of the roof beams in the conservatory, to expand the tree into a cat highway.
Below is a quick guide on what I did to achieve this.
Sourcing the Wood
When building the conservatory, we replaced our old solid teak wood French doors with new UPVC (unplasticized polyvinyl chloride) French doors. I then put the old doors at the back of my workshop as salvaged wood for recycling in future DIY projects such as this.
I used the salvaged wood, in fact, to make the shelf supports, which in order to take the weight of a Maine Coon need to be securely anchored to the wall.
Making the Shelf Supports
I prepared the recycled wood from our old French doors and turned it into shelf supports for the cat highway as follows:
- Calculated the wood I needed, which happened to be the best part of one side of a French door.
- Took the surface back to the bare wood with a belt sander.
- Used a sander fitted with fine grade sandpaper to smooth the surface, and rounded the edges; a palm or orbital sander would be fine for this.
- Cut the shelf supports to the same length as the width of the wall platforms, which I’d already cut to size from plywood.
- Rounded off all the edges with a sander on the shelve supports and plywood platforms.
- Drilled a hole at both ends of each end shelf support, large enough for the frame-fixing screws that would be used to securely fix the platforms to the conservatory wall.